Why is sexual reproduction so much more common than asexual (in macroscopic organisms)? Fundamentally, what makes it better?

Why is sexual reproduction so much more common than asexual (in macroscopic organisms)? Fundamentally, what makes it better?

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I'm experimenting with an evolutionary method of creating a neural network. I use an asexual approach, but I've seen others use sexual approaches.

So I'm interesting in learning what's better about sexual reproduction as apposed to asexual, and biology is probably the best way to approach that question. So, why is sexual reproduction so much more common than asexual (in macroscopic organisms)? Fundamentally, what makes it better?

I'm struggling to understand what the combination of two gene sets does that couldn't be achieved by mutations to a child of asexual reproduction.

Genetic diversity is needed to prevent everyone from dying of the same disease. This is the problem with monocultures. Higher organisms are more susceptible to disease and thus reproduce sexually.

Furthermore, basically all organisms exchange DNA so they are effectively sexual.


Abstract In 1858, two naturalists, Charles Darwin and
Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwin’s Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwin’s perspective. Weismann’s neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian
Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwin’s dilemma (the apparent missing Precambrian record of life) has been resolved.
Next, the historical development and structure of the
“modern synthesis” is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and molecular evolution, experimental bacterial evolution, and computer simulations (in silico evolution of digital organisms). In addition, we discuss the expansion of the modern synthesis, embracing all branches of scientific disciplines. It is concluded that the basic tenets
Dedicated to Prof. Dr. Dr. hc mult. Ernst Mayr on the occasion of his 100th birthday
U. Kutschera ())
Institut für Biologie,
Universität Kassel,
Heinrich-Plett-Strasse 40, 34109 Kassel, Germany e-mail: [email protected]
Fax: +49-561-8044009
K. J. Niklas
Department of Plant Biology,
Cornell University,
Ithaca, NY 14853, USA

of the synthetic theory have survived, but in modified form. These sub-theories require continued elaboration, particularly in light of molecular biology, to answer openended questions concerning the mechanisms of evolution in all five kingdoms of life.

Physicists and chemists investigate the properties and interactions of objects, such as electrons, photons, and atoms, which are physically uniform and invariant in their characteristic traits and behavior. Accordingly, a single experiment adducing the properties of a single entity (e.g., electron or proton) can be used to extrapolate the properties of all comparable entities in the universe. In biology, the “science of the living world,” both past and present (Mayr 1997), the situation is very different. The organisms biologists study, which are typically randomly drawn from populations, manifest astonishing variation as a consequence of genetic recombination and random genomic changes. Thus, with the exception of identical twins or cloned individuals, no two members of the same species look exactly alike (even identical twins may differ physically as a result of their individual histories).
Because this general rule of “biological variability” applies not only to plants and animals, but also to microorganisms that lack the capacity for sexual reproduction, the concept of “types” is radically different in the context of biology versus that of the physical sciences.
However, there are limits to biological variation and these literally shape evolutionary history. No population is ever capable of generating all possible theoretical genomic variants, in part because sexual genetic recombination is random and because the existence of any particular population is finite. Therefore, biological variation, which provides the “raw material” for evolutionary change, is confined by random events. Nevertheless, nonrandom processes also shape evolution. The “struggle for existence” among the offspring of each generation eliminates genomic variants that are less adapted to their

Table 1 List of the principal propositions of Darwin’s theory, extracted from the Origin of
Species (Darwin 1859, 1872)

Supernatural acts of the Creator are incompatible with empirical facts of nature
All life evolved from one or few simple kinds of organisms
Species evolve from pre-existing varieties by means of natural selection
The birth of a species is gradual and of long duration
Higher taxa (genera, families etc.) evolve by the same mechanisms as those responsible for the origin of species
The greater the similarities among taxa, the more closely they are related evolutionarily and the shorter their divergence time from a last common ancestor
Extinction is primarily the result of interspecific competition
The geological record is incomplete: the absence of transitional forms between species and higher taxa is due to gaps in our current knowledge

environment. Those that survive pass their genetic information on to the next generation. In this way, evolution is the summation of random events (e.g., mutation and sexual recombination) and natural selection, which is largely non-random.
This fundamental process – the “principle of natural selection” (Bell 1997) – was conceived independently by two nineteenth-century British naturalists, Charles Darwin and Alfred Russel Wallace, and has been substantially elaborated upon in the early part of the twentieth century with the rediscovery of Mendelian genetics and subsequent advances in population genetics. Importantly, this “modern synthesis” continues to the present day, as insights are gained from diverse fields of study, particularly molecular biology, which is rapidly detailing the precise mechanisms whereby genomes (and the phenotypes they engender) are altered.
The aim of this article is to review the historical development and the progress made in evolutionary theory from the time of Darwin and Wallace to the present day. Clearly, no such summary can ever be complete, because the literature dealing with evolutionary biology is vast and complex. Here, we only sketch the broad outlines of the basic history of evolutionary theory and enquiry. To do this, we first describe the development of the idea of evolution and its subsequent establishment as a documented fact. We then outline the development and expansion of the modern synthetic theory from 1950 to the present. Although many major questions in evolutionary biology remain unanswered, no credible scientist denies evolution as “a fact.” Yet, many scientists continue to explore and debate precisely how the mechanisms of evolution work.

Charles Darwin and Alfred Russel Wallace
In August 1858, two of the most influential publications in the history of biology were published. These concurrent papers by Darwin and Wallace contained a “very ingenious theory to account for the appearance and perpetuation of varieties and of specific forms on our planet” (foreword by C. Lyell and J. Hooker). Therein,
Darwin and Wallace (1858) presented for the first time the hypothesis of descent with modification by means of natural selection. This hypothesis makes five fundamental assertions: (1) all organisms produce more offspring than

their environments can support (2) intraspecific variability of most characters exists in abundance (3) competition for limited resources leads to a struggle for life
(Darwin) or existence (Wallace) (4) descent with heritable modification occurs and (5), as a result, new species evolve into being.
Unlike Wallace, Darwin supported his arguments with a large body of facts, drawn mostly from breeding experiments and the fossil record (Table 1). He also provided detailed direct observations of organisms existing in their natural habitats (Darwin 1859, 1872). Thirty years later, natural selection’s co-discover published a series of lectures under the title Darwinism (Wallace
1889), which treated the same subjects as Darwin but in light of facts and data that were unknown to Darwin (who died in 1882). A detailed comparative analysis of the
Darwin/Wallace publications reveals that Wallace’s contributions were more significant than is usually acknowledged, so much so that the phrase “the Darwin/Wallace mechanism of natural selection” has been proposed to acknowledge the importance of the “second Darwin”
(Dawkins 2002 Kutschera 2003a). Although Darwin is usually credited as the “principal author” of evolutionary theory, Ernst Mayr (1988, 1991) points out that it is not correct to refer to “Darwin’s theory of descent with modification” (the word “evolution” does not appear in the original 1858 papers of Darwin and Wallace only in later editions of The Origin of Species and in Wallace’s
If we equate the word Darwinism with the content of the book On the Origin of Species, we can distinguish between five separate concepts:

Evolution as such
Theory of common descent
Multiplication of species
Natural selection (Mayr 1988, 1991).

The first two propositions are discussed in the next section. Thereafter, the development of Darwin’s original theory is described (see Fig. 1).

Fig. 1 Scheme illustrating the historical development of the concept of evolution: from the hypothesis of Darwin and Wallace
(1858), through Darwin (1859, 1872), Wallace (1889) and Weismann (1892) to the synthetic theory (Dobzhansky 1937 Mayr
1942 Huxley 1942 Simpson 1944 Rensch 1947 Stebbins 1950 and others)

Evolution as a documented fact
The concept that all organisms on Earth have evolved from a common ancestral life form by means of genomic and morphological transformations (evolution as such) was not “invented” by Darwin or Wallace. Mayr (1982) and others have shown that the idea of organismic evolution can be traced back to several Greek philosophers (see also Bowler 1984 Ruse 1996 Junker and
Hoßfeld 2001 Kutschera 2001 Storch et al. 2001). Likewise, the hypothesis of continuous transformations was proposed by numerous eighteenth- and nineteenth-century authors who are credited by Darwin in the first chapter of his book. However, Darwin (1859) was the first to summarize a coherent body of observations that solidified the concept of organismic evolution into a true scientific theory (i.e., a system of hypotheses, as defined by Mahner and Bunge 1997) (Table 1).
When Darwin (1859, 1872) proposed his theory of descent with slight and successive modifications (gradualistic evolution), the available fossil record was still very fragmentary. Indeed, the early fossil record (periods prior to the Cambrian) was entirely unknown or unexplored.
Nevertheless, Darwin (1859, 1872) concluded that if his theory of evolution was valid, aquatic creatures must have existed before the evolutionary appearance of the first hard-shelled organisms (such as trilobites) in the Cambrian period about 550–500 million years ago (mya).
Darwin’s dilemma, i.e., the apparent missing Precambrian

fossil record, was used as a major argument against his proposal 1 (evolution as a fact).
This dilemma no longer exists. Scientists have explored the Precambrian in detail (see Schopf 1999 Knoll
2003 for summaries). We now know that life is far more ancient than believed in Darwin’s time. We also know that these ancient forms of life were the ancestors to all subsequent organisms on this planet. Some of the evidence for these new insights is as follows. Geochronologists using techniques such as the uranium–lead (U–Pb)method for estimating the age of rocks now date the origin of the Solar System at about 4,566€2 mya
(Halliday 2001). This extensive age is divided into two major “eons,” the Precambrian (4,600–550 mya) and the
Phanerozoic (550 mya to the present). The older and much longer of the two (the Precambrian) is composed of two “eras,” the Archaean (from 4,600 to 2,500 mya) and the Proterozoic, which extends from 2,500 mya to the end of the Precambrian. The shorter and younger Phanerozoic encompasses the most recent history of the Earth, which is roughly 15% of Earth’s total history (approximately
550 Ma). In turn, the Phanerozoic is divided into three eras: the Paleozoic, Mesozoic, and Cenozoic (Niklas
1997 Cowen 2000 Kutschera 2001). A general scheme of the geological time scale with representative fossil organisms is shown in Fig. 2.
Based on detailed chemical studies of the oldest of these geological periods, geologists and paleontologists have established that life first emerged on Earth about
3,800 mya (after Earth ceased to be bombarded by extraterrestrial debris see Halliday 2001). The oldest stromatolites (layered rocks produced by communities of microorganisms) containing fossilized microbes are known from 3,450-Ma-old strata (Western Australia
Pilbara sequence), whereas the oldest microscopic threadlike microfossils, which are morphologically similar to extant cyanobacteria, are found in the bedded chert unit of the Archean Apex Basalt of Australia (age 3,465€5 Ma).
Data drawn from independent lines of evidence demonstrate that these prokaryotic microfossils are not artifacts they represent remnants of Earth’s earliest microorganisms (Schopf 1993, 1999 Knoll 2003).
Evidence for the extreme antiquity of life also comes from isotropic studies (Shen et al. 2001). Molecular fossils derived from cellular and membrane lipids (so called “biomarkers”) confirm that cyanobacteria-like organisms inhabited the archaic oceans more than
2,700 mya. These photoautotrophic microbes released oxygen that started to accumulate in the atmosphere at ca.
2,200 mya and subsequently transformed the Earth’s atmosphere (Knoll 1999). Paleontological and biochemical evidence also indicates that the first eukaryotic cells
(defined by a membrane-enclosed nucleus) occurred between 2,000 and 1,500 mya (Fig. 2), although key attributes of eukaryotic physiology probably evolved earlier (Knoll 1999, 2003 Martin and Russell 2003). The occurrence of sexually reproducing multicellular eukaryotic Protoctista (red algae) has been documented in remarkable detail (Butterfield 2000). Although there are

Fig. 3A, B Precambrian eukaryotic fossils (red algae) from the ca.
1,200-mya Huntington Formation (Canada). Populations of vertically oriented Bangiomorpha pubescens that colonize a firm substrate (A) and three individual filamentous multicellular algae with a bilobed basal hold fast (B). Bars: 100 m (A), 50 m (B)
(adapted from Butterfield 2000)

Fig. 2 Geological time scale with key events in the history of life, from the formation of the Earth to the present. All five kingdoms of organisms are included (Bacteria, Protoctista, Animalia, Fungi,
Plantae). Ma millions of years

some more ancient eukaryotic fossils, Bangiomorpha dated at 1,198€24 Ma is currently the oldest known multicellular eukaryote (Fig. 3). In the Bangiomorpha assemblage, other fossil multicellular eukaryotes were observed, whereas benthic microbial mats (prokaryotes) appear to be absent. These observations indicate that the rise of multicellular algae at ca. 1,200 Ma coexisted with

and may have caused environmental shifts through the
Meso-Neoproterozoic transition (Butterfield 2001).
Historically, Haeckel (1874) was the first evolutionist to propose that the earliest metazoa were microscopic organisms similar in morphology to the embryos (or larvae) of adult animals (gastraea theory). In Precambrian rocks dated at 570 Ma (Doushantuo Formation, China), multicellular organisms are preserved just before the
Ediacaran radiation of macroscopic “Vendobionta” (Bengston 1998). Fossil animal embryos preserving different stages of cleavage and multicellular structures with diameters measuring less than 250 m were discovered in
Precambrian strata. In addition, sponges and thalli of multicellular algae have also been found. These discoveries in Precambrian rocks document the existence of not only bacteria, cyanobacteria, and eukaryotic algae, but also the (putative) precursors of the soft (Ediacara) and hard-shelled macroscopic animals of the late Proterozoic and early Phanerozoic (Cambrian).
This brief summary shows that Darwin’s dilemma (the apparent missing Precambrian record of life) has been resolved, although the traces of cellular structures in Precambrian rocks are sparse and more fossils are required to further elucidate the “cradle of life” on our planet (Schopf
1999 Conway Morris 2000 Carroll 2001 Knoll 2003).
In addition to his concerns about the incompleteness of the fossil record, Darwin (1859, 1872) clearly worried about the apparent absence of intermediate forms (connecting links) in the fossil record of life, which challenged his gradualistic view of speciation and evolution. Indeed, with the exception of the famous Urvogel Archaeopteryx, which displays a mixture of reptile- and bird-like characteristics (Futuyma 1998 Mayr 2001 Storch et al.
2001), virtually no intermediate forms were known during

Table 2 Representative examples of intermediate forms linking major groups of vertebrates. The specimens were discovered, described or analyzed during the last 20 years and represent connecting links in the fossil record of vertebrates
Evolutionary transition (genus)
1. Fish/amphibian

2. Amphibian/land vertebrate
3. Reptile/mammal (Thrinaxodon)

4. Terrestrial reptile/ichthyosaur

5. Anapsid reptile/turtle
6. Dinosaur/bird

8. Land mammal/seacow
9. Hoofed land mammals/whales
(Ambulocetus, Rodhocetus)
10. Ancestor of chimpanzees/modern

Intermediate form fish/amphibian in the series Eustenopteron

380 Ma) – Panderichthys – Acanthostega (amphibian

363 Ma)
Intermediate grade between primary aquatic Upper Devonian amphibians and early tetrapods
Mammal-like reptiles that show a blend of mammalian and reptilian characteristics
Extinct marine reptile that shows features that are transitional between ancestral terrestrial amniotes and aquatic ichthyosaurs
Pareiasaur with turtle-like rigid body all osteoderms are united, forming a rigid covering over the entire dorsum
Bird-like four-winged dromaeosaurid that could glide, representing an intermediate stage between the flightless theropods and volant primitive birds such as Archaeopteryx
Primitive snake with limbs, transitional taxon linking snakes to an extinct group of lizard-like reptiles
Intermediate form of a primitive seacow with both terrestrial and aquatic adaptations
Connecting links between amphibious and terrestrial eventoed ungulates and aquatic whales
The most basal ape-like African hominid. Mosaic of primitive
(chimpanzee-like) and derived hominid features

Darwin’s lifetime. This dilemma has also been resolved by more recent discoveries of intermediate forms in the evolutionary history of many animal and plant lineages
(Kemp 1999 Zhou and Zheng 2003 Zimmer 1998).
Some examples that cover the past 370 Ma of vertebrate evolution are summarized in Table 2.
Darwin’s second postulate (the common ancestor, represented by “a few forms or one”) has been verified by a large body of molecular data that has altered our perspectives in many important ways, e.g., the “RNAworld” hypothesis (Joyce 2002). The principle of common descent is documented in the well-supported universal phylogenetic tree of life (Schopf 1999 Pace 2001).
The “universal ancestor” of all Earth’s organisms appears to have been a diverse community of prokaryotic protocells (Woese 2002) that subsequently evolved into true prokaryotic organisms attended by the emergence of the genetic code and subcellular constituents (Seligmann and
Amzallag 2002 Woese 2002 Martin and Russell 2003).
When these diverse lines of evidence are taken together
(see Fig. 2), there is no question that all life on Earth arose ca. 3,800 mya from a common ancestor, as originally proposed by Darwin (concepts 1 and 2). That Darwin struggled with the genetic mechanism of evolution because he was unaware of Mendel’s work is well known.
But his failure to know of such a mechanism cannot detract from his many important insights and seminal contributions to the subsequent development of evolutionary thought.

Clack (2002)
Rubidge and Sidor
Motani et al.
Lee (1996)
Xu et al. (2003)
Tchernov et al.
Domning (2001)
Thewissen and
Williams (2002)
Wood (2002)

The five theories that Mayr (1988, 1991) extracted from
Darwin’s Origin of Species concentrate on two separate aspects of organismic (biological) evolution: the evolutionary process as such, and the mechanisms that brought about (and still cause) evolutionary change. Whereas biologists no longer debate the existence of evolution as a fact of life (literally), the mechanisms that account for the transformation and diversification of species are still very much under investigation. Pertinent studies are usually carried out on populations of living organisms (neontology) in contrast to historical reconstructions of evolution based on the fossil record (paleontology) (Mayr 2002).
Theories of evolution (i.e., systems of hypotheses that are based on data) continue to be formulated to account in precise detail for the mechanisms of evolutionary change
(Mahner and Bunge 1997).
According to Mayr (1982, 1988) and other historians of biology (Reif et al. 2000 Junker and Engels 1999
Junker and Hoßfeld 2001 Junker 2004), the development of the modern theory of evolution can be divided into three stages (Fig. 1).
1. Darwinism
Historically, this stage is represented by the 1859 publication of Darwin’s book On the Origin of Species.
Specifically, it refers to the Darwin/Wallace principle of natural selection as the major driving force in evolution.
Since Darwin (1859, 1872) accepted Lamarck’s principle of the inheritance of acquired characteristics as a source of biological variability, it is equally fair to call this

the “Lamarck/Darwin/Wallace” period of evolutionary thought. 2. Neo-Darwinism
This stage in the development of evolutionary theory can be traced to the German zoologist/cytologist A. Weismann (1892) who provided experimental evidence against
“soft (Lamarckian)” inheritance and who postulated that sexual reproduction (recombination) creates in every generation a new, variable population of individuals. Natural selection then acts on this variation and determines the course of evolutionary change. Hence, neo-Darwinism
(i.e., the expanded theory of Darwin) – a term that was coined by Romanes (1895) – enriched Darwin’s original concept by drawing attention to how biological variation is generated and by excluding Lamarckian inheritance as a viable mechanism for evolution. Wallace (1889), who popularized the term “Darwinism”, fully incorporated the novel conclusions of Weismann and was therefore one of the first proponents of neo-Darwinism.
3. Synthetic theory
This novel system of hypotheses for evolutionary processes originated between 1937 and 1950 (Mayr 1982). In contrast to Weismann’s (1892) and Wallace’s (1889) neoDarwinian concept, the synthetic theory incorporated facts from such fields as genetics, systematics, and paleontology. Hence, the term “neo-Darwinian theory” should not be confused with the “synthetic theory” (or the phrase “neo-Darwinian synthesis” see Mayr 1991
Reif et al. 2000 Junker 2004).
Although the modern synthesis rested largely on data collected from eukaryotes, modern evolutionists have turned their attention to prokaryotes in an effort to deduce how life began and how sex evolved. When Darwin
(1859, 1872), Wallace (1889), and Weismann (1892) proposed their concepts of the mechanisms of evolutionary change, microbiology was in its infancy. Naturalists
(Darwin, Wallace) and cytologists (Weismann) studied macroscopic animals and plants. Like humans, these organic beings are diploid, sexually reproducing eukaryotic multicellular organisms in which each cell contains two sets of chromosomes (one set from each parent) other than their haploid gametes (females: eggs, males: sperm cells) that result from meiosis. After fertilization of the egg, the zygote develops into a new diploid (2n) individual (the next generation). As Fig. 2 shows, most of these complex multicellular organisms evolved late in the history of life during the Cambrian period (ca. 550–500 mya). Organisms such as these are currently the most visually apparent life forms on our planet, although prokaryotes
(bacteria, cyanobacteria) – microbes that have persisted since the Archaean (ca. 3,500 mya) – are still the most abundant (in terms of their collective biomass) and

Fig. 4 Epiphytic bacteria associated with the cuticle of the epidermal cells of a sunflower cotyledon (inset, arrow points to the region depicted). The scanning electron micrograph illustrates that bacteria are ubiquitous microorganisms that inhabit every ecological micro-niche where organic substrates are available. The arrowheads point to bacteria in the process of binary fission. Original micrograph prepared as described by Kutschera (2002). B bacteria,
C cotyledon, E epidermal cell. Bar: 10 m

ecologically diverse forms of unicellular life (Whitman et al. 1998).
However, the synthetic theory of biological evolution was almost exclusively deduced on observations and quantitative data obtained with eukaryotic, bisexual macroorganisms. This is one of several reasons why we propose that an expansion is necessary in order to incorporate the morphologically primitive (largely uniform) microorganisms (Fig. 4). These microbes reproduce asexually by binary fission, although recombination (horizontal DNA transfer) also occurs.
In the next paragraph the evolutionary synthesis (a historical process) is described. The reader should bear in mind that the data (and hypotheses) that formed the pillars of this period of theoretical development were exclusively obtained using animals and plants as experimental/observational systems.

