Gene-centered view of evolution

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The gene-centered view of evolution, gene's eye view, gene selection theory, or selfish gene theory holds that adaptive evolution occurs through the differential survival of competing genes, increasing the allele frequency of those alleles whose phenotypic trait effects successfully promote their own propagation. [1] [2] [3] The proponents of this viewpoint argue that, since heritable information is passed from generation to generation almost exclusively by DNA, natural selection and evolution are best considered from the perspective of genes.

Contents

Proponents of the gene-centered viewpoint argue that it permits understanding of diverse phenomena such as altruism and intragenomic conflict that are otherwise difficult to explain from an organism-centered viewpoint. [4] [5]

The gene-centered view of evolution is a synthesis of the theory of evolution by natural selection, the particulate inheritance theory, and the non-transmission of acquired characters. [6] [7] It states that those alleles whose phenotypic effects successfully promote their own propagation will be favorably selected relative to their competitor alleles within the population. This process produces adaptations for the benefit of alleles that promote the reproductive success of the organism, or of other organisms containing the same allele (kin altruism and green-beard effects), or even its own propagation relative to the other genes within the same organism (selfish genes and intragenomic conflict).

Overview

The gene-centered view of evolution is a model for the evolution of social characteristics such as selfishness and altruism, with gene defined as "not just one single physical bit of DNA [but] all replicas of a particular bit of DNA distributed throughout the world".[ verify ]

Acquired characteristics

John Maynard Smith John Maynard Smith.jpg
John Maynard Smith

The formulation of the central dogma of molecular biology was summarized by Maynard Smith:

If the central dogma is true, and if it is also true that nucleic acids are the only means whereby information is transmitted between generations, this has crucial implications for evolution. It would imply that all evolutionary novelty requires changes in nucleic acids, and that these changes – mutations – are essentially accidental and non-adaptive in nature. Changes elsewhere – in the egg cytoplasm, in materials transmitted through the placenta, in the mother's milk – might alter the development of the child, but, unless the changes were in nucleic acids, they would have no long-term evolutionary effects.

Maynard Smith [8]

The rejection of the inheritance of acquired characters, combined with Ronald Fisher the statistician, giving the subject a mathematical footing, and showing how Mendelian genetics was compatible with natural selection in his 1930 book The Genetical Theory of Natural Selection . [9] J. B. S. Haldane, and Sewall Wright, paved the way to the formulation of the selfish-gene theory.[ clarification needed ] For cases where environment can influence heredity, see epigenetics.[ clarification needed ]

The gene as the unit of selection

Richard Dawkins Richard Dawkins Cooper Union Shankbone.jpg
Richard Dawkins

The view of the gene as the unit of selection was developed mainly in the works of Richard Dawkins, [10] [11] W. D. Hamilton, [12] [13] [14] Colin Pittendrigh [15] and George C. Williams. [16] It was popularized by Dawkins in his book The Selfish Gene (1976). [1]

According to Williams' 1966 book Adaptation and Natural Selection ,

[t]he essence of the genetical theory of natural selection is a statistical bias in the relative rates of survival of alternatives (genes, individuals, etc.). The effectiveness of such bias in producing adaptation is contingent on the maintenance of certain quantitative relationships among the operative factors. One necessary condition is that the selected entity must have a high degree of permanence and a low rate of endogenous change, relative to the degree of bias (differences in selection coefficients).

Williams, [16] 1966, pp. 22–23

Williams argued that "[t]he natural selection of phenotypes cannot in itself produce cumulative change, because phenotypes are extremely temporary manifestations." Each phenotype is the unique product of the interaction between genome and environment. It does not matter how fit and fertile a phenotype is, it will eventually be destroyed and will never be duplicated.

Since 1954, it has been known that DNA is the main physical substrate to genetic information, and it is capable of high-fidelity replication through many generations. So, a particular gene coded in a nucleobase sequence of a lineage of replicated DNA molecules can have a high permanence and a low rate of endogenous change. [17]

In normal sexual reproduction, an entire genome is the unique combination of father's and mother's chromosomes produced at the moment of fertilization. It is generally destroyed with its organism, because "meiosis and recombination destroy genotypes as surely as death." [16] Only half of it is transmitted to each descendant due to independent segregation.

And the high prevalence of horizontal gene transfer in bacteria and archaea means that genomic combinations of these asexually reproducing groups are also transient in evolutionary time: "The traditional view, that prokaryotic evolution can be understood primarily in terms of clonal divergence and periodic selection, must be augmented to embrace gene exchange as a creative force." [18] [19]

The gene as an informational entity persists for an evolutionarily significant span of time through a lineage of many physical copies. [2] [20]

In his book River out of Eden , Dawkins coins the phrase God's utility function to explain his view on genes as units of selection. He uses this phrase as a synonym of the "meaning of life" or the "purpose of life". By rephrasing the word purpose in terms of what economists call a utility function, meaning "that which is maximized", Dawkins attempts to reverse-engineer the purpose in the mind of the Divine Engineer of Nature, or the utility function of god. Finally, Dawkins argues that it is a mistake to assume that an ecosystem or a species as a whole exists for a purpose. [21] [note 1] He writes that it is incorrect to suppose that individual organisms lead a meaningful life either; in nature, only genes have a utility function – to perpetuate their own existence with indifference to great sufferings inflicted upon the organisms they build, exploit and discard. [note 1]

Organisms as vehicles

Genes are usually packed together inside a genome, which is itself contained inside an organism. Genes group together into genomes because "genetic replication makes use of energy and substrates that are supplied by the metabolic economy in much greater quantities than would be possible without a genetic division of labour." [23] They build vehicles to promote their mutual interests of jumping into the next generation of vehicles. As Dawkins puts it, organisms are the "survival machines" of genes. [1]

The phenotypic effect of a particular gene is contingent on its environment, including the fellow genes constituting with it the total genome. A gene never has a fixed effect, so how is it possible to speak of a gene for long legs? It is because of the phenotypic differences between alleles. One may say that one allele, all other things being equal or varying within certain limits, causes greater legs than its alternative. This difference enables the scrutiny of natural selection.

"A gene can have multiple phenotypic effects, each of which may be of positive, negative or neutral value. It is the net selective value of a gene's phenotypic effect that determines the fate of the gene." [24] For instance, a gene can cause its bearer to have greater reproductive success at a young age, but also cause a greater likelihood of death at a later age. If the benefit outweighs the harm, averaged out over the individuals and environments in which the gene happens to occur, then phenotypes containing the gene will generally be positively selected and thus the abundance of that gene in the population will increase.

Even so, it becomes necessary to model the genes in combination with their vehicle as well as in combination with the vehicle's environment.

Selfish-gene theory

The selfish-gene theory of natural selection can be restated as follows: [24]

Genes do not present themselves naked to the scrutiny of natural selection, instead they present their phenotypic effects. [...] Differences in genes give rise to differences in these phenotypic effects. Natural selection acts on the phenotypic differences and thereby on genes. Thus genes come to be represented in successive generations in proportion to the selective value of their phenotypic effects.

Cronin, 1991, p. 60

The result is that "the prevalent genes in a sexual population must be those that, as a mean condition, through a large number of genotypes in a large number of situations, have had the most favourable phenotypic effects for their own replication." [25] In other words, we expect selfish genes ("selfish" meaning that it promotes its own survival without necessarily promoting the survival of the organism, group or even species). This theory implies that adaptations are the phenotypic effects of genes to maximize their representation in future generations. [note 1] An adaptation is maintained by selection if it promotes genetic survival directly, or else some subordinate goal that ultimately contributes to successful reproduction.