Post-neo-Darwinian concepts
As pointed out by Mayr (1982, 1988), the most original
(and the last to be universally accepted) among Darwin’s five proposals was the theory of natural selection. It took

nearly 80 years until the majority of biologists adopted natural selection as the major shaping force in organismic evolution as opposed to one of four alternative and very popular concepts:


Throughout his book, Darwin (1859, 1872) mentioned that the “theory of creation” is erroneous and incompatible with his observations and data. In the last chapter of his work, entitled “Recapitulation and Conclusions,”
Darwin explicitly points out that species are not produced and exterminated by “miraculous acts of creation” (Darwin 1872, p. 504). Yet, creationism is still popular in the guise of “intelligent design,” which persists in the notion that organisms are “designed” by supernatural acts
(Kutschera 2003b Pennock 2003). Such arguments are based on a mixture of selected scientific data and superstition that are refuted by rational thought and data
(Futuyma 1995 Kutschera 2001).
Since Darwin (1859, 1872 but not Wallace 1889) believed in an inheritance of acquired characters, it is understandable that the concept of “soft inheritance”
(Lamarckism) was popular until ca. 1940. The work of
Weismann (1892), who had unequivocally refuted a direct effect of the environment on the parent–offspring germline in animals, was not universally accepted, i.e., the neoDarwinian theory of evolution was in part eclipsed by the old concept proposed by Lamarck.
The third idea, which can be described as “orthogenesis” (there were several competing models), was a misguided analogy between phylogeny and ontogeny. Its proponents believed in an endogenous tendency in evolution toward ever greater perfection and complexity.
Evolution was thought of as a programmed event that would ultimately lead to a predetermined end result. Just as in ontogeny, where the zygote develops into an embryo and thereafter into an adult organism, the orthogenesists postulate a genetic mechanism that ultimately leads to
“perfect” evolutionary products. Since a “universal” trend toward ever-increasing complexity is not documented
(Carroll 2001 bacteria still exist today, see Figs. 2 and 4) and since no “perfect” organism has ever been found, deterministic concepts such as orthogenesis were no longer taken seriously after 1940 (Mayr 1988).
The fourth alternative anti-selectionist theory of evolution was the idea of saltationist transmutationism. This concept, a brain-child of typological thinking, argues that one organism could convert into another, possibly dramatically different, form of life in one or at most two generations as a result of a “macromutation.” One of the most prominent proponents of this theory, the geneticist
Goldschmidt (1940), pointed out that such a macromutation would likely produce unviable “monsters” but that
“hopeful monsters” would occasionally occur, i.e., phenotypes well adapted to a novel environment. In this

manner, a completely new kind of organism (or entire lineage) might evolve without benefit of natural selection. This concept was refuted when it became clear that organisms are not types (such as glucose molecules) and that populations consist of numerous genomic variants.
As such, a single hopeful monster might survive and be well adapted, but it could never contribute to evolution unless another hopeful monster of the other sex appeared with which it could reproduce and contribute progeny to the next generation. Although “macromutations,” as postulated by transmutationists, have rarely been observed, recent studies indicate that certain mutations with large phenotypic effects may have been of importance in the course of invertebrate evolution (Ronshaugen et al.
2002). However, the original “hopeful monster” theory, as envisioned by Goldschmidt (1940) and others, is not supported by experimental evidence (Mayr 2001). In any event, the real issue is not whether “hopeful monsters” have played some role in organic evolution but whether they represent the most frequent mode whereby radical evolutionary changes occur.

The evolutionary synthesis
Reif et al. (2000) point out that the “evolutionary synthesis” was a historical process that occurred between ca.
1930 and 1950. This intellectual long-term project, carried out by numerous biologists in several countries, finally led to a “product,” a list of consensus statements that form the core of the synthetic (or modern) theory of biological evolution.
According to most historians of biology, the basic tenets of the synthetic theory are essentially based on the contents of six books authored by the Russian/American naturalist/geneticist Theodosius Dobzhansky (1900–
1975), the German/American naturalist/systematist Ernst
Mayr (born 1904), the British zoologist Julian Huxley
(1887–1975), the American paleontologist George G.
Simpson (1902–1984), the German zoologist Bernhard
Rensch (1900–1990), and the American botanist G.
Ledyard Stebbins (1906–2000). These books (Dobzhansky 1937 Mayr 1942 Huxley 1942 Simpson 1944
Rensch 1947 Stebbins 1950) were written by the six most important “architects” of the synthetic theory (see Fig. 8).
A detailed historiographical reanalysis reveals that, in addition to Dobzhansky, Mayr, Huxley, Simpson, Rensch, and Stebbins, other biologists made significant contributions (Reif et al. 2000 Junker and Hoßfeld 2001 Junker
2004). However, a detailed discussion of these contributions is well beyond the scope of this article.
Mayr (1982, 1988) described in detail how most of the non-Darwinian theories of evolution were refuted between ca. 1930 and 1950 either by theoretical arguments
(populational versus typological thinking) or by observations/experiments. Nevertheless, no consensus as to the mechanisms of evolution emerged among the leading evolutionists of that decade (Fisher 1930). Indeed, two major camps of biologists were established camps that

persist to the present day: geneticists and mathematical modelers who study evolutionary processes with selected organisms in the laboratory and naturalists (taxonomists, paleontologists) who draw conclusions based on studies of populations of organisms observed (or preserved) under natural conditions. In this respect, the reductionist approach of geneticists defines evolution as “irreversible changes of the genetic composition of populations” and concentrates on the genotypic level of organismic organization. In contrast, naturalists define evolution as “gradual descent with modification (inclusive of the diversification of species)” and concentrate on the phenotype. In accordance with Mayr (1963, 1988, 2001), we agree that the entire organism is the target of selection and view the reductionist definition of evolution emerging from a strictly genomic perspective as far too narrow. Certainly, irreversible genomic changes are required for evolution to occur, but these changes must be fixed and sustained in populations by means of natural selection, which acts at the level of the phenotypic alterations these genomic changes evoke. Accordingly, in the following sections, we emphasize the process of phenotypic evolution, which is the visible outcome of changes in gene frequencies in large populations.
The first book authored by Dobzhansky (1937), who later coined the famous phrase “nothing in biology makes sense except in the light of evolution,” was the cornerstone of the synthetic theory. While still in Russia,
Dobzhansky worked as a naturalist/taxonomist. After emigration to the USA in 1927, he worked for many years in the laboratory of T.H. Morgan, developing the skills and knowledge of an experimental geneticist. Importantly,
Dobzhansky was the “catalyst” who brought together the two camps. The results of this consensus among reductionist geneticists and the naturalists/taxonomists are described in detail below.

The synthetic theory: basic tenets
The terms “evolutionary synthesis” and “synthetic theory” were coined with the title of J. Huxley’s (1942) book
Evolution: the Modern Synthesis wherein the term “evolutionary biology” instead of the phrase “study of evolution” was first introduced. Some years later, Huxley pointed out that one of the major events in the history of science was the emergence and establishment of evolutionary biology as a separate branch of the biological sciences (Smocovitis 1996 Ruse 1996). Indeed, Huxley was the first to stress that “evolution may lay claim to be considered the most central and the most important of the problems of biology. For an attack upon it we need facts and methods from every branch of the science – ecology, genetics, paleontology, geographical distribution, embryology, systematics, comparative anatomy – not to mention reinforcements from other disciplines such as geology, geography and mathematics” (Huxley 1942, p. 13).
In the same vein, G.G. Simpson, another founder of the modern theory, said “The synthetic theory has no Darwin,

being in its nature the work of many different hands. To mention any of these is to be culpable of important omissions [. ]. The theory has often been called neoDarwinian [. ]. The term is, however, a misnomer and doubly confusing in this application. The full-blown theory is quite different from Darwin’s and has drawn its materials from a variety of sources largely non-Darwinian and partly anti-Darwinian. Even natural selection in this theory has a sense distinctly different, although largely developed from, the Darwinian concept of natural selection” (Simpson 1949, pp. 277–278).
What were the basic conclusions drawn by the
“architects” of the modern theory? Ernst Mayr provides the following summary: “1. Gradual evolution can be explained in terms of small genetic changes (“mutations”) and recombination, and the ordering of this genetic variation by natural selection 2. the observed evolutionary phenomena, particularly macroevolutionary processes and speciation, can be explained in a manner that is consistent with the known genetic mechanisms” (Mayr and Provine 1980, p. 1). A more detailed list is as follows:
1. The units of evolution are populations of organisms and not types. This mode of thinking led to the biological species concept developed by Mayr (1942) who more recently defined the biospecies as “an interbreeding community of populations that is reproductively isolated from other such communities”
(Mayr 1992 Beurton 2002). This species concept can not be applied to microorganisms, which reproduce asexually by binary fission (see Fig. 4).
2. Genetic and phenotypic variability in plant and animal populations is brought about by genetic recombination
(reshuffling of chromosome segments) resulting from sexual reproduction and random mutations along the parent–offspring sequence. In contrast to animals, plants lack a germ-line. The amount of genetic variation that a population of sexually reproducing organisms can produce is enormous. Consider a single parent with N number of genes, each with only two alleles. This individual can produce 2N genetically different sperm or egg cells. Because sexual reproduction involves two parents, each set can therefore produce an offspring with one of 4N different genotypes. Thus, if each parent genotype has a mere 150 genes with two alleles each (a gross underestimate of the human genome), each parent can give rise to over
1045 genetically different sperm or egg cells, and a single set of parents can produce more than 1090 genetically different offspring (a number that comes very close to estimates of the total number of particles in the observable universe).
3. Natural selection is the most important force that shapes the course of phenotypic evolution. In changing environments, directional selection is of special importance, because it causes a shift in the population mean towards a novel phenotype that is better adapted to altered environmental conditions. Additionally, in

the pioneers of evolutionary biology (Darwin, Wallace,
Weismann) and the “architects” of the synthetic theory
(Dobzhansky, Mayr, Huxley and others). The expansion of our modern picture of the mechanisms of evolution is discussed in the following sections, which deal with topics summarized in Fig. 8.

Paleobiology and rates of evolution

Fig. 5 Scheme to illustrate the interaction of the basic processes that bring about phenotypic evolution in a variable population of organisms (animals or plants) (adapted from Stebbins 1971)

small populations, random genetic drift (loss of genes from the gene pool) may be significant.
4. Speciation can be defined as a “step of the evolutionary process (at which) forms . become incapable of interbreeding” (Dobzhansky 1937, p. 312). A number of pre- and post-mating isolation mechanisms have been proposed. Geographic isolation of founder populations is believed to be responsible for the origin of new species on islands and other isolated habitats.
Allopatric speciation (divergent evolution of populations that are geographically isolated from each other) likely accounts for the origin of many animal species
(Mayr 1942, 1963 Mayr and Diamond 2001). However, sympatric speciation (the occurrence of new species without geographic isolation) is also documented in many taxa, notably higher plants, insects, fishes, and birds (Howard and Berlocher 1998).
5. The evolutionary transitions in these populations are usually gradual, i.e., new species evolve from preexisting varieties by slow processes and maintain at each stage their specific adaptation. There are some exceptions to this general rule that are discussed below. Immigration of individuals from neighboring populations cannot be ignored, but this process is of lesser importance.
6. Macroevolution (i.e., phylogenetic developments above the species level or the occurrence of higher taxa) is a gradual step-by-step-process that is nothing but an extrapolation of microevolution (origin of races, varieties, and species).
It is difficult to depict these six points in order to illustrate the basic processes that bring about phenotypic evolution. Stebbins (1971) was the only “architect” who published a model of the basic tenets of the synthetic theory. A modified version of this classical scheme is shown in Fig. 5.
Carroll (1997, 2000, 2002), Fleagle (2001), and Gould
(2002) point out that the patterns and controlling forces of evolution are much more varied than were postulated by

The biological species concept – an integral part of the synthetic theory – cannot be applied directly to the fossil record. Nevertheless, a population-based concept does lie behind the systematic study of fossilized organisms.
Paleontologists have adopted the morphological species concept, which is also used by the majority of systematists of extant organisms (Benton and Pearson 2001).
In 1944, when Simpson’s book Tempo and Mode in
Evolution was published, no fossils from the Precambrian period (before 550 mya) and only a few examples of intermediate morphological sequences linking ancestral with derived forms of fossil organisms were described.
Today, we know that the earliest prokaryotic microbes inhabited the Earth 3,500 mya (Fig. 2). We also know of numerous “missing links” preserved in the vertebrate fossil record (Table 2). For example, the evolutionary history of several extinct groups of organisms, such as the dinosaurs, has been reconstructed in remarkable detail
(Sereno 1999). On the basis of these studies, it is now well established that flying birds evolved from a group of bipedal dinosaurs, four-winged arboreal reptiles that could possibly glide (Wellnhofer 2002 Xu et al. 2003).
This conclusion is further supported by the finding that crocodiles are the closest living relatives of birds and that these two taxa represent the only surviving lineages of the
Archosauria (Meyer and Zardoya 2003). The origin of the vertebrate class Mammalia has also been reconstructed on the basis of large collections of fossils such as mammallike reptiles (synapsids). According to Kemp (1999) it is by far the best-represented transition of all in the fossil record at the general taxonomic level (Table 2). The perception that intermediate forms in the fossil record are generally absent had an important effect on the thinking of those credited with constructing the modern synthesis.
In his book Variation and Evolution in Plants (1950),
Stebbins complained about the failure of the fossil record to contribute to our understanding of the phylogenetic development of the early angiosperms. Indeed, Darwin
(1859) called the origin of the angiosperms an “abominable mystery.” Nevertheless, this gap in our knowledge is slowly but surely being filled with new information, even for seed plants, e.g., the discovery of the 125-Mayear-old early angiosperm Archaefructus (Sun et al.
2002). As a result of these and many other advances, paleontology (originally a branch of geology) has developed into the discipline now called paleobiology (Schopf
1999 Briggs and Crowther 1990 Benton 1997 Benton and Harper 1997 Carroll 1997 Niklas 1997 Cowen

Table 3 Estimates of mean species durations for a variety of fossil groups of organisms. These longevities are based on the application of the morphological species concept

Marine bivalves and gastropods
Benthic and planktonic foraminifers
Marine diatoms
Trilobites (extinct)
Ammonites (extinct)
Freshwater fishes
Higher plants: herbs
Shrubs, hardwoods
Conifers, cycads

Data from Stanley (1985), Niklas (1997), Levin (2000)

Other insights are coming from studies of polyploidy.
Stebbins devoted two chapters to the occurrence of more than two genomes per cell and speculated on its role in plant evolution (Stebbins 1950). Today we know that about 50% of all angiosperm species are polyploids and that duplicated genes (genomes) can undergo functional divergence and thus acquire new functions. Indeed, polyploidy may confer ecological benefits that are responsible for the success of many angiosperm species
(Soltis and Soltis 2000).
Botanists speculated that sympatric speciation is as important as allopatric speciation (Stebbins 1950), but zoologists tended to ignore this mode of speciation, perhaps because of the emphasis on Mayr’s (1942) biological species concept and the role of geographic isolation. Nevertheless, recent studies have shown that genetic divergence can and does occur in sympatric populations. Hence, zoologists, who have been the principal architects of the modern evolutionary theory, have tended to ignore the insights gained from the study of plants until they could see evidence for these phenomena in animals.
In his classic book, Simpson (1944) recognized that the rates of evolution are highly variable in different groups of fossil organisms. More recent quantitative studies have revealed that the (morpho)-species durations in the fossil record are much larger than originally anticipated: from
1–2 Ma in mammals to >20 Ma in bryophytes, conifers, and some marine invertebrates (Table 3). These data show that a species, once evolved and thereafter the occupant of a defined ecological niche, may remain stable over hundreds of thousands of generations. However, examples of more rapid speciation events are well documented. In cichlid fishes (Meyer et al. 1990, Meyer 1993), polyploid angiosperms (Soltis and Soltis 2000), and Southern
African ice plants (Klak et al. 2004), reproductive isolation and the resulting (sympatric) origin of novel species can occur within a few hundred (or thousand) generations.
Nevertheless, the typical morphospecies undergoes little measurable change in form during more than a million

years (Stanley 1979, 1985 Niklas 1997 Kemp 1999
Levin 2000).
The number of populations of organisms in a particular area is largely determined by the rates of speciation and extinction: the difference represents our extant biodiversity (Niklas 1997). In spite of the fact that the modes of speciation are a key issue in evolutionary biology, there is still debate about the “creative process” that leads to species diversity. Theories of speciation in sexually reproducing organisms are summarized by Howard and
Berlocher (1998), Schilthuizen (2001), and Schluter

Mass extinctions and species selection
Darwin (1859, 1872) discussed not only the origin, but also the decline and demise of species. As a major cause of the extinction of populations and entire species, he proposed interspecific competition due to limited resources (Table 1): over evolutionary time, superior species were envisioned to replace less well-adapted ones
(Raup 1994). This perspective has changed in recent years with a greater understanding of the roles of mass extinctions, episodes in Earth’s history where the “rules of natural selection and adaptation” appear to have been abandoned. This perspective was presaged in Mayr’s (1963) first major book of the post-synthesis period wherein he points out that extinction must be considered as one of the most conspicuous evolutionary phenomena. Mayr discussed the causes of extinction events and proposed that new (or newly invading) diseases or changes in the biotic environment may be responsible. In addition, he wrote: “The actual causes of the extinction of any fossil species will presumably always remain uncertain. It is certain, however, that any major epidemic of extinction is always correlated with a major environmental upheaval” (Mayr
1963, p. 620).
This hypothesis, largely unsupported by facts when proposed 40 years ago, has since gained considerable support. The term “mass extinction,” mentioned by Mayr
(1963, p. 617), but not further defined, is used when many species become extinct within a short time the events are related to a single cause (or combination of causes) and the extinct species include plants and animals of all body sizes, marine, and non-marine forms (Benton and Harper
1997). Although most species die out during periods of so-called “background extinction,” at least five mass extinctions are generally recognized: Late Ordovician,
Late Devonian, Permian-Triassic (P-T), Late Triassic, and
Cretaceous-Tertiary (K-T) at ca. 450, 364, 250, 200, and
65 mya (Raup 1994 Benton 1997 Hallam and Wignall
1997). The two most severe mass extinctions (P-T and
K-T see Fig. 2) warrant particular comment.
The biological extinction that occurred at the P-T boundary about 250 mya represents the most severe extinction event in the past 550 million years (Ma). It is estimated that about 70% of vertebrate families on land,

many woody gymnosperms, and more than 90% of species in the oceans were killed. Several causes for this
“mother of all extinctions” have been proposed, including volcanism, an asteroid or comet impact, oceanic anoxia, and environmental change (Hallam and Wignall 1997). It is now known that at the end of the Paleozoic (Permian), the supercontinent of Pangea formed this geological event was associated with the eruption of the Siberian flood basalts, 250 mya. These giant volcanic eruptions, confined to a time interval of only a few hundred thousand years, were probably the major cause for the catastrophe in the late Permian biosphere (Jin et al. 2000
Benton and Twitchett 2003), since evidence in support of a large extraterrestrial impact during the P-T extinction is problematic (Benton and Twitchett 2003 see also Jin et al. 2000).
The K-T boundary records the second largest massextinction event: this global catastrophe wiped out 70% of all species, among which the dinosaurs are the best known
(Sereno 1999). Small mammals survived to inherit vacated ecological niches, enabling the rise and adaptive radiation of the lineages that ultimately evolved into
Homo sapiens (Benton 1997). Paleontologists have proposed numerous hypotheses to account for the “dinosaur murder mystery.” Two theories have survived – volcanic upheaval and asteroid collision.
The Deccan traps in India are layered flows of basaltic lava laid down at the K-T boundary (68–64 mya). These rock layers suggest that a global volcanic catastrophe may have occurred and been the driving force behind the K-T
(and the earlier P-T) extinction event (Benton 1997).
According to the more popular second scenario, a giant
10-km asteroid (or comet) struck Earth at a velocity of at least 10 km/s. The incredible energy liberated by this collision would have caused a global environmental disaster resulting from fire, acid rain, tsunamis, storm, and cold and darkness followed by greenhouse warming
(Alvarez 1997). Evidence supporting this “Alvarez extinction event” (Mayr 2001) is compelling and includes the K-T-iridium anomaly, impact tracers such as shocked quartz, and the discovery of the 65-Ma-old 180 km subsurface Chicxulub crater in Yucatan, Mexico (Alvarez
1997). Regardless of the cause, many different animals suffered during the K-T extinction event (Benton 1997).
The effect on land plants is more controversial (for contrasting ideas, see Niklas 1997 Wilf et al. 2003).
In summary, the “environmental upheaval hypothesis” of Mayr (1963) has been confirmed. Although much of evolutionary history may be gradual, occasional catastrophic events have punctuated its steady (background) pace. It is obvious that the few “lucky survivors” determined subsequent historical patterns in the history of life. Macroevolution and punctuated equilibrium
Darwin (1859, 1872) introduced the concept of gradualism: higher taxa (and hence novel body plans) are the

products of accumulated small differences over extended evolutionary time (Table 1). Mayr (1942, p. 298) concluded that “all available evidence indicates that the origin of the higher categories is a process which is nothing but an extrapolation of speciation. All the processes of macroevolution and the origin of higher categories can be traced back to intraspecific variation even though the first steps of such processes are usually very minute.”
Two decades later, the same author reinforced this viewpoint: “The proponents of the synthetic theory maintain that all evolution is due to the accumulation of small genetic changes, guided by natural selection, and that transspecific evolution is nothing but an extrapolation and magnification of the events that take place within populations and species . essentially the same genetic and selective factors are responsible for evolutionary changes on the specific and on the transspecific levels . it is misleading to make a distinction between the causes of micro- and macroevolution” (Mayr 1963, pp. 586–587).
Stebbins (1971, p. 161) came to the same conclusion:
“. the evolution of higher categories has been by means of the same processes which have brought about the evolution of races and species.”
In spite of the consensus among the “architects” of the synthetic theory, the extent to which macroevolution is the product of microevolutionary modifications is still debated (Stanley 1979 Erwin 2000 Simons 2002). In general, a continuity between micro- and macroevolution is documented in many fossil lineages available today.
The results summarized in Table 2 show that the fossil record of vertebrates includes forms intermediate between fishes and amphibians, between amphibians and land vertebrates (reptiles), between reptiles and mammals, and between reptiles (theropod dinosaurs) and birds. It is obvious that millions of years ago the characteristics that currently distinguish these five classes of vertebrates were not yet established.
Another striking example of “macroevolution in progress” is seen among the grasses (Poaceae), which display C3 and C4 pathways of photosynthesis (Kellogg
2000). The C4 mode of CO2-assimilation evolved from the basal C3-mechanism, which is retained in 90% of all extant flowering plants. Numerous C3–C4 intermediate forms have been described in a variety of taxa. The evolutionary intermediacy of C3–C4 plants has been documented by several lines of evidence, including gas exchange measurements (Sage and Monson 1999). The pattern of macrofossils shows that the earliest grasses (C3) appear in the Eocene (about 55 mya), whereas the earliest
C4 macrofossils are dated at 12.5 mya (Kellogg 2000).
These data demonstrate that C4 plants evolved from C3 forms. This macroevolutionary process can be reconstructed and experimentally analyzed in terms of the many C3–C4 intermediates (Sage and Monson 1999
Kellogg 2000 Schütze et al. 2003).
Taken together, these examples accord well with the basic tenet of the synthetic theory that continua exist between small-scale allele frequency changes in popula-

tions and large-scale phylogenetic changes leading to novel body plans (Simons 2002).
However, evolutionists acknowledge that exceptions exist. One example is the origin of eukaryotic cells from prokaryotic ancestors by means of endosymbiosis (see
Fig. 2). Another is proposed by Ronshaugen et al. (2002) who provide experimental evidence suggesting that the divergence of six-legged insects from crustacean-like arthropod ancestors with multiple limbs (about 400 mya) may have occurred within a relatively short time period.
These two examples are not easily reducible to the gradualistic mechanisms treated by the architects of the modern synthesis, although macroevolutionary alterations in body plans by means of many small evolutionary steps can occur rapidly when viewed in the perspective of geological time scales (Mayr 1942, 1963 Niklas 1997).
The “punctuated equilibrium” theory of Gould and
Eldredge (1993) was originally proposed as a alternative to Darwin’s concept of gradualism. According to this theory, evolution tends to be characterized by long periods of morphological stasis (“equilibrium”), “punctuated” by episodes of rapid phenotypic change. The evidence in support of this model, which is the opposite of a continuous anagenetic transformation of populations or
“phyogenetic gradualism,” was recently summarized by
Gould (2002). Over the past decades, numerous studies have shown that evolutionary transitions are gradual, although the rates of phylogenetic developments may vary. It follows that evolution is both gradual and occasionally more or less “punctuated” (Kellogg 2000
Mayr 2001 Bokma 2002). At any rate, the conflict between the gradualist and punctualist interpretation of the fossil record is no longer an issue, i.e., evolutionary rates can and do vary, often appreciably (Table 3). The real issue is whether “rapid” evolution as gauged by geological time scales is evidence for the absence of microevolutionary modifications of genomes as gauged by reproductive time scales. Although the debate lingers on, the evidence that the mechanisms underlying macroevolution differ from those of microevolution is weak at best. Weismanns hypothesis
The theory for the inheritance of acquired characteristics advanced by Jean-Baptiste de Lamarck (1744–1829) and accepted by Darwin (1859, 1872) was strenuously opposed by August Weismann (1834–1914). This eminent zoologist/cytologist was an ardent proponent of natural selection, so much so that he has been recognized as second only to Darwin in his profound affect on evolutionary theory (Mayr 1988) (see Fig. 1). In a classic experiment, Weismann cut off the tails of successive generations of mice and showed that the tail length of the progeny of each generation was the same as that of the preceding generations. Additionally, Weismann absolutely rejected any brand of Lamarckian “soft inheritance” based on his detailed cytological studies that indicated

that the reproductive cells giving rise to the gametes
(sperm and egg cells) in animals segregate early in development from non-reproductive cells such that they cannot be influenced by alterations of non-reproductive tissues or organs (the concept of the germ-line). Weismann (1892) proposed the word “germplasm” for reproductive cells (specifically their chromosomes) and the term “soma” for non-reproductive cells (and their chromosomes) and, as early as 1889, he argued that sexual reproduction provided the variability in populations required for adaptive evolution.
By the 1930s and 1940s, many other scientists performed experiments similar to Weismann’s mouse-tail studies and the notion of “soft inheritance” was discarded forever. Mendelian genetics had developed by that time to provide a firm basis to explain the variation among individuals in a population required by Darwin’s theory.
Since 1960 molecular genetics has demonstrated that changes in the base-pair composition of DNA are translated into changes in protein structure or developmental regulations and that no change in a protein or other cellular constituents other than nucleic acids can alter the information encoded in DNA. Thus, the “hard inheritance” postulated by Weismann has been demonstrated as a fact.
The term “Weismann’s hypothesis” now stands for the explicit proposal that sexual reproduction functions to provide variation for natural selection to act upon (Mayr
1982 Burt 2000). Nevertheless, the adaptive significance of sex (and why sexual reproduction evolved) has remained a matter of considerable debate because of the
50% “fitness cost” of meiosis which, in theory, should favor asexual reproduction (Niklas 1997). Note that during sexual reproduction, each parent contributes only
50% of its genome to its offspring. The resulting genomic variation thus introduced into a population can lead to maladapted individuals. In contrast, asexual reproduction ensures that new individuals are as adapted to their environment as their parents, since every individual in the population leaves progeny that are clones of itself. So why does bisexual reproduction abound?
According to Mayr (1982) the 50% “fitness cost” of sexual reproduction can be resolved if we consider the fact that environments are constantly changing, whereas
Niklas (1997) has pointed out that sexual and asexual reproduction are not mutually exclusive, especially for plants. The variable offspring produced by sexual reproduction may include some individuals better suited to new environmental conditions, whereas asexually propagated individuals remain adapted to past environmental conditions. Likewise, Hamilton et al. (1990) proposed that the genetic variability that sexual reproduction provides allows plants and animals to cope with parasites and diseases. In an evolutionary “arms race,” pathogenic organisms can grow and adapt so rapidly that they can circumvent the host’s defenses. More recently, Rice and
Chippindale (2001) have provided evidence that sexual reproduction is advantageous because it accelerates phenotypic evolution by allowing beneficial mutations

to spread without being held back by the baggage of deleterious mutations at other loci in the genome. All these ideas and experiments support Weismann’s original concept (1892) that sexual reproduction produces variable progeny and thereby promotes adaptive evolution.

Sexual selection and altruism
Darwin (1859) introduced the concept of sexual selection.
In his book The Descent of Man (1871) he described numerous examples, e.g., the peacock’s tail and the lion’s mane. Darwin argued that competition among males resulted in the selection for traits that increased the mating success of competing males, traits that could nevertheless decrease the chances of survival of the individual. Darwin argued that “competition” could take one of two forms, either physical combat among males or competition for the attention of females. Large body size and musculature provide advantages in male combat, whereas traits such as colorful male plumage and complex display behavior increase the attention of females (“female choice”). Darwin’s (1871) ideas were not widely accepted (Andersson 1994) and the proponents of the synthetic theory (Dobzhansky 1937 Mayr 1942 Huxley
1942) largely ignored the concept of female choice. The study of sexual selection only gained momentum in the post-synthesis era.
Dawkins (2002) argued that A.R. Wallace (and not
Darwin) first proposed that males with bright plumage demonstrate their health and high-quality as a sexual partner. According to this “good-genes sexual selection hypothesis,” female mate choice affords an evolutionary advantage. This perspective has received empirical support. Møller and Alatalo (1999) report a correlation, albeit small, between offspring survival and male secondary sexual characters across a large number of taxa (birds, amphibians, fish, insects). Additionally, experiments with blackbirds indicate that males with the brightest bills have a strong immune system (Pennisi 2003). Thus female choice may foster the general health of blackbird populations. These and other data are consistent with the concept that female choice influences the traits of males and may even be beneficial to males in ways that have nothing to do directly with mating success.
Models of both sympatric and allopatric animal populations also indicate that sexual selection has the potential to drive rapid divergence and hence may generate reproductive isolation (Panhuis et al. 2001).
Studies of the explosive diversification of cichlid fishes in the three Great Lakes of East Africa indicate that sympatric speciation may have been a major driving force during this adaptive radiation (Meyer 1993 Schluter
2001). Clearly, however, more information on the role of sexual selection during speciation is required (Panhuis et al. 2001).
Since the publication of the Origin of Species (Darwin
1859), generations of anti-evolutionists have argued that altruistic behavior (self-denying acts performed for the

benefit of others) is incompatible with the principle of natural selection. Nonetheless, altruistic behavior, such as parental care and mutualism, has been observed and documented throughout the animal kingdom, from lower invertebrates to mammals (Krebs and Davies 1993
Kutschera and Wirtz 2001 Trillmich and Diesel 2002
Clutton-Brock 2002). One of the more conspicuous forms of altruism occurs in certain social insects, such as ants, bees and wasps, that have a sterile worker class.
In a classic paper, Hamilton (1972) asked “in what sense can a self-sacrificing sterile ant be considered to struggle for existence or to endeavor to maximize the numbers of its descendants?” This question – the evolution of eusociality in insects and the occurrence of worker altruism (Hölldobler and Wilson 1990) – has been answered by the theory of inclusive fitness or kin selection (Hamilton 1972). According to the Darwin/
Wallace principle, natural selection refers to individual differences in reproductive success (RS), where RS is the number of surviving offspring produced during an individual’s lifetime. Hamilton (1972) enlarged on this idea and included RS effects on the relatives of the individual: the term inclusive fitness refers to RS plus the RS of relatives, each devalued by the corresponding degree of relatedness (Hölldobler and Wilson 1990). Numerous studies of a variety of animal species have shown that altruism is not in conflict with evolutionary theory.
However, a modification and expansion of our view of a single organism in a population was necessary: the individual no longer seems to have a unitary self-interest, but is part of a complex parent–relative network. For a critical discussion of this subject the reader is referred to
Hölldobler and Wilson (1990), Krebs and Davies (1993),
Griffin and West (2002), Clutton-Brock (2002), and Jost

Endosymbiosis and eukaryotic cell evolution
The evolution of the first eukaryotic cells from their prokaryotic antecedent condition has received considerable attention (Martin et al. 2001 Martin and Borst 2003).
This key event in the history of life occurred about 2,000–
1,500 mya during the early Proterozoic (Fig. 2). Two nonmutually exclusive hypotheses have been advanced to explain the origin of eukaryotes: endosymbiosis and autogenesis. The endosymbiotic hypothesis (also called a theory) envisions the evolution of the first eukaryotic cells to have resulted from the permanent incorporation of once autonomous, physiologically different prokaryotic cells within a host prokaryotic cell-type. According to this concept, mitochondria evolved from some form of ancient aerobic bacteria, whereas chloroplasts evolved from some form of cyanobacteria-like prokaryote. Once these residents gained permanent residency in their host cell, they continued to function and replicated such that derivative confederations were produced when the host cell underwent binary fission (Margulis 1993). In contrast, the autogenous hypothesis argues that the mitochondria and

chloroplasts (as well as other eukaryotic organelles and structures such as the endoplasmic reticulum) evolved as a consequence of selection pressures for physiological specialization within an ancient prokaryotic cell-type.
According to this hypothesis, the host cell membrane invaginated to encapsulate internal physiologically different portions of the ancestral cell-type. Over evolutionary time, these membrane-bound regions became increasingly specialized and evolved into the various organelles that currently define the stereotypical eukaryotic cell.
The endosymbiotic hypothesis is supported by the fact that mitochondria and chloroplasts are double membranebound, reproduce like prokaryotes by binary fission
(Fig. 4), have circular DNA, and are sensitive to bacteriocidal substances (Martin et al. 2001). Additionally, the oligonucleotide sequences of living cyanobacteria closely align with those of modern-day cyanobacteria, whereas those of mitochondria align well with the oligonucleotide sequences of the proteobacteria (a group of purple nonsulfur bacteria) (Schopf 1999 Pace 2001). The evidence for the autogenous hypothesis is less convincing (Niklas
1997). However, the endosymbiotic hypothesis does not easily account for single membrane-bound organelles, the evolution of the endoplasmic reticulum, or the appearance of single membrane-bound organelle-like structures in prokaryotic cells. Nor does the endosymbiotic hypothesis directly address the origin of the nucleus, which is itself a double membrane-bound structure. In this regard, it is notable that both models speculate that the host cell-type, which was presumably either some form of an anaerobicaerotolerant prokaryote or an inefficient aerobic prokaryote, had the capacity for some form of endocytosis, i.e., the ability to invaginate its outer cell membrane, either for engulfing prokaryotic cells (according to the endosymbiotic theory) or encapsulating internally physiological regions of the host cell (according to the autogenous hypothesis). Curiously, the outer cell membrane of modern-day bacteria is remarkably inflexible and generally lacks the ability to form closed vescicles. Whether this feature characterized the most ancient forms of bacterial life, however, is unknown.
The evolution of the first eukaryotic cells cannot be divorced from the phylogenetic development of mitotic and meiotic cell division (and thus the evolution of sexual reproduction). Limited space precludes a detailed discussion of these features of eukaryotic evolution. Cogent discussions of this topic can be found in a number of books and papers (e.g., Margulis 1993 Margulis and
Schwarz 1998 Martin et al. 2001 Martin and Borst 2003
Martin and Russell 2003).

Evo-devo and Hox genes
Historians of science have long noted that one major discipline, developmental biology (formerly called embryology), was not part of the evolutionary synthesis, although this branch of biology was discussed in detail by
Darwin (1859, 1872). In his essay, Mayr (1993) describes

the anti-evolution sentiments of several embryologists of the synthesis-period and noted that “The representatives of some biological disciplines, for instance, developmental biology, bitterly resisted the synthesis. They were not left out of the synthesis, as some of them now claim, but they simply did not want to join”. Over the past two decades, however, developmental biology and evolutionary theory have united to form a new branch of biological enquiry called evolutionary–developmental biology or
“evo-devo” (Hall 1999), which explores how developmental processes evolve and how they ultimately obtained the various body plans of past and present-day organisms.
According to Arthur (2002), the single most important factor responsible for the synthesis of developmental biology and evolutionary theory was the discovery of a group of regulatory genes called the homeotic (Hox) gene family. These genes encode DNA-binding proteins (transcription factors) that profoundly influence embryonic development. For example, the suppression of abdominal limbs in insects is determined by functional changes in a protein called Ultrabithorax, which is encoded by a Hox gene (Ronshaugen et al. 2002). Importantly, the Hox family of genes has been identified in arthropods (insects, crustaceans, chelicerates, myriapods), chordates (fishes, amphibians, reptiles, birds, mammals), and has analogs among plant and yeast species. On the basis of comparative gene analyses in several taxa, the evolution of the
Hox-gene clusters in vertebrates has been reconstructed.
Although the common ancestor of mouse and human lived around 75 mya, the architectures of their Hox-gene clusters are identical (Meyer 1998). Therefore, the Hox gene family is extremely ancient and apparently highly conserved, which has profound implications for the evolution of developmental processes and patterns. For a detailed discussion of some recent evo-devo studies, see
Meyer (1998), Hall (1999), Schierwater and DeSalle
(2001), Arthur (2002), and Gilbert (2003).