Individual altruism and genetic egoism

The gene is a unit of hereditary information that exists in many physical copies in the world, and which particular physical copy will be replicated and originate new copies does not matter from the gene's point of view. [20] A selfish gene could be favored by selection by producing altruism among organisms containing it. The idea is summarized as follows:

If a gene copy confers a benefit B on another vehicle at cost C to its own vehicle, its costly action is strategically beneficial if pB > C, where p is the probability that a copy of the gene is present in the vehicle that benefits. Actions with substantial costs therefore require significant values of p. Two kinds of factors ensure high values of p: relatedness (kinship) and recognition (green beards).

Haig, [23] 1997, p. 288

A gene in a somatic cell of an individual may forgo replication to promote the transmission of its copies in the germ line cells. [note 1] It ensures the high value of p = 1 due to their constant contact and their common origin from the zygote.

The kin selection theory predicts that a gene may promote the recognition of kinship by historical continuity: a mammalian mother learns to identify her own offspring in the act of giving birth; a male preferentially directs resources to the offspring of mothers with whom he has copulated; the other chicks in a nest are siblings; and so on. The expected altruism between kin is calibrated by the value of p, also known as the coefficient of relatedness. For instance, an individual has a p = 1/2 in relation to his brother, and p = 1/8 to his cousin, so we would expect, ceteris paribus , greater altruism among brothers than among cousins. In this vein, geneticist J. B. S. Haldane famously joked, "Would I lay down my life to save my brother? No, but I would to save two brothers or eight cousins." [26] However, examining the human propensity for altruism, kin selection theory seems incapable of explaining cross-familiar, cross-racial and even cross-species acts of kindness, to which Richard Dawkins wrote:

Lay critics frequently bring up some apparently maladaptive feature of modern human behaviour—adoption, say, or contraception [...] The question, about the adaptive significance of behaviour in an artificial world, should never have been put [...] A useful analogy here is one that I heard from R. D. Alexander. Moths fly into candle flames, and this does nothing to help their inclusive fitness [...] We asked ‘Why do moths fly into candle flames?’ and were puzzled. If we had characterized the behaviour differently and asked ‘Why do moths maintain a fixed angle to light rays (a habit which incidentally causes them to spiral into the light source if the rays happen not to be parallel)?’, we should not have been so puzzled.

Dawkins, [11] 1982, chapter 3

Green-beard effect

Green-beard effects gained their name from a thought-experiment first presented by Bill Hamilton [27] and then popularized and given its current name by Richard Dawkins who considered the possibility of a gene that caused its possessors to develop a green beard and to be nice to other green-bearded individuals. Since then, "green-beard effect" has come to refer to forms of genetic self-recognition in which a gene in one individual might direct benefits to other individuals that possess the gene. [note 1] Such genes would be especially selfish, benefiting themselves regardless of the fates of their vehicles. Since then, green-beard genes have been discovered in nature, such as Gp-9 in fire ants (Solenopsis invicta), [28] [29] csA in social amoeba (Dictyostelium discoideum), [30] and FLO1 in budding yeast (Saccharomyces cerevisiae). [31]

Intragenomic conflict

As genes are capable of producing individual altruism, they are capable of producing conflict among genes inside the genome of one individual. This phenomenon is called intragenomic conflict and arises when one gene promotes its own replication in detriment to other genes in the genome. The classic example is segregation distorter genes that cheat during meiosis or gametogenesis and end up in more than half of the functional gametes. These genes can persist in a population even when their transmission results in reduced fertility. Egbert Leigh compared the genome to "a parliament of genes: each acts in its own self-interest, but if its acts hurt the others, they will combine together to suppress it" to explain the relative low occurrence of intragenomic conflict. [32] [note 1]

Price equation

The Price equation is a covariance equation that is a mathematical description of evolution and natural selection. The Price equation was derived by George R. Price, working to rederive W. D. Hamilton's work on kin selection.

Advocates

Besides Richard Dawkins and George C. Williams, other biologists and philosophers have expanded and refined the selfish-gene theory, such as John Maynard Smith, George R. Price, Robert Trivers, David Haig, Helena Cronin, David Hull, Philip Kitcher, and Daniel C. Dennett.