Phenotypic plasticity
Natural selection does not act directly on the genotype. It acts on the phenotype, which if well adapted to its environment survives, reproduces, and passes some of its genomic components on to the next generation. In this sense, the phenotype can be viewed as a tactical expression of the strategy of its genotype. One such strategy is for the genotype to produce a range of phenotypic expressions, each of which is suited to a particular environmental circumstance. Indeed, for many organisms, the same genotype can give rise to many different phenotypic variants whose appearance or behavior depends on (or is at least correlated with) its environmental setting.
This phenotypic variation or “plasticity” (which is a measure of an organism’s norm of reaction) dictates the range of habitats that a particular genotype can occupy. In theory, a genotype that engenders a high degree of phenotypic plasticity has an improved chance of being passed on to the next generation, provided that the

“plasticity” enhances the functional performance of the phenotype (Niklas 1997 Pigliucci 2001).
Arguably, plant development is more “plastic” than that of most animals. Well known examples of plant plasticity are the differences in the size, shape, thickness, and anatomy of sun and shade leaves produced by the same tree as well as the differences in the form and anatomy of submerged versus aerial leaves on many aquatic plants (Bradshaw 1965 Sultan 2000). An explanation for the contrast in the degree to which plants and animals exhibit phenotypic plasticity may lie in the fact that plant development is typically indeterminate (i.e., the individual continues to grow indefinitely in size), metameric (e.g., the same organ types are continuously produced), and intimately tied to external physical cues (e.g., light quality and intensity). Likewise, most plants are sedentary organisms which begin and end their lives in very much the same location. Thus, the individual plant cannot leave its location when its environment becomes unfavorable and, regardless of its environmental circumstances, the development of new organs is dictated in part by their immediate environmental conditions (Niklas
1997, 2000a). Taken together, these features of plant life would appear to require a higher degree of phenotypic plasticity than might be expected from animals that can migrate as individuals to find suitable or favorable habitats. This perspective is supported by the observation that many forms of sedentary animals (e.g., sponges, corals, bryozoans) exhibit a higher degree of phenotypic plasticity than do animals capable of locomotion and migration. Epigenetic inheritance and molecular evolution
One major achievement of the evolutionary synthesis was the refutation of the Lamarckian concept of acquired inheritance (Mayr and Provine 1980). Recently, however, the Lamarckian perspective has re-emerged in the context of the study of epigenetics, that is, developmental processes that are promoted indirectly by a series of events that are not directly dictated by gene products. One example is the expansion of the vertebrate embryonic eye and brain, which is hydrostatically driven. The mechanics of eye and brain expansion is ultimately related to gene function, but the proximate causality is not. Another example is the methylation of certain regions of the genome, one form of gene “silencing” that is important in both plant and animal embryogenesis. Importantly, a variety of environmental factors, such as temperature, can influence the intensity of DNA methylation. These and other examples of epigenetic phenomena indicate that the nucleotide sequences sensu stricto are not the only heritable information (Kakutani 2002). However, these studies do not support Lamarck’s idea that morphological changes acquired during the lifetime of an animal can be transferred via the germ-line to the next generation.
Epigenetic phenomena are the emergent properties of the

genome and the response of the genome to its environment, both of which are heritable and mutable.
During the first years of the post-synthesis period, the discovery of the molecular structure of DNA and the publication of comparisons of amino acid sequences has given rise to the study of molecular evolutionary biology
(Page and Holmes 1998). In its broadest sense, this branch of biology examines the “archaeology” and structure of the genome of extant organisms in an effort to reconstruct phylogenetic relationships (molecular systematics)
(Meyer and Zardoya 2003 Schütze et al. 2003) and to elucidate the molecular basis of adaptation and speciation
(Golding and Dean 1998). Among the various insights that have emerged from molecular evolutionary biology is the recognition that many evolutionary novelties come from modifications (mutations) of regulatory as well as structural genes (Doebley and Lukens 1998). Likewise, gene duplication and divergence in function has been emphasized in treatments of the evolutionary appearance and divergence of the Bacteria, Archaea, and Eukarya
(Page and Holmes 1998) and the origin of novel functions
(neo-functionalization, see Zhang 2003). The concept that gene duplication can provide the raw material for evolution, which goes back to the 1930s, has received substantial support from numerous molecular studies (Zhang
2003). The molecular basis of phenotypic evolution has become one of the most important areas of study in the post-synthesis era. Although much has been learned over the past two decades, many basic questions nevertheless remain unanswered (Page and Holmes 1998 Zhang
For example, are the majority of phenotypic variants the result of selection or neutral genetic changes? According to the neutral theory of molecular evolution the majority of DNA (and protein) divergence between species is driven by random genetic drift and mutation, and not by positive natural selection (Futuyma 1998). The neutralist–selectionist debate is summarized by Page and
Holmes (1998), where a detailed treatment of this subject can be found. A recent analysis of genomic data indicates that positive selection is responsible for protein evolution in fruit flies and other species (Fay et al. 2002). These and other results are largely incompatible with the neutral theory and provide evidence for the occurrence of natural selection at the molecular level (Bell 1997 Kutschera

Experimental bacterial evolution
Despite their numerical abundance and their important roles in biogeochemical cycles, bacteria (Fig. 4) were largely ignored by the architects of the synthetic theory, which dealt with the evolutionary processes of bisexual eukaryotic macroorganisms (animals, plants). Today, the study of bacterial evolution is a burgeoning field that is contributing many insights into evolution as a whole.
The new field of experimental evolution with cultivated bacteria was exemplified by a classic paper by

Lenski and Travisano (1994) who described the propagation of 12 populations of E. coli B over 10,000 generations (1,500 days) in an identical test-tube environment. Each population was founded by a single cell from a strain that was unable to exchange DNA. It follows that spontaneous mutations were the only source of genetic variability in these populations. To mimic natural selection, a glucose-limited minimal medium was used.
Both cell size and relative fitness (measured in a competition experiment with the frozen–thawed ancestor) changed in this artificial system as a result of the successive fixation of several beneficial mutations (Elena et al. 1996). This experimental system revealed that punctuated evolution occurs in bacterial populations as a result of beneficial mutations followed by natural selection
(survival and propagation of those varieties that best cope with the low-sugar environment). Wahl and Gerrish
(2001) subsequently developed an integrated theoretical framework for the analysis of similar in vitro evolution experiments. This approach has now been used to study experimentally the evolution of strains of budding yeast, viruses, and self-replicating RNA-molecules (ribozymes)
(Schuster 2001 Joyce 2002).
In a recent review article, Elena and Lenski (2003) described the advantages of microorganisms for evolution experiments, methods for measurement of relative fitness of ancestral and evolved bacterial populations, and the genetic basis of evolutionary adaptations. In this excellent summary, the state of the art of experimental bacterial evolution is described and the relevance of in silico studies with “digital organisms” is stressed. This topic is discussed in the next section.

Computer simulations of phenotypic evolution
Recent developments in computer technology and mathematical principles have provided the tools with which to model organismic evolution. The approach has been to simulate all conceivable phenotypic variants for a particular lineage or grade of organic organization (i.e., to construct a “morphospace”) and to quantify the performance of each of these variants in terms of one or more biological functions believed to influence relative fitness, such as visual acuity in animals or photosynthesis in plants (i.e., to generate a “fitness landscape” sensu Sewall
Wright’s metaphor for adaptive evolution). This approach has been used in one of two ways: to quantify the number of species occupying different regions of the morphospace and thereby identify phenotypic regions that are well-adapted or maladaptive or to simulate “adaptive walks” in which the performance of the one or more biological tasks is increasingly maximized or optimized as morphological transformations are simulated by a computer. Clearly, this approach is purely heuristic in the sense that the results of computer simulations reflect the various assumptions used by a particular worker. Nevertheless, attempts to simulate the evolution of “digital organisms” can shed light on a number of historical trends

seen in the fossil record that would otherwise resist a quantitative description (Lenski et al. 2003).
For example, computer models have been used to mimic the early evolution of ancient vascular plants
(tracheophytes) (Niklas 1992, 1997, 1999, 2000a, 2000b).
These models have three components: (1) an N-dimensional domain of all mathematically conceivable ancient morphologies (the morphospace for ancient tracheophytes) (2) a numerical assessment of the ability (fitness) of each morphology to intercept light, maintain mechanical stability, conserve water, and produce and disperse spores and (3) an algorithm that searches the morphospace for successively more fit variants (an adaptive walk). Beginning with one of the most ancient plant forms
(Cooksonia, Early Devonian see Fig. 6A), tracheophyte evolution is simulated by locating neighboring morphologies that progressively perform one or more tasks more efficiently. The resulting “adaptive walks” indicate that early tracheophyte evolution likely involved optimizing the performance of many tasks simultaneously rather than maximizing the performance of one or only a few tasks individually, and that the requirement for optimization accelerated the tempo of morphological evolution in the
Mesozoic (from the Early Devonian to the late Carboniferous see Fig. 6A). A comparison of the fossil plants depicted in Fig. 6A that evolved over a period of 100 Ma and the “digital organisms” (Fig. 6B) reveals a striking similarity in form and design.
These simulations draw attention to the distinction between maximization and optimization and to the fact that natural selection acts on the phenotype as a whole and not on its individual parts (Mayr 2001). Every organism must perform a wide range of biological functions to grow, survive, and reproduce. No single function is more important than any other, because the phenotype is an integrated functional whole and because environmental factors influencing one or more parts of the phenotype indirectly or directly affect the whole organism. Importantly, different biological tasks have different phenotypic requirements and some tasks have antagonistic design requirements. Therefore, although it is possible to maximize the performance of one task, this maximization comes at some expense in terms of performing other tasks. In this respect, computer simulations of early vascular plants (Fig. 6B) indicate that the survival of an organism depends on resolving the performance of all biological tasks, which requires optimization rather than maximization. An additional insight from these simulations is that natural selection cannot create a “perfect” organism, because optimization results in organisms that perform all of their functional obligations reasonably well simultaneously but not perfectly in terms of each individual task. One result of optimization is that the number of phenotypes capable of optimizing the performance of their tasks is larger than the number of phenotypes capable of maximizing the performance of all other tasks.
The result of optimization, therefore, is a richer spectrum of phenotypic possibilities.

Fig. 6A, B Reconstruction of the evolution of land plants
(tracheophytes) based on the fossil record (A): Cooksonia,
Rhynia and Psilophyton from the Early Devonian (

400 Ma ago), Archaeopteris from the
Late Devonian (

350 Ma), Calamites and Lepidodendron from the Late Carboniferous

300 Ma ago). Computer simulation of early vascular land plant evolution (B). The virtual organisms were maximised for water conservation (S), mechnical stability (M), reproductive efficiency (R), and light interception (L) (stages 1–4). The fossils (A) and the digital plants
(B) are very similar. (Adapted from Niklas 1992, 2000b)

In his Origin of Species, Darwin wrote: “If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down” (Darwin 1859, p. 189). In this context, it was perfectly obvious that Darwin was thinking of the evolution of the eye, since he also wrote “that the eye, with all of its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection seems, I freely confess, absurd in the highest possible degree” (1859, p. 189). Darwin was well aware of the many difficulties revolving around a precise and detailed explanation for the evolution of the eye. Indeed, it is even argued by creationists today that no such explanation is possible, because the eye could not possibly be the result of natural selection. This misconception stems from two failures on the part of its advocates: first, the assumption that the evolution of the eye has to be explained by defining “the eye” purely typologically, and,

second, by ascribing the actual process of the evolution of the eye as an “accident.” Once these two misconceptions are removed, the evolution of “the eye” is easily explained as the result of a complex but completely understandable interaction between natural variation and selection. That “the eye” cannot be defined typologically is immediately obvious once we consider the multiple evolutionary origins of this organ broadly defined, e.g., the compound insect eye, the protozoan photoreceptor, the vertebrate lens eye (Oakley 2003). The failure of typological definitions in this case stems from the fact that “the eye” is an outstanding example of convergent evolution and thus is most profitably defined in terms of its function. When broadly defined functionally, “the eye” has evolved in many different animal lineages (e.g.,
Protista, Porifera, Ctenophora, Cnidaria, Platyhelminthes,
Annelida, Mollusca, Onychophora, Arthropoda, Echinodermata, Tunicata, and Vertebrata) (Salvini-Plawen and
Mayr 1977 Futuyma 1998 Oakley 2003).

Turning to its natural variation within each clade and the “accidental” (nonpredictable) nature of natural selection (Endler 1986 Grant and Grant 2002), detailed anatomical and morphological comparisons among individuals drawn from the same population indicate that this variation can be substantial, even among vertebrate species. Such natural variation, which is heritable, permits the operation of natural selection for each of the three major functions of “the eye” within individual lineages:
(1) light/shadow detection, (2) the detection of the direction of incident light (orientation), and (3) image formation. Likewise, partially or entirely complete sequences in the evolution of “the perfect eye” (e.g., from simple light-sensitive epithelial cells to such highly differentiated lenticular eyes as are found in the Gastropoda,
Cephalopoda, Insecta, or Vertebrata lineages) can be reconstructed because all of the various evolutionary stages are readily observed among extant members of these lineages and because some are preserved in the fossil record (Salvini-Plawen and Mayr 1977). An example, the evolution of complex lens eyes in aquatic snails, is depicted in Fig. 7A.
Likewise, computer simulations demonstrate that even with a pessimistic estimate of the amount of time required for heritable variation to obtain efficient eyes by means of the operation of natural selection is on the order of about
300,000 generations (Nilsson and Pelger 1994). These simulations (Fig. 7B) illustrate that the geologically rapid evolution of a lens with a mathematically ideal distribution of refractive index is possible in part because the proteins used to construct the lens are already present in ancestral forms. Since natural selection can operate on small random phenotypic variations, no distribution of refractive index is inaccessible mathematically. In summary, these studies (Fig. 7A, B) corroborate the fact that evolutionary novelties can arise as a result of “intensification in function” of a pre-existing structure. It should be noted that a second process, called “change in function”
(Mayr 1963), is documented in the fossil record (Table 2) and gave rise to new organs such as the wings of birds
(Wellnhofer 2002 Xu et al. 2003).

The major achievement of the modern synthesis (i.e., the unification of biology during the 1930–1950 period) was

Fig. 7 Reconstruction of the evolution of complex lens eyes in gastropods (snails) by comparison of eye anatomy in extant species
(A): eye cup (Patella), deeper cup (Pleurotomaria), pinhole eye
(Haliotis), closed eye (Turbo), lens eyes (Murex, Nucella). The shells of two species are shown (Patella, a sedentary algae feeder
Nucella, an agile predator). Computer-generated model sequence of the evolution of a simple pit eye (B). Initial stage (1): flat patch of light-sensitive cells sandwiched between a transparent protective layer and a second layer of dark pigment. Final stage (8): cameratype lens (L) eye with a geometry similar to that found in aquatic animals (snails, cephalopods, fish) (A: adapted from SalviniPlawen and Mayr 1977 B: adapted from Nilsson and Pelger 1994)

fragile relationship between religious belief and scientific enquiry. We do however draw attention to the fact that the challenge posed by creationism is serious because it jeopardizes our future as a species by virtue of rejecting science and its philosophical basis (methodological naturalism) at every level and across all disciplines. By so doing, it intrinsically rejects the benefits that science offers humanity. Scientists tend not to enter into public debates about creationism versus science, many of which are now taking place in local communities rather than in more general public forums (Pennock 2003 Gilbert 2003
Scott and Branch 2003). This reticence can have grave consequences. In our view, evolutionary biologists – indeed, all scientists – must step forward and educate the public about science in general and evolution in particular. We cannot afford to be shy or modest about what we have learned. It is our responsibility to advocate scientific thinking and to educate non-scientists.

Fig. 8 Scheme illustrating the expansion of the synthetic theory of biological evolution by integration of ten additional scientific disciplines. The list is not complete, i.e., the expanded synthesis is an open system composed of many sub-theories dealing with various aspects of the evolutionary process

the attainment of a broad consensus about the mechanisms that bring about evolutionary change. This general theory, which emerged from a neo-Darwinian perspective, was a major advance in the life sciences (Fig. 1).
And it continues to cast a bright light on what may be called the post-modern synthesis, one that continues to expand and elaborate our understanding of evolution as the result of the continuous and tireless exploration of virtually every branch of science, from paleobiology/ geology to natural history and cell/molecular biology
(Fig. 8). Indeed, the “evolution” of evolutionary theory remains as vibrant and robust today as it ever was.
It should be noted that evolutionary biology is no longer a purely academic discipline. It is now an essential part of the applied sciences. Bull and Wichman (2001) have summarized many socially relevant examples in which evolutionary principles and methods have been used to solve practical problems such as the creation of new drugs, industrial enzymes, the development of computer programs, or the management of bacterial resistance to prescribed antibiotics.
Sadly, the efforts and insights of those exploring the rich fabric of evolutionary biology continue to be challenged by those advocating “intelligent design” or some other version of creationism (Kutschera 2003b Pennock
2003). This challenge to rational and scientific thought – one that remains insensitive to the huge body of evidence supporting evolutionary biology – is as persistent and pernicious today as it was during the time of Darwin.
We have no wish to explore the delicate and sometimes

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This is from today’s news. Husband and wife have been trying to have a child. No luck. Turns out the husband does not produce sperm. One solution would be to use sperm from some third-person. They didn’t want to use sperm from a stranger. And they wanted some genetic connection to the husband, but he has no brothers. What to do? How about using sperm from the husband’s father?

Now I realize that this seems weird on some level. It means that a child would be both the son of the husband (legally) and the 1/2 brother of the husband (genetically). It means the husband’s father would simultaneously be genetic father and social/legal grandfather. (I am not sure if “legal grandfather” really means anything, but perhaps you get the idea.) But is it the sort of thing we should object to? And if so, why?

First off, I’ll note that for those who value the genetic connection and those who worry about the donor conceived there are some strong positive points here. The child would be closely tied into the family of the gamete provider. There’s no issue about not having access to broader family or to medical history.

But the article does relate some concerns. Here’s one:

However, one concern in these situations is that the person who donates will want to act as a parent to the child. In the case of the couple from the Netherlands, the “grandfather” may find it hard to resist inserting himself into the family, said Arthur Caplan, bioethicist at the University of Pennsylvania.

“I’m not saying it can’t be done, I’m just saying it’s ethically high-risk,”Caplan said.

My first reaction to this is that the concern voiced (that the sperm donor may think of himself as a father and things could get complicated) is precisely why some people really want an anonymous donor. What better way to protect yourself from this risk?

This makes me think that if you really worry about the sperm donor being unable to have a narrow and restricted role in the child’s life (here as grandfather) you should either be generally opposed to use of third-party sperm or you should be in favor of anonymous providers. What I’m thinking is that the more tied into the child’s life the sperm provider is, the greater the risk of conflating roles and running into the “ethical risk” identified here.

But I think there might be a different approach, and it’s something I’ve alluded to before here, but perhaps not made so very clear. If we could more clearly separate the roles of sperm provider/father then we could more easily accept arrangements like the one described here. It’s the very fact that “sperm provider” is closely associated with “father” that raises the danger.

There are many other possible positions to stake out here. You could, for example, advocate for the use of third-party sperm but prefer situations where the provider will not be intimately involved in the child’s upbringing–as this grandfather quite likely will be. There’s something striking in that view–that the ideal sperm provider is not a total and unknowable stranger, but also not someone too close.

Maybe that’s enough to get a conversation started? I have to run now. I’ll try to check back in later today.

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73 responses to &ldquo Father/Son Sperm Donation? &rdquo

Some provinces in Canada now have legislation specifying that a sperm donor will not be a legal parent — unless everyone agrees to this at the time of conception.

I don’t see a problem with this. The same thing was mooted in “Frasier” btw:

“The best part of this episode, which is generally funny is Martin’s logical reasoning behind Frasier’s decision about donating his sperm, where he calculates that if Frasier, then Niles both refuse, Lilith will have to come ‘to the source’, meaning him. His irrational spurts of thought here are hilarious as he imagines having a child with Lilith, before saying: ‘And if you and Lilith got back together, you’d be his step-father and his brother and Niles would be your son and his own uncle. It’s almost worth doing just so that I can tell the story.’ “

this is sarcasm? or are you saying you really think this is ok?

in india , genetical ties are given inportance , here if husband dies , then lady can be remarried to his brothers , so i dont see any problem in this having grand faher’s sperm . so that child will be legally n genetically ours . we indians hv great respect for grand father or grand mother , so i dnt think that if grand father is provoding sperms , he will claim his parent hood on the child .

You know here’s the thing, this is just all kinds of messed up. What are they thinking? This kid is going to end up in therapy with all the crazy double code talk. The kid is going to constantly be having to translate back and forth my father is called my grandfather and my brother is called my father and my mother by virtue of having had a child with her husband’s father has in theory turned herself into my father’s kind of step mother and it gets more and more and more twisted as they go further and further away from reality.

There are titles that identify who you are in relationship to other people based on your specific point of orign. Anyone can take care of you not just anyone can pretend to be your point of origin. Siblings take on parental duties all the time but they are still siblings. Its just lying is what they are doing they are making up they are swapping the definitions of two commonly used words in the english language and then they are going to act like its not lying. Choosing the wrong words to describe something makes it difficult to understand what a person is talking about and when someone deliberately wants to make it difficult for other people to understand what they are talking about its called lying. If you don’t see your sibling as your sibling but more of a distant cousin, and you introduce them as a distant cousin rather than as your sibling your lying. If you want someone to think that your child’s brother is his father because you prefer their reaction and the way they treat you like a normal married couple with biological children that is perfectly understandable. Of course you prefer the reaction you get when you make it seem like something its not you create a fantasy land and give yourself permission to just bald faced lie to everyone you encouter because not everyone needs to know the details of the child’s conception. They are going to be teaching the kid to act as if his brother is his father and as though his father is his grandfather. Why are they doing this? Why are they going to such great lengths to put on a show? Why can’t the kid just be his father’s child and his brother’s brother even if it is messed up that his mom had a baby with her husband’s father. No its not incest and no its not physically unhealthy for the child. It is lying unless you redefine the meaning of the word lying to suit yourself. Oh not everyone needs to know. That line has personally f’d the heads up of so many of my friends. They can’t just live authentically as who they are the child of the people that made them. They have to serve as someone elses something they have a job to do and often at the expense of their own identity and place in the order of things. Its just real messed up all this bargaining that people are doing with other people’s realities. They have to be born into this weird lie where they pretend they are telling the truth by swapping definitions up means down and good means bad. Crazy

My cousin had a baby when she was 18 & wasn’t equipped to handle to it, nor was the baby’s father. My cousin’s parents (my aunt & uncle – his biological grandparents) adopted the baby. Everyone was very open about the biology of the situation.

Despite your claims to the contrary, nobody required therapy. In fact, the baby grew up to be a charming young man who’s now a plastic surgeon.

Just because you wouldn’t have the coping skills to deal with the situation, you shouldn’t assume that other people lack the emotional skills to deal with complex family situations.

of course! thousands of kids are raised by grandparents and suffer no harm. your situation has nothing to do with this situation.

It goes directly to Marilyn’s assertion that a child will be confused because of the family “title” issue.

Kisarita they shuffled titles so the father is called brother and the grandparents are called parents. Its one of those “i don’t think of them as…” situations where they know things are one way but prefer to pretend they are something else because they prefer the reaction they receive to the made up kinship titles.

not to mention the confusion of your mom being married to your brother (who no one will actually admit is your brother because they all know its too wierd)

Half-brother. It’s not illegal for a man to marry his son’s wife after the son stops being married to her for whatever reason. Apparently it is important that a man be able to marry his son’s wife. Even if it was a prohibited relationship to marry (and that means, even if sex and procreation was prohibited), it wouldn’t be incest, which is a special subgroup of prohibited relationships that are related by blood:

MGL Chapter 272 Section 17 Incestuous marriage or sexual activities. Persons within degrees of consanguinity within which marriages are prohibited or declared by law to be incestuous and void, who intermarry or have sexual intercourse with each other, or who engage in sexual activities with each other, including but not limited to, […too gross to repeat…], shall be punished by imprisonment in the state prison for not more than 20 years or in the house of correction for not more than 21/2 years.

See, so though a woman isn’t allowed to marry her daughter’s husband and a man isn’t allowed to marry his wife’s mother, they would not be committing incest, only fornication. They are still not allowed to have sex because they are not allowed to marry, but the crime is no worse than if they were unrelated and allowed to marry.

They adopted but did not change their titles from what they were biologically? That makes sense. Of course I could handle it if I was legally adopted by my grandparents and referred to them as my grandparents and to my father as my father rather than my brother. Grandparents have been raising their grandchildren for eons its perfectly normal and common. What would be strange is if the grandparents revised their titles for no reason. That is what I think is confusing, not the raising. Sorry if I was not clear

No. They referred to them as “mom” and “dad” and nobody required therapy, despite your claims to the contrary. Again, don’t assume that because you couldn’t emotionally handle a situation that other people lack the necessary coping skills.

ah how confusing. to know things are one way but pretend they are another. Well whatever works for them

Don’t assume that just because some people are able to seemingly handle a situation that it is OK to put more people in that situation. I survived a mass murder OK, but no one should ever be put in that situation.

i would consider this incestuous.
men should not be conceiving children with their daughters in law.

I’m not confused by the “jargon” and I really don’t see a problem with this. I do however have a huge problem with people using an anonymous donor.

If I found out that my genetic father was actually my grandfather, I wouldn’t be too bothered by it even in the unlikely event my mother had had sex with her father-in-law, but I’d be *very* disappointed if I found out that my genetic father was some unknown donor at a clinic, and it was unlikely I’d ever be able to find out who he was. I actually thought for several years that my father wasn’t genetically related to me btw, and I’m still not 100% sure.

It’s interesting, but in Massachusetts, a man is allowed to marry his son’s wife (after the son stops being married to her, presumably by death because the statute pre-dates rampant divorce). This relationship is the one relationship that is not mirrored for men and women: a woman is NOT allowed to marry her daughter’s husband.

Section 1. No man shall marry his mother, grandmother, daughter, granddaughter, sister, stepmother, grandfather’s wife, grandson’s wife, wife’s mother, wife’s grandmother, wife’s daughter, wife’s granddaughter, brother’s daughter, sister’s daughter, father’s sister or mother’s sister.

Section 2. No woman shall marry her father, grandfather, son, grandson, brother, stepfather, grandmother’s husband, daughter’s husband, granddaughter’s husband, husband’s grandfather, husband’s son, husband’s grandson, brother’s son, sister’s son, father’s brother or mother’s brother.

See, and it’s not just an oversight, the discrepancy also shows up the other way: a man is not allowed to marry his wife’s mother, but a woman is allowed to marry her husband’s father.

But in this case, the son is still alive and married to his wife, so it should be illegal for the father to impregnate his son’s wife, just as it should be illegal for anyone to impregnate her except her husband. I’m glad to have a consistent position that all intentional procreation is unethical and there is no right to procreate with someone you are not married to, and all sperm and egg donation should be shut down and everyone who facilitates it should be fined and jailed.

That is one curious statute. The man can marry his son’s wife but not his grandson’s wife? I’d love to know the reasoning for the exception for son’s wife.

That said, it doesnt’ follow that because he cannot marry he cannot donate sperm. You can make the argument from one to the other but there would be several intermediate steps. Among other things, I think you’d have to essentially equate donating sperm to her to marrying her. You may make the equation, of course, but not everyone will.

if we were told that the father in law and the daughter in law were going to have sex, most of us would be disgusted.
we can try to dress it up in medicalese but its not enough- most of us will continue to remain disgusted only we’ve let the jargon confuse us as to why.

This is a really interesting thread. One thing it makes me think about is why we react so strongly to incest–what the core problem is. If it is an inbreeding concern, then it ought not to be present here. But some people say it isn’t about inbreeding anyway, but about social relationships. (Would sex between adopted brother and sister bother you? No inbreeding, but very strong social relationship.)

Anyway, the father-in-law and the daughter-in-law are genetic strangers, so that’s not the issue.

It’s interesting, too, that Kisrita equates AI insemination with sex, in terms of the reaction at least. You’d think that to the extent incest is about disrupting social relationships then it’s about sexual conduct–whether procreative or not. So oral sex between relatives is just as bad, because it isn’t about genetics and reproduciton. But for me, AI is a world away from sex. One has nothing to do with the other.

I think I see the outlines of my next post…..

Julie, almost all humans of all time, (including the vast majority today even in the age of ART) come about through sex. It is artificial to separate sex and reproduction.
Can sexuality be expressed in non reproductive ways? of course, when one is making a rational, thought out decision. But if we’ve gotten to the stage of a rational thought out decision, that means that taboo, the visceral, gut level disgust, has already been eliminated.

Did I already answer this? If so, I apologize. I’ve lost track.

Yes, it is artificial to separate sex from reproduction but that is exactly what ART does. And that’s why it has really forced so many questions upon us. At the same time, changes in law and culture have separated sex from marriage, by which I mean that sex outside of marriage is commonly recognized and accepted. Without these changes I wouldn’t have nearly so much to blog about.

I understand that for some people (and perhaps you are among them) because sex is commonly linked to reproduction (and reproduction commonly linked to sex) the two are always associated. But it’s just as true that for many people assisted reproduction has nothing to do with sex. To take an example I don’t think we’ve thrown out–most lesbians who use AI do not think they’ve had sex with a man and would see a huge difference between insemination via intercourse and insemination via AI. (The law draws that line, too, in many places.)

So Julie would many lesbians reject the scientific definition of sexual reproduction? That definition actually does not include intercourse or skin to skin contact or love or pleasure or all that. Its just the cell thing.

No, most of the lesbians I know understand sexual reproduction. But when you ask a friend “did you have sex?” you aren’t just asking if they engaged in sexual reproduction. When you say to an adolescent “sex is an important thing and you need to wait till you’re ready” (or whatever it is you do say) I think you mean something more than just wait to reproduce. I think you mean wait to engage in wide (and admittedly ill-defined) range of sexual activities.

Apparently in some circles teens do not count oral sex as sex–and of course if sex means sexual reproduction then they are right. Thus, you can engage in oral sex and honestly say you’ve never had sex. I suppose there is some technical truth there, but I think this refining of language is somewhat dangerous. I suppose I may sound puritanical but it isn’t okay with me that thirteen-year-olds engage in oral sex on the theory that it isn’t sex.

At the very least, I think there needs to be some category name for the behavior that is sexual (whether it is reproductive or not) because sometimes we need to talk about that category of thing. Maybe we also need a word for reproductive conduct, whether it involves sex or is in a laboratory)–and maybe that is ‘sexual reproduction’ or even just ‘reproduction.’

There are lots of reasons we prohibit incest, and inbreeding is one of the biggest but not the only reason. We don’t have to explain to you exactly why it is repugnant, nor do we all have to agree on why we think it should be prohibited.

And you are wrong, AI is simply a sex position, like missionary or doggy style. It’s not listed in the Kama Sutra because there is no love-making going on, which is the same reason forcible rape isn’t in there. But just because it isn’t love-making doesn’t mean it’s not sex.

It is of course true that no one has to explain anything to me–I just write a blog and people can choose to comment or not. If they choose to comment, they choose what to say. But it does seem to me that it is useful to think about why we find things repugnant. It is possible that the reaction isn’t warranted and that rational examination can reveal that. To take a silly example, many people find worms repugnant, but I don’t think there is a real reason to do so. Understanding the reaction may allow some people to change how they feel about worms–and given that worms are quite useful, I’d say that is a good thing.

It’s also fine for you to express your opinion that AI is simply a sex position, but it might be nice to note that it is an opinion. We disagree. That’s fine. But this isn’t a disagreement about a fact that you or I can hope to verify. If I said I bought my house for $10 you could prove that I’m wrong–because that’s a historical fact. In the same way I take it you are right (and that I could verify it, though I haven’t) in what you say in another comment about what Massachusetts law provides. So here is one that we disagree on.

I suppose I could invoke the oft-cited Humpty Dumpty quote here–that a word means what I want to mean. You want to define sex to include AI and that’s your perogative. But I wonder if giving the term (as used in the phrase “having sex,” right?) so broadly robs it of some of its meaning. I guess I do not understand what the essence of having sex is in your usage. I’m not sure how I’d know what it meant if you told me two people had sex. And so I’m not sure we’d be communicating usefully given how far apart our definitions seem to me.

All that said, perhaps we can just agree to disagree here. I do not think that I can persuade you to change your definition–since in your view I’m just flat out wrong. I also don’t think you are going to persuade me, as I don’t see the utility of switching to your definition, nor do I see that it is one in common use. (The last point means that I don’t see that using your definition would make what I say more comprehensible to readers–it goes back to communication.) So I propose we agree to disagree and leave this part of the topic here. I do try to be careful to say “in my view” frequently in part as an acknolwedgment that others (like yourself) have different views. I’ll continue to do so.

I mean we (those who think something should not be allowed) do not have to explain why we feel that way to anyone, or all agree about why it should not be allowed, in order for a law to be enacted and for it to stand up as rational and Constitutional. Courts need only imagine that there might have been rational reasons for enacting a law, they don’t have to know what they were.

And I won’t agree that just because you think AI is not sex, that it means that it is only an opinion that it is sex. It is a sexual position. Anything that might bring male and female sex cells into proximity where they might join together to make an embryo is a sexual position. Same-sex couples do not have sex, any more than a cat and a dog do. They can enjoy intimate pleasures involving their sexual organs, but it isn’t sex, it isn’t sexual intercourse, and that isn’t an opinion.

how ridiculous john. of course dogs and cats have sex. Sex means all these things! Sex means sexual reproduction as well as the stimuluss and feelings that go along with it, even if their expression is not reproductive!

I mean with each other, sorry. I was gonna a man and a dog, but I changed it to be less offensive into the generic incompatible partners of cat and dog, who if they were to have intercourse it would not be sexual intercourse, though I guess thats what we’d call it for lack of a better term. What I mean is, sex is whatever brings the sex cells together to reasonably possibly make new generations.

Despite finding it fascinating to challenge my preconceived (no pun intended) notions that sex is something other than the fun part – its scientific meaning, I gotta agree with Julie here. If a person wants their opinion to be taken seriously and turned into law, it had better be logical and substantiated and clear. I’ll add to that it ought to be fair in its distribution of rights and obligations as well. But if law makers don’t know why they are passing a law that is bad. Actually its pretty bad to do anything when you don’t know the reason or won’t be knowing the outcome. Its just blind to make a move like that.

Well, sure, I’m saying why we should prohibit gamete donation, all the time, that’s fine. We should certainly talk about how it hurts kids, undermines the family and morality and important social standards and conventions, causes lots of problems, etc. The point is, Julie is pitting one person’s argument against another, singling out each argument one at a time to show that it doesn’t always apply, or that not everyone has that objection, so it’s invalid. She’s demanding opponents agree on every reason and articulate and prove them all empirically, because she knows that is an impossible task, and I’m saying we don’t have to do that, legislatures can act on the totality of interests and concerns and apply inarticulated gut feelings for prudence, including vague and unproven theories and feelings.

I do not mean to demand that all those opposed to AI or ART have to agree on the reasons they are opposed. The nature of coalition building (which is how legislation gets passed lots of times) is that people agree on an outcome for different reasons. That’s fine. But I do think it is useful to examine the different reasons people have for reaching the same conclusions.

For instance, many people might agree to ban AI with anonymous providers. For some, the problem is “anonymous” while for others it is AI more generally. I think this is an important distinction to observe. It doesn’t mean people couldn’t all vote together for the same law–of cousre they could. But suppose there were instead a law that barred use of anonymous providers. Some might support it and others not. And some who like AI might also agree on the ban on anonymous providers. So in the end a law that banned anonymous providers (but not all AI) might please a larger group of people. I do not assert this to be the case–I just want to illustrate why I think it is important to discuss the reasons behind the positions people take.

I’ve been thinking about the definition you are using for sex and it has lead me to a question. If I mistate your view, I do so inadvertantly–I really have been trying to understand it.

Do you have a term for conduct between two adults that is erotic, intimate and sensual but is not aimed at procreation? I ask because I think I tend to include this sort of conduct when I use the term “having sex.” I think I understand that you would not include it. Your definition of sex is conduct that is reproductive–which is why it includes AI as well as hetersexual intercourse, right?

But then I wonder if you have some particular term for joint erotic conduct that is not reproductive or if this kind of condcut is just on the same level as any other conduct two people might engage in.

I’m not sure I’m asking this very clearly but I would draw a line between erotic conduct and non-erotic conduct even if the erotic conduct wasn’t reproductive. Would you draw a similar line? And if so, what do you call the erotic but non-reproductive conduct, as you do not call it “sex.”

i do not draw any line- its all sex
while its pretty clear that the reason for the existence of sexuality is for procreation, it’s actually a pretty amorphous thing that can be expressed in many ways and use for other purposes ie recreation and intimacy

Sorry–didn’t mean you–meant John.

I don’t know if it is so clear what the purpose of sexuality is, although of course reproduction is important. But people do not go into heat as animals do. We are set up to engage in and enjoy sexual conduct even when we aren’t fertile. Some evolutionary psychologists say that sexual activity (not necessarily intercourse) stimulate various chemical reactions in the brain which are essentially addictive. I think some speculate that it may encourage pair bonding which helps ensure the success of our incredibly dependent infants.

“If we could more clearly separate the roles of sperm provider/father then we could more easily accept arrangements like the one described here. It’s the very fact that “sperm provider” is closely associated with “father” that raises the danger.”

I would say the opposite- the obfuscating of the the sperm provider=father is the real danger here. Julie, you have graduated from promoting fatherlessness to promoting incest. I hope you are proud of yourself.

I would not promote incest, but I don’t see the incest here. Remember that to me a sperm provider isn’t a father. (Obviously a sperm provider is a genetic father, but I distinguish that use of the term.) A sperm provider is a person who provides sperm and can have a role in the child’s life that it is up to us to define. If that is the case, then there is no incest issue.

I know a number of families where there is a known sperm provider who has some role but the person isn’t understood to be the father. Is it possible that the reason you react so strongly to this is because may not acknowledge the possibility of separating these two roles.

You would not condone incest but your willing to risk it for people other than yourself who have no control over the situation. Nice.

I do not know what you are talking about, but see several possibilities. Do I risk incest for other people because I think the arrangment here could work or are you referring to past discussions about use of unidentified donors? Or somehting else? I really cannot reply unless I know what you are meaning to refer to. (And could you please watch your tone? Sarcarsm (as in “nice”) can rapidly lead to the degredation of discourse and I work hard to try to promote discourse here.)

You said that you would not condone it.

Yet in the past you have stated that you believe there is nothing wrong with gamete donation and have wondered if its really a problem that sometimes donors have upwards of 100 offspring.

I was out of line in my tone. And off topic for this post. I’m reacting to the fact that it is inconsistent to say that you don’t condone incest when you promote gamete donation? Is incest for you based on genetic parenthood or social parenthood? Is it not incest if a sperm donor had sex with his offspring because he is not legally the father? I’m trying to understand how its ok to choose to risk another person’s ability to avoid incestuous contact and still say that your not promoting incest. At the very least gamete donation is akin to reckless endangerment placing someone at increased risk for something and they have no control. I should have said that its not nice to do that. Its not polite its kind of rude to advocate for people compromising other people’s ability to differentiate between relatives and non relatives. The fact that you seem to hold opinions that are at odds on this topic makes it look like you think of all that as collateral damage worth the risk because it does not directly hurt the people using the gametes.

I don’t think it is inconsistent to say that I don’t promote incest even as I approve of gamete donation, because I don’t equate the two.