Criticisms

The gene-centric view has been opposed by Ernst Mayr, Stephen Jay Gould, David Sloan Wilson, and philosopher Elliott Sober. An alternative, multilevel selection (MLS), has been advocated by E. O. Wilson, David Sloan Wilson, Sober, Richard E. Michod, [33] and Samir Okasha. [33]

Writing in the New York Review of Books , Gould has characterized the gene-centered perspective as confusing book-keeping with causality. Gould views selection as working on many levels, and has called attention to a hierarchical perspective of selection. Gould also called the claims of Selfish Gene "strict adaptationism", "ultra-Darwinism", and "Darwinian fundamentalism", describing them as excessively "reductionist". He saw the theory as leading to a simplistic "algorithmic" theory of evolution, or even to the re-introduction of a teleological principle. [34] Mayr went so far as to say "Dawkins' basic theory of the gene being the object of evolution is totally non-Darwinian." [35]

Gould also addressed the issue of selfish genes in his essay "Caring groups and selfish genes". [36] Gould acknowledged that Dawkins was not imputing conscious action to genes, but simply using a shorthand metaphor commonly found in evolutionary writings. To Gould, the fatal flaw was that "no matter how much power Dawkins wishes to assign to genes, there is one thing that he cannot give them – direct visibility to natural selection." [36] Rather, the unit of selection is the phenotype, not the genotype, because it is phenotypes that interact with the environment at the natural-selection interface. So, in Kim Sterelny's summation of Gould's view, "gene differences do not cause evolutionary changes in populations, they register those changes." [37] Richard Dawkins replied to this criticism in a later book, The Extended Phenotype, that Gould confused particulate genetics with particulate embryology, stating that genes do "blend", as far as their effects on developing phenotypes are concerned, but that they do not blend as they replicate and recombine down the generations. [11]

Since Gould's death in 2002, Niles Eldredge has continued with counter-arguments to gene-centered natural selection. [38] Eldredge notes that in Dawkins' book A Devil's Chaplain , which was published just before Eldredge's book, "Richard Dawkins comments on what he sees as the main difference between his position and that of the late Stephen Jay Gould. He concludes that it is his own vision that genes play a causal role in evolution," while Gould (and Eldredge) "sees genes as passive recorders of what worked better than what". [39]

See also

Notes

  1. 1 2 3 4 5 6 The use of anthropomorphic shorthand is a way of describing the action of a Darwinian unit of selection by attributing anthropomorphic qualities to the unit, such as purpose, selfishness etc. as well as actions such as promote, compete, etc. On a genetic level, units of selection do not possess these anthropomorphic attributes, and a proper description will describe the process of propagation and selection in mechanistic terms. The proper scientific description is often more wordy than the anthropomorphic shorthand, however, it should be used carefully to avoid misconceptions which may arise from extending the analogy too far. [22]

Related Research Articles

<span class="mw-page-title-main">Natural selection</span> Mechanism of evolution by differential survival and reproduction of individuals

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charles Darwin popularised the term "natural selection", contrasting it with artificial selection, which is intentional, whereas natural selection is not.

<span class="mw-page-title-main">Phenotype</span> Composite of the organisms observable characteristics or traits

In genetics, the phenotype is the set of observable characteristics or traits of an organism. The term covers the organism's morphology, its developmental processes, its biochemical and physiological properties, its behavior, and the products of behavior. An organism's phenotype results from two basic factors: the expression of an organism's genetic code and the influence of environmental factors. Both factors may interact, further affecting the phenotype. When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic. A well-documented example of polymorphism is Labrador Retriever coloring; while the coat color depends on many genes, it is clearly seen in the environment as yellow, black, and brown. Richard Dawkins in 1978 and then again in his 1982 book The Extended Phenotype suggested that one can regard bird nests and other built structures such as caddisfly larva cases and beaver dams as "extended phenotypes".