First off, I am very concerned about what I called the psychological/social aspects of incest–by which I mean sex within a familiy setting among family members. But I do not think that engaging in AI is the same as engaging in sex (though I know others do.) I think if you’ve got a family where the members view donating sperm to the daughter-in-law as something not at all like having sex with the daughter-in-law. Which means that as long as there is some counselling to establish what family members really feel about this I think you can avoid the dangers of incest and go ahead with the sperm donation. And to the extent the incest problem is about genetics and inbreeding, I don’t see any danger of that at all in this setting. The universe of people off-limits to this child would be essentially identical to those off-limits were the child genetically related to the husband–this isn’t the one hundred offspring problem.

Now as for the 100 offspring problem–I haven’t meant to be cavalier about that and it may be that I need to go reread all that I’ve written. I do think having hundreds of offspring can be problematic. I’m not sure how big a problem the unintentional incest thing is, in truth. I believe that the one time it was specifically discussed as having occured (in the UK during a legislative debate) it turned out to have been fiction. I can also see other ways of dealing with this incest issue–I wonder if we aren’t heading towards a lot more genetic testing in our lives. And if you had more transparency about sperm providers (and I have written about that), this might take care of it as well. I don’t think any of these things are easy to accomplish, but this doesn’t mean that I don’t think tehre’s any issue here.

Finally let me try to answer some of the more specific questions you pose.

I think it is important to consider both aspects of incest for a variety of reasons, but I also think I need to be careful to think about them separately because they are different.

Yes–I think it is incest for a person to have sex with their biological father, even if he isn’t a legal or social father. And I would define “have sex” rather broadly. This is partly because I think a person who did this inadvertantly would be horrified and repulsed and that does worry me. It’s actually curious to me that this doesn’t come up as a problem with using anonymous donors more than the hundred offspring concern. It’s worth thinking about how to guard against this–though in the situation that is the subject of the main post I wouldn’t worry about it.

You didn’t ask but I also think it is incest for a person to have sex with their adoptive father or any other genetically unrelated but psychological/social/legal father, even though there is no genetic component. This is the other aspect of incest.

Perhaps there are some incest concerns with all use of third-party gametes, but except in the hundreds of offspring cases, I think the risks are small enough as to not warrant stopping use of third-party gametes. There might well be other things we can do to reduce risks even further and that wouldn’t be bad. Again–relying more heavily on identified or identifiable gamete providers will surely help.

OK first I don’t look at IVF or IUI as having sex, I was just throwing it out there to challenge what does and does not constitute sex because its not pleasure or even consent and its not intercourse either so what’s left by process of elimination is contact with sexual organs. In reading the strict medical definition of sexual reproduction it mentions nothing about the people behind the cells or what they may have done in order to get the cells into proximity where reproduction can occur. I want to make it clear that I have the same general mindset as the average person about what it means to say that someone had sex.

Fair enough. I think it was John that did not share this view. “Sexual reproduction” is possibly used to distinguish between that and “asexual reproduction?” That’s important biologically, of course. Some people talk about “procreative sex” to distinguish it from the broader category “sex.” And then you could just say “reproduce.”

Bottom line is that we probably do not use language consistently nor do we all use it in exactly the same way, which at once makes things difficult but interesting.

Now I can see where a donor can say the risk of me unintentionally dating one of my unknown children is low, but its me taking the risk and I’m willing to gamble with my own ability to differentiate relatives from non relatives because the benefits outweigh the risks for me. But the donor is also risking his relative’s ability to avoid dating one another. The risk may be small but it is certainly not his to take. It would be their risk to take and they have no say in the process and that is precisely why it needs to stop.

You think its ok because your not risking your own ability to prevent yourself from getting into a romantic situation with a relative. Why should you or anyone else think they have the authority to decide for themselves whether or not the benefits of gamete donation outweigh the risks they’ll be taking.

You know, I know donor conceived young people, most of whom live in families where it is obvious that they are donor conceived. They know what they do and do not know and so aren’t oblivious to the risks you mention. Obviously the more you know about the sperm or egg provider, the better able you are to protect yourself from any possible risk and I see this as a good reason for enhanced transparency–which includes information about the providers being made available to the children. I’m not persuaded that it is a reason to cease using third party sperm entirely, though.

The incest taboo serves essential functions in society:
1. At the most basic level, to encourage genetic diversity and avoid excessive inbreeding
2. To clearly define familial roles and relationships
3. As a consequence of #2- to help prevent sexual abuse of children

I think this is probably true, although I don’t know that all will agree. There are other ways to state 2 and 3. I’ve read some about creating a sex-free environment in which children are raises, so that children can have close physical initmacy with adults (parents, aunts, uncles) without it being sexualized. I think that is basically what you said. And I’ve also read about the idea that in a tribal culture, people need to marry out of the tribe in order to forge ties tribe to tribe.

In any event, with those purposes in mind, I don’t see the incest issue here. there’s no concern about 1, right? And as for 2/3, there’s no sex. No one is proposing insemination via sex.

I like to get back to the original meaning of words to see just how badly we’ve butchered them. The fact is the true definition of the words we use is always there in the backs of our minds even if we grow accustomed to using that word to describe something entirely different yet somewhat related. Never is this more evident than with sexual reproduction. In fact, the father in law did have sex with the daughter-in-law, they just did not have intercourse or intimate contact with one another in order to sexually reproduce together. Its just a boring scientific fact creeping forward in our minds leaving us perplexed as to why this arrangement does not sit well with us. Changing the meaning of words is of course all part of making it easier to lie to ourselves and to one another. Its not wrong for the father in law to have sex with his daughter in law really but the fact that everyone pretends it did not happen is the peculiar thing. The fact that they’ve made a child whose job it is to pretend that he is his brother’s son is not fair to that child. Its not fair that he can’t simply be good enough being who he really is having the parents who he really has. His job is to make the father’s sterility go away and make his mother have a biological child. Its really a bit much for one person to bear without cracking. I bet the kid will pull it off like its no big deal. He’d better. They’ve gone to so much trouble to have him.

Here is the definition of sexual reproduction. Its a nice refresher:
“Sexual reproduction
From Wikipedia, the free encyclopedia
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction they are: meiosis, involving the halving of the number of chromosomes and fertilization, involving the fusion of two gametes and the restoration of the original number of chromosomes. During meiosis, the chromosomes of each pair usually cross over to achieve homologous recombination.
The evolution of sexual reproduction is a major puzzle. The first fossilized evidence of sexually reproducing organisms is from eukaryotes of the Stenian period, about 1 to 1.2 billion years ago.[1] Sexual reproduction is the primary method of reproduction for the vast majority of macroscopic organisms, including almost all animals and plants. Bacterial conjugation, the transfer of DNA between two bacteria, is often mistakenly confused with sexual reproduction, because the mechanics are similar.
Evolutionary thought proposes several explanations for why sexual reproduction developed out of former asexual reproduction. It may be due to selection pressure on the clade itself—the ability for a population to radiate more rapidly in response to a changing environment through sexual recombination than parthenogenesis allows. Also, sexual reproduction allows for the “ratcheting” of evolutionary speed as one clade competes with another for a limited resource.”

I don’t think I’d say they had sex with each other at all. Let’s suppose a woman who has never had sex decides she wants a baby. She goes to a fertility clinic and they make an embryo in the lab and then put it in her to grow. I would say that after the fact, she has still not ever had sex. The embryo was conceived in a lab not through a sexual act or even artificial insemination where it would still be concevied in the woman’s body.

Are there are any species that have “sexual reproduction” without any kind of sex act? Otherwise I’d simply say it’s a term that made sense before artificial reproduction technology existed, since the only way to reproduce was through having sex.

Right Rebecca but your thinking about sexy sex. The kind that’s fun. To be sure she would no longer be a virgin right? They’d have to break her hymen to implant the fetus. The entire process of implantation or retreival involves transversing a woman’s sexual organs and the only reason we don’t consider that to be sexual contact is because the person doing the contact is a doctor. That and that the intent of the contact is not for someone’s sexual gratification. Even though it is for someone’s reproductive gratification.

You would agree that the woman and her father-in-law are just a man and a woman right? And you’d agree that they reproduced together to create a child, right? Then they have met the scientific criteria for having gone through an act of sexual reproduction despite the fact that they had no intimate skin to skin contact.

“Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms.”

Well, some women break the hymen without ever having had sex if they have a bad injury/fall in that area so I wouldn’t say hymen = virginity as an absolute rule, anyway.

How did sexual reproduction triumph over asexual, since it requires two variations of an organism rather the just anyone? How did it even get started at all?

You just asked one of the biggest questions in evolutionary biology - one which still hasn't been definitively answered. There are several possible explanations of various plausibility, and the true answer could be any one of them, a combination of them, or even none of them.

But to understand them, and assess how likely they are to be accurate, you first have to understand exactly why it would seem that sexual reproduction seems to be less efficient. If we assume every individual contributes two offspring to the next generation, then an asexually reproducing population will grow at an exponential rate, while the sexually reproducing population will merely maintain its current numbers, since each offspring requires input from two parents. Even worse, asexual organisms can reproduce whenever they can muster the resources, but sexually reproducing organisms must put additional time and energy into finding a mate. This is called the twofold cost of sex. Any explanation of how sexual reproduction evolved must provide a convincing explanation as to how sexual reproduction manages to overcome this considerable disadvantage.

It can be argued (indeed, it has been quite a bit in this thread) that a sexually reproducing population would be competitive due to its increased genetic variation making it better able to adapt to novel or existing conditions. This might be workable as an explanation for why sex continues to exit, but it doesn't cut it as an explanation for why sex first appeared. The benefit of a population with lots of variability appears only once that population is already established. This might be a considerable number of generations in the future, and the process of natural selection certainly doesn't operate with the foresight to aim for such a goal. In other words, selection that favours variability doesn't nullify the twofold cost quickly enough to ever allow sexual reproduction to take off. Luckily, there are better explanations.

The life cycle of sexually reproducing organisms invariably switches between stages with a single copy of each chromosome in every cell (haploid), and stages with two copies in every cell (diploid). There are several advantages to this:

In the diploid stage, cells are capable of repairing quite extensive DNA damage by aligning the two copies of a chromosome and using one as a template. This is a substantially better repair mechanism than any asexual species can manage, which might tip the selective balance in the favour of sexually reproducing organisms in an environment where agents causing DNA damage are common.

A consequence of this repair mechanism is genetic recombination between chromosome pairs, both during repair and during meiosis, the cell division event which marks the transition from the diploid state to the haploid. This is part of the reason for the larger degree of variation possessed by sexually reproducing species that I mentioned earlier, but it also has more immediate consequences. Recombination might give an advantage to sexually reproducing organisms in two ways.

Firstly, it reduces the effect called "genetic hitchhiking". In asexual organisms, a gene that is particularly favoured by selection may cause other genes - even those with deleterious effects, such as malfunctional mutants or genetic parasites - to be favoured along with it, simply because the deleterious gene is very near to the favoured gene on the chromosome. The end result of this is that the increase to the organism's fitness caused by the favoured gene is somewhat counteracted by the hitchhiking gene. Recombination allows pairs of genes to be switched around, meaning that it becomes much more difficult for other genes to hitchhike along with them. In other words, recombination allows an organism to reap the full benefits of a beneficial gene without having to suffer the negative effects of other genes which otherwise couldn't be decoupled from the beneficial gene. For much the same reason, recombination allows deleterious genes to decline and disappear from the gene pool considerably more quickly than they would in asexual species.

Secondly, recombination might allow combinations of beneficial genes to come together more quickly than would happen in asexual species. This would produce a more fit genotype overall in a shorter period of time, and could produce a superior genotype in a single generation if there is any variation at all present, countering the twofold cost of sex.

While I talk a lot about overcoming the twofold cost of sex, it would seem that there are still plenty of situations where even all these advantages aren't enough for sexually reproducing organisms to out-compete asexually reproducing organisms. After about 2 billion years of constant, supercharged sexual evolution, the overwhelming majority of living things - however you cut it - are still asexual.

None of what I said mentions differentiation of the sexes in any way. It's likely that sexual reproduction simply didn't have any distinction between gametes when it first evolved (a state called isogamy). Since its original purpose was likely to enable more favourable DNA repair and recombination as I just described, that's not surprising. Differentiation into two (or more) mating types is something that would have come later. The reasons why this happened are every bit as fascinating as the reasons why sex evolved in the first place however they also deserve another post all to themselves, so I'm not going to get into them here.

Rather late to this thread as I am, I expect people have already described most or all of this. But I love talking about it!

Monday, March 13, 2006

The Conditions of Kindness

A recent paper by Michael Gurven in Current Anthropology (1) explores how choices about whether help is given to others depends on how generosity is returned.

Asking a favour from a mafia don is not without its costs. It might get you out of a tight spot, or enable you to avenge an enemy, but it comes with burdensome strings attached. The time will eventually come when you are called on to return the favour, and you had better not think about reneging on your obligation.

Even among friends, the returning of favours, or reciprocity, looms large. Most people most of the time, of course, do favours for friends and are not motivated by the prospect of a profitable return on the altruistic investment – it simply feels good to help people we like. But when the flow of favours is unidirectional, we normally notice, and it doesn’t feel good. We feel taken advantage of, which prompts feelings of resentment and, taken to the extreme, can cause the breakdown of friendships.

In the early 1970s, Robert Trivers developed the idea of reciprocal altruism (2) to explain some of the puzzles of animal and human cooperation. The basic idea is simple: you scratch my back, and I’ll scratch yours. Lets say I have a surplus of food today, and you’re going hungry. It hurts me less to give you something to eat than it benefits you (that is, although it might cost me 5 ‘health points’ to lose this food, you might get 10 points by receiving it, particularly if I’m relatively stated and you’re desperately hungry). Fast-forward to a time when the tables are turned, and I’m hungry and your larder is full: if you help me out, we’re square, and we’re both better off than we would have been if we had never helped each other (because we gained more benefit by being helped when we needed it than we lost out when we helped). In this way, a self-serving Darwinian creature can profit from entering into cooperative actions, provided it can discriminate cooperators from non-reciprocators.

The most famous (though not necessarily the best) strategy for getting reciprocal altruism off the ground is Tit-For-Tat (TFT). In this strategy, you cooperate on the first encounter with someone, and then do whatever he or she did on the previous round. So if they did not cooperate on the first move, you withold help on the next round. Likewise, if your partner cooperates, you cooperate on the subsequent move. Although TFT does well in reaping the benefits of cooperation, and of withholding help in some circumstances, it can be beaten by a range of other strategies. TFT, and reciprocal altruism in general, have limitations in explaining the long-term nature of human social interactions, and other routes to the evolution of cooperation are no doubt key to explaining human altruism.

In reciprocal altruism, the benefits of cooperation flow directly back to helpers from those they have helped before. But this needn’t be the case. Benefits can flow back to altruists can just as plausibly through indirect routes: A helps B, B helps C, and C helps A (3). If a reputation for being a good collaborator means that you get more opportunities to participate in profitable cooperative ventures, even if this is with individuals that only know of your character indirectly (through hearing of your reputation), then cooperation can pay, even in a selfish world. Such systems of indirect reciprocity are pervasive in human societies, and have even been proposed to constitute the core of moral systems (4).

A crucial feature of systems of reciprocity, and perhaps particularly reciprocal altruism, is that whether or not you give help is determined by what sorts of benefits you are going to get in return. Giving is contingent on subsequently receiving. According to reciprocal altruism, the reason that cooperation can emerge in a world of selfish egoists is that cooperation is not a zero-sum game: my gain is not necessarily your loss – we can both win. In a world of cooperators/reciprocators that shun cheats, it pays to be a cooperator.

The contingency at the heart of reciprocity can take a number of forms. For instance, giving someone some food might be contingent on getting the same quantity of food in return. Or it could depend of receiving the same proportion of the stock we gave away, regardless of the absolute amount returned. Giving might also be contingent on overall levels of exchange between whole families, rather than on an individual-by-individual basis. Alternatively, giving and sharing can depend on the amount of effort that people put into solving problems such as gathering food – it is one thing to do badly despite your greatest efforts, but another to do badly through sheer idleness. So we have here four types of contingency, what Gurven calls, in order, ‘quantity’, ‘standardised quantity’ (percentage), ‘frequency’ (of exchange between families), and ‘value’ (of effort put in or some other factor). Experiments at the interface of economics and psychology have, over recent years, provided support for the role of value in shaping what people think other people deserve out of group efforts, and Gurven’s study adds to this.

A number of theories have been put forward to explain the nature of human altruism, which stands out as an anomaly in the natural world because of the levels of help and cooperation between unrelated people in human societies. It is likely that the different theories explain different aspects of human altruism. However, they do differ in the types of contingency you’d expect to see in certain cooperative and altruistic actions, and so studying them can help determine which processes are operating in which situations.

Unfortunately, little attention has been paid to the different forms of contingency and their roles in regulating altruistic behaviour. So Michael Gurven, an anthropologist at the University of California at Santa Barbara, set out to explore these issues using data previously collected by Gurven and other anthropologists in two populations: among the Ache of Paraguay, and the Hiwi of Venezuela. Through a number of statistical analyses, Gurven demonstrates that contingency does play an important role in food sharing among these populations, and also that different forms of contingency operate in different contexts.

The Ache and Hiwi live in different ecological niches, and collect and consume a range of food types (for instance, the Hiwi lived near a river and therefore had access to fish). Gurven grouped food types together, and analysed the role of contingency in governing whether and how they were shared. The Ache diet was categorised into forest foods (such as meat and honey), ‘cultigens’ (such as sweet manioc, corn and sweet potatoes) and store-bought foods (such as bread and oil) Gurven also looked at contingency in ‘all food types combined’. Contingency among the Hiwi was examined by grouping food as meat, fish, ‘other foods’, which included fruit and roots, and ‘all foods combined’.

Gurven found strong evidence for contingency in sharing meat and fish among the Hiwi, although this wasn’t seen for resources grouped as ‘other foods’ (fruit and roots). On average, for every kilogram of meat given to another family 0.69 kg was given back for other foods, the return rate drops to 0.08 kg for every kilogram given. Among the Hiwi, the form of contingency called ‘quantity’ was the most prominent in the exchange of meat and when all resources were considered together ‘value’ had an effect similar in magnitude, though not quite as great. The transfer of fish among the Hiwi seemed to be predominantly contingent on standardised quantity (percentage).

Among the Ache, frequency and value contingency were most important for forest foods and cultigen transfer, and value stood out as an important determinant of giving when all foods combined were considered together.

The lack of contingency in the giving of non-meat (‘other’) foods is interesting – what is it about these resources that makes people share them differently? Roots and fruits, while making up more than 40% of the Hiwi diet, are the least transferred resources. A number of factors explain why giving of these foods is less contingent than for other resources, and why they are not shared much in the first place. First, the existence and location of fruit and roots, unlike animal game, is highly predictable. This means that there is low variability in the amounts of these resources that foragers return with (that is, collecting these resources is less subject to the vagaries of chance). Second, individuals typically gather fruits and roots at the same time, and are therefore usually stocked up or not at the same time. These two factors reduce the need to exchange these foods in the first place: you’re more likely to be without meat or fish than without fruit or roots.

These anthropological results tie in with studies in behavioural economics that reveal that people are motivated by notions of fairness based on labour input into collective actions. The notions of fairness built into human psychology give rise to, and are probably reinforced by, cultural norms that explicitly spell out what is fair and what is not. Gurven suggests that thinking about the types of contingent cooperation seen in his anthropological survey could “begin to bridge the gap between the short-term calculus of reciprocal altruism and the longer-term social relationships emphasized in cultural norms.”

It is important to recognise that although reciprocal altruism and TFT are highly contingent, the finding of contingency in the food sharing of the Hiwi and Ache does not mean they are engaged in a TFT strategy. It seems that the forms of contingency observed, and the motivations driving cooperative behaviour, are the product of psychological systems, buttressed and canonised by cultural norms (and also perhaps in part shaped by them), that promote long-term collaborations in a way that TFT cannot.

The value people attach to the effort other people put into collective actions, and their altruistic intentions, has, according to Gurven, been neglected in past explorations of human cooperation in the anthropological literature. Given the recurring importance of value-based contingency found by Gurven, more attention to value should be paid in future studies. In general, the behavioural outcomes identified by anthropologists and other students of the human social sciences need to be linked up with work on the psychological underpinnings of human cooperation. A problem as complex as human altruism is surely going to require a pluralistic, inter-disciplinary approach to clearly illuminate the multifarious facets of this perennial question.

I'll do drugs and rock and roll later. So, as it turns out, no doubt much to your surprise, the whole subject of sex is very interesting. I would say, after a bit of rooting around in the wilds of biology, that the origin of sex is actually as big a puzzle as the origin of life, if not an even greater one. Creationists, in fact, are all over it - in their view, sex could not possibly have evolved, so there you go.

Biologists no only wonder about where sex came from, they wonder almost as much about why it has stuck around. However, I must say that even though I'm not a specialist in the subject, I don't find that puzzling at all. Maybe having a bit of distance makes it seem clearer. Understanding why sexual reproduction is so strongly maintained, and is so nearly ubiquitous among the eukaryotes and particularly the metazoa, is actually very helpful in thinking about how it got started, so let me begin with the easier question.

It seems, at first, that sexual reproduction is a big disadvantage. First of all, you have to find a mate, which requires luck and effort. Second, your own genes get diluted, so if evolution is about gene selection, that would seem a big strike against sexual reproduction. You have to invest in making gametes which has some energy cost, and the process of fusing gametes to make a zygote can fail - it often does, in fact - reducing your rate of reproduction. Sexual selection pressure can drive evolution in odd directions, such as making big showy tails that attract predators and slow you down, or investing a lot in unproductive behaviors. (Tell me about it.) And the close physical contact required for mating creates one more way for pathogens to get around. So why bother with the whole thing?

Imagine two lineages of similar creatures, one reproducing sexually, the other reproducing asexually. Both have to live with pathogens and parasites, most of which are asexually reproducing prokaryotes that have very fast generational turnover. The asexually reproducing lineage has almost no genetic diversity. Occasionally a random mutation will arise, which will probably kill the organism, though once in a while a mutation will be tolerable or even favorable and the mutated lineage will persist. Nevertheless, a mutation in one lineage can never get combined with a mutation in another 100% of the animals are reproductively isolated. They don't mate and they don't mix their genes. If a pathogen evolves that can evade their immune systems, they're wiped out, extinct, so long, sayonara, good bye.

The sexually reproducing species, however, is genetically diverse. Harmless or favorable mutations that arise over time will eventually spread, in all possible mixtures, through the progeny. Some that might even be harmful if expressed survive because they are autosomal recessive. When the new pathogen comes along, it is likely that some of the individuals in the population will just happen to be resistant to it. They and their offspring will survive and go on to rebuild the population.

It gets even better than that because all that mixing and matching of genes creates all sorts of combinations that might just happen to be better than any one mutation by itself. A mutation that is harmful in the asexual lineage might just turn out to be favorable if paired with some other mutation, but the opportunity will only come along if there is sexual reproduction. In a nutshell, the sexually reproducing species can evolve faster, and create much more innovation. Hence it is no surprise that all complex, multicellular organisms reproduce sexually. If they didn't, they never would have developed such complexity, and that's why asexually reproducing organisms are all microscopic, one-celled creatures. Some multicellular organisms, notably plants, can also reproduce asexually, which is handy for producing lots of new individuals fast and covering a hillside with daffodils or whatever but also having sexual reproduction gives them all the advantages noted above as well.

Now, as for how the whole thing got started, that's a tough one. Lots of speculation actually centers around infections and parasitism -- two organisms getting their genes all mixed up together and then having to sort them out and mix them up again every generation. Maybe that Y chromosome is all that's left of a parasite.

Anyway, I'm not going there because I don't know where I tread. But I do know that evolution is inventive, but also conservative. It can only work with what it's got, which is why we don't have three arms even though it might be useful, or an eye in back to see what's gaining on us. So we're a social species, with very complex social structures and behaviors, and there just happen to be two different kinds of us, since we reproduce sexually. Now, evolution does drive a certain amount of sexual dimorphism simply because of the reproductive function. Men and women have different parts because they have to. The equation of investment in offspring also differs between men and women, and there's nursing as well. But it would be surprising if other kinds of sexual differences, in capacities or behavior, that one way or another enhanced the success of the species didn't also emerge.

It was fashionable back in the 1970s and '80s to believe that the differences in gender roles were all socially determined, and that human societies were possible in which the only differences between men and women were the direct consequences of gestating and suckling. Now I think it's becoming clear that much about gender roles is indeed socially determined and is highly mutable, but some things are not. There are differences between male and female brains and behavioral proclivities -- statistical averages, not absolutes -- and proclivities for different patterns of mating behavior, attachment to children, etc. For a while, it wasn't really possible to study these matters, and trying to sort out what is culture and what is wiring was not even permitted. But now people are working on it, and I do believe this will help us to know ourselves better.

From here, it gets to be pretty tricky. Sensitivities, and dudgeon, are high.

And don't get me wrong: It's important to study these issues in part because we might just like the answers after all:

"The so-called gender gap in math skills seems to be at least partially correlated to environmental factors," says economist and study researcher Paola Sapienza, PhD of Northwestern University's Kellogg School of Management. "The gap doesn't exist in countries in which men and women have access to similar resources and opportunities."

2. The ethics of human cloning

2.1 Therapeutic cloning

2.1.2 We believe there is reason to doubt the plausibility of some of these scenarios, and to think that other areas of research are more likely to advance these goals. But since this is not our field of expertise we will leave detailed criticism of the scientific proposals to others. We do not believe that these questions have any fundamental relevance to the moral acceptability of cloning since if the research involves fundamentally unethical practices, then the possibility of benefits arising can not make it acceptable. These issues are addressed more fully in our answers to Q1 and Q2 in section 4.

2.1.3 It follows from our stated position on the status of the human embryo that we would not accept the creation of embryos as a source of donated tissue, for any purpose, irrespective of the stage at which the tissue was used.

2.1.4 For reasons discussed below, we do not accept manipulation of the human germ line (which would include the mitochondrial genes of an embryo), for any purpose.

2.2 Reproductive cloning

2.2.2 A defence of the argument against reproductive cloning might seem hardly to be necessary. The overwhelming consensus of opinion, both in the scientific community and generally, has hitherto been firmly against cloning and germ line gene therapy. But in the recent debate following from the birth of Dolly the sheep it is beginning to be suggested that human cloning could be of positive benefit to humanity. Indeed some go further. An American lawyer suggests that to deny infertile people the right to be cloned is 'tantamount to forced sterilization' (1), and that cloning must be regarded as a constitutional right in the United States (2).

2.2.3 While open support for cloning is still limited, we have seen how quickly opinion may be swayed by emotional appeals to the rights of infertile couples, and exaggerated claims about the likely benefits of research. Those with a principled objection to human reproductive cloning should therefore waste no time in spelling out the nature of that objection, and we intend to take this opportunity to do so.

2.3 Altering the germ line

2.3.2 The degree of control implied by cloning by nuclear transfer alone should not be underestimated. A woman would not necessarily be restricted to cloning herself or her sexual partner. A small tissue sample from any adult is all that is required. It is possible to envisage certain individuals offering themselves as cloning 'templates', for a small fee, based upon their looks and the results of psychological tests. This would enable a prospective 'parent' to browse through a catalogue of adult templates and in the expectation of giving birth to a child with looks very close to, and mental abilities fairly close to, the selected model.

2.3.4 Cloning by nuclear transfer alone might still seem to allow control over the genome only with a fairly broad brush - the clone must be genetically identical to a previously existing individual. This represents 100% accuracy, but limited specificity. But if the pool of potential clonees is large enough, the restriction becomes less important, and the scope for selecting required characteristics in the clone becomes considerable. This is why we consider the ethical problems of simple cloning to be essentially the same as that of genetic manipulation of embryos.

2.3.5 Since the issues of cloning and of germ line genetic manipulation are so closely linked, and since the ethical concerns raised by them are often identical, we intend to treat these issues together.

2.3.6 In the longer term it seems likely that artificial wombs will become possible. Since the problem we are considering is essentially that of increasing control over all aspects of human reproduction, we consider this possibility also.

2.4 Status of a human clone

2.4.2 A clone of an adult human being would be a copy of the adult only to the extent of being genetically identical. It would certainly be no more similar to the clonee, in appearance or personality, than an identical twin. (Since the clone would not share its mitochondrial DNA, womb, or childhood environment with the clonee he/she might be expected to be rather less similar than an identical twin). A clone would be born in the normal way and require to be raised as a normal human child. A clone would not be, in itself, any different from any other human being. (Unless, of course, radical genetic alteration had been attempted).

2.4.3 Since we do not hold to a naive genetic determinism, we do not share some stereotypical concerns about cloning for instance that it might become possible to clone Adolf Hitler or Saddam Hussain. Even if this were done, there is no reason to believe the resulting child would grow up to be an evil dictator. He would have no inherited knowledge of the life or deeds of the clonee and, if he had a radically different upbringing and early environment, could perhaps turn out to be a model citizen. Even if the clone grew up with similar moral deficiencies, lacking the particular circumstances that gave rise to Hitler and Saddam, he would be more likely to end up as a petty office dictator than a global menace.

2.4.4 Similarly, a man who wished to be cloned in order that his own life would continue after his death would almost certainly be disappointed. He would raise a child that would be his genetic double, but that would very likely (as children do) grow up with different interests, different politics, and his own ideas about how to conduct his life.

2.4.5 We hold that a clone, if one were ever produced, whether legally or illegally, would certainly have to be accorded the same rights as any other human being. It would be an individual in its own right, not an adjunct to or chattel of the clonee. Nor would the clone be the child of the clonee. (The problems associated with a clonee wishing to act as the parent of a clone are discussed below).

2.4.6 Our concerns about cloning do not arise from the nature of a clone itself (except for some very long term considerations which we discuss below), but from the effects upon the clones, and upon society, of turning the parent child relationship into that of manufacturer to product.

2.5 Born Equal

2.5.2 In the evolving democratic tradition of the western world the ideal of equality between human beings has assumed a fundamental importance. It is perhaps most memorably stated in the American Declaration of Independence: "We hold these truths to be self-evident, that all men are created equal . " and is affirmed in the Universal Declaration of Human Rights: "All human beings are born free and equal in dignity and rights".

2.5.3 Equality of dignity and rights does not imply equality of capabilities. But it is hard to see how equality of dignity and rights could survive the fact of certain human beings being created according to the specifications of others.

2.5.4 We reiterate that we do not hold to a simplistic genetic determinism. But to determine a person's genome is, to a large extent, to determine some of the major constraints within which their capabilities and aptitudes, both physical and mental, will lie. More so if (as would presumably be the case) the instigators of the cloning also have control of the child's upbringing.

2.5.5 It is inevitably difficult to assess how society might develop if this technology were to become available. So we will discuss a number of scenarios in order to demonstrate the reasons for our concerns.

2.6 Brave New World

2.6.2 Aldous Huxley does not in fact describe slavery in the ordinary sense. The people of the Brave New World said, and believed, that they were free. The lower castes did manual labour because they were not capable of doing, or wanting to do, anything else. People were pretty much free within their capabilities. It was the capabilities themselves that were constrained.

2.6.3 On a crude utilitarian analysis you can not fault this kind of society. Happiness is maximized. It is better to have stupid, happy road sweepers that clever, frustrated ones. But the conclusion most people draw is that these people were not truly free. (Freedom is, of course, a non-utilitarian value).

2.6.4 So the problem we are faced with in the Brave New World scenario is not that someone might breed an army of slaves (which is illegal), but that they might breed people who, even when given the full panoply of democratic rights, are incapable of taking advantage of them. That their capabilities have been so constrained that, even when free to choose what to do, they are almost certain to make the choices that those who created them intended them to make.

2.6.5 Some contend that what is obnoxious about the Brave New World scenario is simply that reproduction is controlled by the state. In order to explore these issues we should like to construct a similar scenario in which the cloning is carried out by a rich private individual. For the purposes of this example we postulate not only cloning, but an artificial womb.
Joe is educationally subnormal. He lives in an institution near the factory where he works. He is bright enough to perform simple tasks well. He is friendly with people he knows, but suspicious of strangers. He shows great deference to those he regards as his superiors. He likes routine, and gets upset by any changes.

An industrial tycoon, Mr Rich, ascertains that Joe's condition is genetic. He obtains Joe's consent and pays him to use his cells to produce clones in artificial wombs. Mr Rich contends that he is the legal parent of all these children, on the basis that he created them as an exercise of his fundamental human right to to reproduce.

Of course, he will not mistreat the children or they will be removed by the state. He will employ professional staff to care for them, though no more, and no better qualified, than necessary. He will provide schooling suitable to their special needs. He will want to reinforce the mental traits he liked in Joe. Of course, these will not be entirely genetic, but a result of Joe's particular experiences. But he knows the potential for those attitudes is there.

When old enough, the clones start work in the factory. Mr Rich has to abide by laws about working conditions and the minimum wage. But most workers choose to live in the factory village, and pay rent to Mr Rich, and shop in the company shop. They are all free to leave, free to get other jobs, live elsewhere, shop elsewhere. Quite likely some do. But are we surprised if most do not?
2.6.6 This scenario raises further questions about human freedom. Are the clones any less free than the original Joe? In terms of their legal rights, no. Is the way they were raised an infringement of their freedom? Perhaps. But the right of religious cults to raise their children in near isolation and with odd beliefs is generally protected. The clones have been treated no worse.

2.6.7 In terms of genetics they are identical to Joe (except for mitochondrial DNA). So how can their genetics be an issue? The statement that human beings are 'born equal' never meant that we all have the same capabilities. We are all constrained by our genetics and environment. But freedom in the political sense means freedom from constraints imposed by other human beings, not freedom from natural constraints. If you go for a walk in the woods and get to a river you can't cross that restricts your ability to go on, but not your freedom. A fence restricts your freedom (whether justifiably or not).

2.6.8 We think this justifies the common sense view that people produced in the Brave New World scenario are not truly free. We all operate within natural constraints. But in the case of cloned or genetically engineered people, those constraints have been placed by others. Joe was a free man. But his clones are not.

2.6.9 But how, it may be asked, can it be a violation of a person's rights to bring them into existence? It would not be said (at any rate by us) that a mildly retarded person such as Joe would be better off not to have existed. Why should that not apply to his clones also? Indeed this question has already been raised by the Human Fertilisation and Embryology Act, which requires that "A woman shall not be provided with treatment services unless account has been taken of the welfare of any child who may be born as a result of the treatment . " (13.-(5)). Does this imply that, in some circumstances, the welfare of a child might require it not to exist?

2.6.10 This interpretation is indeed paradoxical. But we do not hold that a person's rights can be violated by bringing them into existence. We resolve the paradox by noting that not every wrong need be a violation of a right. To use technology to bring into existence a child with deliberately imposed disadvantages would be wrong, not because it violated the rights of the child (which would not exist otherwise) but because it would be an offence against human dignity.

2.6.11 The offence arises because the capabilities of the child have been constrained by those who decided upon its characteristics before it was created. This not a power that any human being should have over another. It follows that to create a child with enhanced capabilities is equally an affront to human dignity. This is surely one reason why we are repelled by the idea of breeding a master race. It is not, after all, that we do not like blue-eyed blond-haired, intelligent, beautiful people. It is that we recognize the affront in presuming to determine in advance people's genetic characteristics.

2.6.12 This is essentially the point made by one formulation of Kant's categorical imperative: that a person should never be used solely as a means to an end, but always as an end in itself. The degree of control exercised over the creation of a clone makes this impossible.

2.6.13 The Brave New World scenario, and our variation upon it, requires not only cloning but artificial wombs. (Since it does not seem plausible that Mr Rich would persuade hundreds of women to take part in his scheme). If cloning is followed by normal pregnancy does that not reduce the potential for abuse? We answer that point in two ways. First, that artificial wombs seem no more outlandish today than human cloning did ten years ago. If cloning were to come to be accepted as a part of the human right to reproduce, artificial wombs would logically come into the same category. Second, and more importantly, that the essential objection still stands. The degree of power that those creating a clone exercise over that clone is unacceptable. This is so even if the clone is borne by a woman who intends to raise it as her own child, and it applies whether or not simple cloning is employed, or whether genetic manipulation is used.

2.7 Improving the race

2.7.3 We consider that while people have the right to have children, and to raise them as they see fit with minimal interference from the state, they do not have the right to exercise control over their genetics.

2.8 Parents and children

2.8.2 We would recommend extreme caution about using the terms parent and child to refer to a clonee and a clone. Genetically the clone is a twin of the clonee, not his or her child. Since the clonee is genetically neither the mother nor the father of the clone we doubt that the term parent is applicable. A clone has been created asexually and does not have parents in any normal sense. Your clone is simply your clone. This is not a relationship that has ever existed, and the usual terminology is not applicable.

2.8.3 All one can truly say is that it that the clone is a manufactured creature without any definable family relationships. Who are its grandparents, siblings and cousins? If a woman gives birth to her own clone, is her father the clone's grandfather? Genetically he is her father too. This need not prevent a clone being accepted into an extended family, as indeed many genetically unrelated children are. But the clone's lack of relationships that we all take for granted must be considered significant. Family relationships based upon kinship are the basis of our personal lives and of society. Medical technologies which sever those ties or treat them as of no consequence must in our view always be questionable.

2.8.4 Those who advocate the creation of a clone in order to fulfil the desire of a clonee to have a child gloss over this point. The term 'parent' is used in these cases rhetorically and aspirationally simply because that is what the clonee intended by being cloned. It is not an objective fact. The term 'older sister' could be used with greater plausibility. The fact that the clonee is able to define this relationship however she sees fit is surely further evidence of its abusive nature.

2.8.5 What are the implications of a clone being raised by the clonee alone, or by a couple, one of whom is the clonee? We now consider a scenario in which cloning is available, but without genetic manipulation.
A couple with distinguished musical careers wish their own child to become a musician. But what if the child does not inherit their talents? In order to avoid the genetic lottery they arrange for the woman to bear a clone of herself, or the man, or another world class musician. In that way they ensure the child has the genetic potential for musical talent.
2.8.6 Is the position of this child any different from that of a child that the couple might bear naturally? We think so. In the normal way of things, parents can encourage a child in a particular direction, but ultimately have to accede to the child's own wishes. When the child says "I don't like music and I am no good at it - I want to be a scientist" the parents have to accept it. For a clone the parent has an unanswerable response: "I know you have the capability because you have the same genes as me (or Yehudi Menuin or whatever). You have no aptitude for science. Get back to your violin practice". Even if this is not true (and it may not be) the child is not in a good position to answer back. If the parent was not markedly predisposed to react in that way, it is hard to see why they would have wished to produce a clone in the first instance.

2.8.7 We hold that parents have a duty to love their children unconditionally, whatever their abilities. Cloning goes directly against that. One can hope that ones children will have certain abilities and that they will choose to lead their lives in a particular way. But this is not something that a parent can demand or seek to ensure.

2.8.8 The point here is not whether a clone is simply a copy of clonee. (It would not be). The point is rather that it would be intolerable to have been created for that reason.

2.8.9 Ordinary sexual reproduction imposes a kind of balance of power between parents and offspring. Parents have enormous control over the environment in which a child is raised - but almost none over the child's genetics. We believe that to give parents untrammelled power over their offspring's genes is not an extension of freedom but a denial of it.

2.9 The long term

2.9.2 If, as has been proposed, cloning is adopted as a means of infertile people producing a child, then in cases where the cause of infertility is genetic, the clone too will be infertile. This implies that the only means the clone will have to reproduce will be by cloning also. Unlike naturally occurring twins, there will be no limit to the number of identical individuals eventually produced. This has a number of implications.

2.9.3 It is known that genetically homogeneous populations are susceptible to epidemics of disease. (Indeed this is thought to be one reason why sexual reproduction is advantageous (4)). If a large proportion of the population came to be made up of a small number of identical clones, this could become significant.