<i>The Selfish Gene</i> 1976 book by Richard Dawkins

The Selfish Gene is a 1976 book on evolution by the ethologist Richard Dawkins, in which the author builds upon the principal theory of George C. Williams's Adaptation and Natural Selection (1966). Dawkins uses the term "selfish gene" as a way of expressing the gene-centred view of evolution, popularising ideas developed during the 1960s by W. D. Hamilton and others. From the gene-centred view, it follows that the more two individuals are genetically related, the more sense it makes for them to behave cooperatively with each other.

Selfish genetic elements are genetic segments that can enhance their own transmission at the expense of other genes in the genome, even if this has no positive or a net negative effect on organismal fitness. Genomes have traditionally been viewed as cohesive units, with genes acting together to improve the fitness of the organism. However, when genes have some control over their own transmission, the rules can change, and so just like all social groups, genomes are vulnerable to selfish behaviour by their parts.

<i>The Extended Phenotype</i> 1982 book by Richard Dawkins

The Extended Phenotype is a 1982 book by the evolutionary biologist Richard Dawkins, in which the author introduced a biological concept of the same name. The book’s main idea is that phenotype should not be limited to biological processes such as protein biosynthesis or tissue growth, but extended to include all effects that a gene has on its environment, inside or outside the body of the individual organism.

Molecular evolution is the process of change in the sequence composition of cellular molecules such as DNA, RNA, and proteins across generations. The field of molecular evolution uses principles of evolutionary biology and population genetics to explain patterns in these changes. Major topics in molecular evolution concern the rates and impacts of single nucleotide changes, neutral evolution vs. natural selection, origins of new genes, the genetic nature of complex traits, the genetic basis of speciation, the evolution of development, and ways that evolutionary forces influence genomic and phenotypic changes.

Population genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure.

<span class="mw-page-title-main">Group selection</span> Proposed mechanism of evolution

Group selection is a proposed mechanism of evolution in which natural selection acts at the level of the group, instead of at the level of the individual or gene.

<span class="mw-page-title-main">Polymorphism (biology)</span> Occurrence of two or more clearly different morphs or forms in the population of a species

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<span class="mw-page-title-main">Index of evolutionary biology articles</span>

This is a list of topics in evolutionary biology.

In evolutionary biology, inclusive fitness is one of two metrics of evolutionary success as defined by W. D. Hamilton in 1964:

In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection.

<span class="mw-page-title-main">Unit of selection</span> Biological entity within the hierarchy of biological organization

A unit of selection is a biological entity within the hierarchy of biological organization that is subject to natural selection. There is debate among evolutionary biologists about the extent to which evolution has been shaped by selective pressures acting at these different levels.

Intragenomic conflict refers to the evolutionary phenomenon where genes have phenotypic effects that promote their own transmission in detriment of the transmission of other genes that reside in the same genome. The selfish gene theory postulates that natural selection will increase the frequency of those genes whose phenotypic effects cause their transmission to new organisms, and most genes achieve this by cooperating with other genes in the same genome to build an organism capable of reproducing and/or helping kin to reproduce. The assumption of the prevalence of intragenomic cooperation underlies the organism-centered concept of inclusive fitness. However, conflict among genes in the same genome may arise both in events related to reproduction and altruism.

The green-beard effect is a thought experiment used in evolutionary biology to explain selective altruism among individuals of a species.

Genetic assimilation is a process described by Conrad H. Waddington by which a phenotype originally produced in response to an environmental condition, such as exposure to a teratogen, later becomes genetically encoded via artificial selection or natural selection. Despite superficial appearances, this does not require the (Lamarckian) inheritance of acquired characters, although epigenetic inheritance could potentially influence the result. Waddington stated that genetic assimilation overcomes the barrier to selection imposed by what he called canalization of developmental pathways; he supposed that the organism's genetics evolved to ensure that development proceeded in a certain way regardless of normal environmental variations.

<i>Dawkins vs. Gould</i> Book by Kim Sterelny

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The extended evolutionary synthesis consists of a set of theoretical concepts argued to be more comprehensive than the earlier modern synthesis of evolutionary biology that took place between 1918 and 1942. The extended evolutionary synthesis was called for in the 1950s by C. H. Waddington, argued for on the basis of punctuated equilibrium by Stephen Jay Gould and Niles Eldredge in the 1980s, and was reconceptualized in 2007 by Massimo Pigliucci and Gerd B. Müller. Notably, Dr. Müller concluded from this research that Natural Selection has no way of explaining speciation, saying: “selection has no innovative capacity...the generative and the ordering aspects of morphological evolution are thus absent from evolutionary theory.”

This glossary of genetics and evolutionary biology is a list of definitions of terms and concepts used in the study of genetics and evolutionary biology, as well as sub-disciplines and related fields, with an emphasis on classical genetics, quantitative genetics, population biology, phylogenetics, speciation, and systematics. Overlapping and related terms can be found in Glossary of cellular and molecular biology, Glossary of ecology, and Glossary of biology.

In evolutionary biology, developmental bias refers to the production against or towards certain ontogenetic trajectories which ultimately influence the direction and outcome of evolutionary change by affecting the rates, magnitudes, directions and limits of trait evolution. Historically, the term was synonymous with developmental constraint, however, the latter has been more recently interpreted as referring solely to the negative role of development in evolution.

References

  1. 1 2 3 Dawkins, R. (1976). The Selfish Gene. Oxford University Press, Oxford, UK. ISBN   978-0-19-286092-7.
  2. 1 2 Haig, David (July 1, 2012). "The strategic gene". Biology & Philosophy. 27 (4): 461–479. doi:10.1007/s10539-012-9315-5. ISSN   0169-3867. S2CID   28597902.
  3. Gardner, Andy (2016). "The Strategic Revolution". Cell. 166 (6): 1345–1348. doi: 10.1016/j.cell.2016.08.033 . hdl: 10023/11635 . PMID   27610556. S2CID   34023979.
  4. Dawkins, Richard (January 1979). "Twelve Misunderstandings of Kin Selection". Zeitschrift für Tierpsychologie. 51 (2): 184–200. doi:10.1111/j.1439-0310.1979.tb00682.x.
  5. Ågren, J. Arvid (December 1, 2016). "Selfish genetic elements and the gene's-eye view of evolution". Current Zoology. 62 (6): 659–665. doi:10.1093/cz/zow102. ISSN   1674-5507. PMC   5804262 . PMID   29491953.
  6. Tiège, Alexis De; Tanghe, Koen B.; Braeckman, Johan; Peer, Yves Van de (2015). Life's dual nature: a way out of the impasse of the gene-centred 'versus' complex systems controversy on life. pp. 35–52. doi:10.1007/978-3-319-19932-0_3. ISBN   9783319199313. S2CID   82619358.{{cite book}}: |work= ignored (help)
  7. Crow, James F. (February 15, 2001). "The beanbag lives on". Nature. 409 (6822): 771. Bibcode:2001Natur.409..771C. doi:10.1038/35057409. PMID   11236977. S2CID   205014199.
  8. Maynard Smith, J. (1998). Evolutionary Genetics (2nd ed.). Oxford University Press, Oxford, UK. p. 10.
  9. Fisher, R. A. (1930). The Genetical Theory of Natural Selection. Oxford University Press, Oxford, UK. ISBN   978-0-19-850440-5.
  10. Okasha, Samir (2016). "Population Genetics". In Zalta, Edward N. (ed.). The Stanford Encyclopedia of Philosophy (Winter 2016 ed.). Metaphysics Research Lab, Stanford University. Retrieved September 26, 2018.
  11. 1 2 3 Dawkins, R. (1982). The Extended Phenotype. Oxford University Press, Oxford, UK. ISBN   978-0-19-288