2.9.4 Why should clones ever become very common? It is generally accepted that asexual reproduction is twice as efficient as sexual reproduction, in the sense that it passes on all of an individuals genes to the next generation, rather than just half of them (5). Suppose a woman has two children, and each of them has two children, and so on. After ten generations she would have 1024 descendants. If this was achieved through sexual reproduction, each will have 1/1024 of her genes: each is descended from 1023 other people of her generation. This is the break-even point for sexual reproduction. But if she and all her descendants were clones, all would be genetically identical to the original woman. She would have increased her representation in the gene pool by a factor of one thousand in just ten generations. And that is without having any more children than average.

2.9.5 Biologists believe that when a mutation for parthenogenesis (natural cloning) occurs in a sexually reproducing species, the clone will, by virtue of this reproductive advantage, swamp the sexually reproducing population. There are species consisting entirely of a single clone in which this is believed to have happened.

2.9.6 What could prevent this? The answer, in general, is that the clone will be kept in check by outbreaks of disease, to which the genetically differing sexual population will be more resistant (4). In a human population, using medical cloning, other possibilities arise. A woman who could reproduce only by cloning might well marry and produce a clone of herself and a clone of her husband, instead of two clones of herself. So we do not predict a doomsday scenario. We do say that the full implications of creating an entirely new means of human reproduction should be fully understood.

2.9.7 Each clone, that itself reproduces through cloning, is effectively a new sub-species. The clones would be otherwise normal, and there is no reason to suppose members of a clone would choose to live together in a separate community, and take charge of their own reproduction. But they might. If they did, how would this fledgeling sub-species evolve? It seems likely that human social relations, and even moral instincts, arise in part through kin selection (6). In the long term, there is no reason why these instincts should remain the same in a population that does not reproduce sexually. To go further than this would be enter the realm of science fiction. We might postulate the evolution of human populations with a social structure akin to that of an ants nest. We simply observe that the long term implications are even more difficult to predict than the short term problems.

When The World Stopped

Civilisation is a system. It should now be very obvious to people, how interconnected and interdependent our socioeconomic system is and how fragile that system has become. This is why I have tried to promote systems thinking in our polarised society. A society that is saturated with ideologues of all stripes that promote reductive thinking. In my article on Gynocentrism And The Demographic Implosion Of Western Civilisation 1 , I wrote about the precarious social and economic state of Western civilisation. The current pandemic has simply just exposed the rot hidden underneath the veneer of debt laden decadence I wrote about in that article. Like a storm exposing the fragility of a terminate infested house, this pandemic is demonstrating how fragile our modern socioeconomic system is to a serious, but in historical terms a relatively minor pandemic (compared to the Spanish flu, Smallpox and the Black Death, that killed millions more than this virus ever will). Coronavirus is merely the straw that is breaking the camel’s back and demonstrating just how exposed we have let ourselves become.

Yes the pandemic is serious, but this is not the first time our world has faced a major pandemic and it will not be the last. It is however the first time our modern society has faced such a challenge. Since World War 2, modern society has had 75 years of relatively uninterrupted peace and prosperity. We have become complacent over time in the absence of major hardship and have lost focus on what really matters and what is really important. There has been a gradual erosion of long term thinking and planning politically, socially and economically. We have been living in a bubble world of safety and prosperity. This bubble world we have created, has fostered all kinds of crazy delusional ideological thinking and unsustainable elements to thrive in our culture and institutions. Coronavirus is a needle to our bubble world.

We have lost touch with reality and this society has forgotten that pandemics and other major events (like major volcanic super eruptions which can and do have devastating global effects, a major meteorite strike, or a one in two hundred year solar storm like the Carrington event of 1859 that could wipe out most of our electrical grid and satellite network) do in fact occur and have to be planned, prepared and accounted for accordingly. These things don’t just happen in movies like Contagion. We have become blasé about the long-term impacts of current decisions on our future and the sustainability of what we are collectively doing socially and economically. We have had little regard for how well prepared we are to handle external social and economic shocks. We can see that just by looking at our reckless reliance on debt to drive our economy and on our inaction to address fatherlessness and the destruction of the family and all the downstream social and economic impacts that has on our society. There are many other examples of this recklessness and cavalier attitude of course that I could cite.

Short-term thinking, apathy over the future consequences for current political, social and economic decisions and societal decadence, have all crept into our collective psyche. Older generations lived through the Spanish flu, two world Wars and the Great Depression. It was understood from the lessons learned from those hardships, that society had to plan and invest over the long term and not just think about winning the next election or focusing on short-term profit. These lessons have gradually been forgotten and we have been living off the fruits of past generations for decades.

The ideological claptrap of modern feminism and other ideologies, has swelled in this cultural memory loss of past hardships and in the absence of any relative existential threat to civilisation. They have thrived like parasites off a golden age of peace and prosperity. How relevant now is ideological feminism? How relevant are gender quotas in the middle of this major pandemic? How relevant is manspreading, mansplaining and sexist air-conditioning? How useful are feminists in this crisis? If there is a good thing about the Coronavirus it is this- It is forcing our “woke” society and our ideologically infested institutions to finally confront reality, put facts before feelings and identify what actually matters. The importance of border control should now be quite obvious, even to the most radical ideological idiots in our society. It is not xenophobic to want secure borders. The time for ideological bullshit is now over and it is now time for society to set its priorities straight.

The impact of this virus represents a stress test for our modern socioeconomic system. Civilisation has gone through far worse. We have survived pandemics, major disasters, wars, famine, recessions and depressions before. Millions and millions have died in some cases and society still found a way to go on. We were able to survive these periods because past generations lived and died by their values and worked together in a cooperative manner and supported each other. They made sacrifices, were no nonsense pragmatists and lived in reality and not in a woke ideological bubble. There was patriotism, values, meaning and purpose in what they did and in their culture. There was a relative absence of self-hatred, apathy, nihilism, fatalism and laziness. There was no nonsense about toxic masculinity or men being “obsolete”. The generations that lived through 1900 to 1950 in particular, were as tough as nails and we should attempt to emulate them today. How would they react to the present events? It would be water off a duck’s back for them. What we are going through is easy compared to what they faced. We can overcome this.

The reason I have focused on men’s issues in my writing, is because I understand how reliant this system is on men and on the family. Economic shocks can have very big effects on society, but if society has a strong social structure, it can withstand such hardship. The epidemic of fatherlessness and the breakdown of the family, does nothing but multiply the risk factor of social cohesion collapsing in the event of a crisis such as this by orders of magnitude. The economic impact of the boy crisis in education and fatherlessness, does nothing but substantially increase the fragility of our economic system to shocks like this pandemic.

As I mentioned before, everything is interconnected. Protecting the family, protecting fatherhood and addressing the needs of men and boys, is not just about looking after men, it is about ensuring our society is strong and has the integrity to withstand times of hardship like this pandemic. When we neglect men and boys, we weaken society and we magnify the risk factors that we will fall apart in the event of a societal shock or crisis. The social and economic effects of this pandemic will be felt not just for a few months, but for decades. The world has now changed in ways we are yet to even fully comprehend. There will be no returning to normal after the pandemic is gone. There is too much debt and too much economic and social degradation already in the system for a full recovery back to the pre-Corona status quo. We have not experienced a disruption on this scale since World War 2 and I would encourage people to explore what past generations did to cope with the hardships they experienced and what followed such major events. We are living through something historic.

I understand that there is a great deal of fear and panic in society at the moment. It is rational to have some fear, but it is dangerous to become overwhelmed by it. It is important to try to identify the positives over the negatives and keep ourselves mentally balanced. We are all impacted and that includes me. There are some positives to consider- This crisis presents society with an opportunity to re-evaluate its priorities, to re-learn some old and important lessons and to reconnect with what really matters and set a new future. I have been saving my money for years, because I understood the need to store seeds for the winter and I could see that at some point there would be a crisis and I would need to protect myself. I am glad I have prepared myself for this crisis. I have made the decision not to have children, because I could see that society was moving in an unsustainable direction. There is a lesson from this pandemic for everyone to save for a rainy day, to prepare for the winter and to hope for the best, but plan for the worst. I live my life that way- Cautiously optimistic but pessimistically prepared.

With the lessons we learn from our hardships, we will have an opportunity in the crisis and beyond it, to fundamentally transform our society into something far bigger, better and stronger than before. History shows that society can rebound very strongly after times of hardship. The renaissance and enlightenment followed the Black Death. Huge technological and social transformations followed World War Two. This crisis could become a positive inflection point in history. Alternatively if we succumb to fear and panic, we could descend into a new dark age and a period of totalitarian governance. It all comes down to how we collectively choose to respond to this crisis. Our future is in our hands.

This crisis is an opportunity for society to reflect on its unsustainable trajectory, to relearn valuable lessons and to undertake major transformative change. Our society is way overdue for a major reset and a fundamental restructure socially and economically. At the end of this crisis there will be opportunities for our society to do exactly that. A society that runs off unsustainable levels of debt, runaway gynocentrism 2 and numerous other unsustainable practices and activities, has a finite lifespan. If it was not Coronavirus that triggered this social and economic crisis, it would have been something else. We have to confront reality sooner or later.

The best antidote to fear is to work cooperatively and to focus on what is working and on developing a plan and solutions to get society through this crisis and back on track once this crisis has ended. Don’t succumb to fear. Instead spend this time reflecting on what matters most, learning from hardship and on harnessing the opportunities to ensure your future and societies future. I would like people to watch this video 3 with renowned physician and addiction expert Dr. Gabor Mate, on the social and psychological effects of this pandemic. Dr. Mate raises some important insights that are worth sharing and for us all to reflect on. We can either succumb to the destructive death spiral of fear and descend into mob violence over trivial things like toilet paper, or we can rally together in a united effort to fight for our own future and set an example for others to follow and live by. This is a time where we either choose to live by values, or die from nihilism and fatalism. Are we going to rise up to the challenge as past generations did, or are we going to succumb to fear and violence? Our choice.
In the words 4 of US President Franklin D. Roosevelt-

“The Only Thing We Have To Fear Is Fear Itself”

In his inauguration speech during the Great Depression, Franklin Roosevelt also spoke about the necessity of speaking the truth frankly and boldly, of the importance of having vision and of respecting others and working together. There was no identity politics, no lies, no avoidance of reality and no ideological dogma in his speech. He was a true leader in every sense of the word. We should emulate that spirit. Society will not properly recover from this pandemic, unless we have the courage to confront the dark truths about our society and address social and economic realities we have ignored for far too long and are prepared to undertake major fundamental transformative change of our society.

“The greatest generation” 5 got through the Spanish Flu, the Great Depression and World War One and World War Two and they never gave up. We can overcome Coronavirus. We have a relatively minor challenge before us in comparison to what they faced. It is in our collective control to set our own future. Society needs strong men more than ever at this moment in time. Men have never been more valuable than they are right now. Men literally keep us all alive and God bless you for doing so.

Be bold, be strong, be courageous and take care. There is light beyond the dark.

Tuesday, July 28, 2020

The insidious problem of racism

Take a moment to seriously think about what is wrong with racism. If you're like most people, your answer will probably be that racism is bad because it's a form of prejudice, and prejudice is bad. This is not wrong, but it misses a much deeper, more insidious issue. The real problem with racism is that it is that it can be (and usually is) rationalized and those rationalizations can turn into self-fulfilling prophecies, which in turn causes racism to not only be rationalized, but rationally justifiable. It's a vicious cycle that leads otherwise virtuous people to unwittingly contribute to great evils.

Here's an example: professional basketball players are disproportionately black by an enormous margin. Why? It would seem odd if this were a result of racial prejudice. Being a professional basketball player is not a menial job. It's a challenging, well-respected and well-compensated profession. Professional basketball players are role models. The stakes are high: if a team could gain a competitive advantage by hiring more white players they would surely do so. So it seems more likely that there is actually some kind of causal influence that results in black skin being correlated with basketball skill.

The obvious candidate for this kind of causal influence is that black people are taller than white people. Being tall presents an obvious advantage if you're a basketball player. I was convinced that this had to be the answer, but it's not. It turns out that, on average, black people are actually shorter than white people. (The source data is here.) So there goes that theory.

There could be some other physical trait that is linked to black skin that provides a competitive advantage in basketball. Black people also dominate in other sports, like running. Maybe there's some biological factor that makes blacks faster than whites, or able to jump higher, and that produces a competitive advantage in basketball.

But there is another, much more insidious possibility: maybe black dominance in basketball is not a physical advantage, but a cultural one. Maybe blacks make better basketball players simply because as a group they happen to spend more time playing basketball. And maybe the reason they spend more time playing basketball is that other avenues of economic advancement are closed to them for one reason or another, and so basketball is seen as the only way out of the hood. So they play basketball.

Notice that it is not necessary for it to actually be true that non-basketball careers are closed to blacks to set this vicious cycle into motion. The mere perception that it is true is enough. If a black kid growing up in the hood believes that he's never going to be hired as an engineer then he could reach the perfectly rational (albeit possibly mistaken) conclusion that he should not spend his time studying math but should practice basketball instead. The result is a lot more black kids playing basketball, and doing it with much more seriousness and dedication, than white kids. And the result of that is that the best basketball players are overwhelmingly black simply because they've been working at it harder than whites. And so the NBA team managers make the perfectly rational decision to hire black players because they are in point of actual fact better than whites. And then the next generation of black kids grows up seeing a lot of basketball-playing role models and very few engineering role models, and reach the perfectly rational conclusion that maybe they ought not to study engineering.

The mere belief that black people make better basketball players can actually cause them to be better basketball players in point of actual fact. It is, quite literally, a self-fulfilling prophecy. And the thing about self-fulfilling prophecies is that they are actually true!

Notice that all this can happen even if everyone is behaving rationally on good evidence and without any ill will on anyone's part. Less damaging forms of the same underlying dynamic are very common. Taxi cab drivers in Glendale, California are overwhelmingly Armenian. Restaurant owners in San Carlos are overwhelmingly Turkish. Cruise ship crew members are overwhelmingly Filipino (except for the senior officers). It's not because there is anything in the genes of Armenians that makes them better cab drivers, or the genes of Turks that makes them better resaurateurs, or the genes of Filipinos that makes them better sailors. It's purely a cultural dynamic of expectations playing against rational decision making to produce self-fulfilling prophecies.

But now, instead of basketball player or cab driver or sailor, consider a drug dealer.

Think about the mental image that popped into your brain when you read those words. I'll wager it was not a white guy in a suit and tie in the board room of a pharmacology company, though such a person is very much a drug dealer. The image that popped into your head was very likely a black man in a hoodie shuffling furtively on a street corner. And yet John Kapoor is every bit as much a drug dealer as El Chapo Guzman, and vastly more of a drug dealer than, say, Aron Tuff.

You have likely never heard of Aron Tuff. I hadn't until I started researching this post. Tuff was sentenced to life in prison without parole because police found a third of a gram of cocaine in his yard. It was his third strike. Compare that to Kapoor's five-year sentence for peddling massive quantities of opioids that caused tens of thousands of deaths. Part of the rationale for Kapoor's reduced sentence was his "philanthropy", notwithstanding that the money he used to engage in philanthropy came from dealing drugs. Vast quantities of drugs which killed tens of thousands of people.

There is no end to the ways in which the disparities between Kapoor's sentence and Tuff's can be rationalized. The drugs Kapoor sold were legal. The drugs that Tuff (allegedly) possessed (but did not sell) were illegal. Kapoor was a respected captain of industry, a job creator. Tuff was an addict with priors. All of these things are true. None of them have anything to do with race, at least not overtly. And yet, somehow the net result is that blacks get sent to prison for drug offenses a lot more than whites do.

This is the problem with racism: it's never just about the color of someone's skin. Skin color is always just a proxy for some other quality which actually justifies the racism. This goes all the way back to chattel slavery in the American South: blacks were not enslaved because they were black per se, they were enslaved because they were inferior. Skin color was just an indicator of the inferiority. Many slave owners believed in good faith at the time that they were actually doing blacks a favor by enslaving them. If you don't believe me, all you have to do is read this excerpt from the articles of secession of the state of Texas:

That sounds shocking today, but it wasn't shocking then. Millions of people passionately believed in the sentiment expressed in these words. Tens of thousands literally fought and died for them. They sincerely believed they were the good guys.

Today the proxy quality that launches the vicious cycle is no longer genetic inferiority, it's something else. It's "making poor decisions" or whatever the fuck it is, it doesn't matter. What matters is that the structure of the argument and the resulting social dynamic is exactly the same as it was in 1861: black skin is taken to be a reliable proxy for some other quality --the ability to play basketball, a propensity to criminality-- and that belief becomes a self-fulfilling prophecy and hence actually true. Everyone believes in good faith (indeed, correctly!) that they are acting rationally and on good evidence! And yet the result is catastrophic.

So what do we do about it? After all, rationality got us in to this mess, so how can it possibly get us out? Well, first we have to agree that it's a mess. Not everyone does. There is a school of thought that says that everything is basically hunky-dory, at least on a systemic level. Slavery is gone. Jim Crow is gone. Any remaining disparities must therefore be a result of individual choices because the playing field has now been leveled. If there are problems they should be dealt with on an individual level. If someone breaks the law, they go to jail. Eventually the transgressors will figure out that it is better for them to hew to the social order, so all we need to do is send enough troops to quell the riots and sooner or later this will all sort itself out. Now, excuse me while I mix myself a martini and get my kids ready to go to their private school.

There are actually people who think that we've already gone overboard in our attempts to address racial issues in the U.S. There is a small but significant contingent who believes that legally enforced segregation, a return to separate-but-equal, is actually the Right Answer. If you think these people can simply be ignored you have not been paying attention. The Trump administration is actively courting these people. If you are one of those people who believes that Donald Trump doesn't have a racist bone in his body, well, I have a bridge you might be interested in buying.

Personally, it seems to me that we tried segregation for about 100 years and as far as I'm concerned it was not a good outcome, and I'm white. Like I said in my earlier post on this topic, I am the beneficiary of the current system. The expectations that turn into self-fulfilling prophecies have worked very much in my favor. I'm a white male, and so everyone expected me to grow up to be successful, and lo and behold I grew up to be successful. I was there for this entire process and so I can tell you that this was not because of any extraordinary effort on my part. I totally coasted to my success. I figured out how to game the system in middle school, and I've been doing it ever since. I have a very impressive-looking resume, but if you look carefully none of it actually reflects any extraordinary accomplishment on my part. Yes, I worked for NASA for fifteen years. Yes, that sounds impressive. But the reason I worked for NASA for 15 years is because I happened to be in graduate school when my advisor got a job offer, and he took me with him. The reason I was in grad school is because I was too lazy to get a real job. The reason I was able to go to grad school in the first place is because the government gave me a fellowship, and before that the university I attended gave me a scholarship, and all that happened because I got good grades. And the reason I was able to get good grades is that I grew up in a quiet house within walking distance of the country club (the neighborhood I grew up in was literally called Country Club Estates!) where there was not a basketball court to be found. Tennis. Golf. A swimming pool where waiters would bring me club sandwiches that I didn't have to pay for. It was fucking awesome. And it was only possible because I was white. There were no black people in the Country Club Estates. Not in the 1970s. Not in Tennessee.

Things are certainly better today. My parents still live in the house I grew up in, and today their next-door neighbors are black, so maybe this will all sort itself out in the fullness of time. But at the same time the Supreme Court casually disenfranchises a million ex-felons in Florida, who are, of course, disproportionately black. The President of the United States calls white supremacists "fine people" and sends secret police to arrest people carrying Black Lives Matter banners. An American Senator defends chattel slavery as a "necessary evil". Black people are killed by police at a much higher rate than white people. I don't have to worry about any of this because I'm white. And this gnaws at my soul.

No human being should grow up believing that they will be judged by the color of their skin, and they certainly should not grow up being correct in that belief, but that is today's reality. The first step to fixing this is to persuade people that it needs fixing, and it needs fixing now. We've been fucking around for 400 years. Enough. The recently deceased John Lewis said it better than I can: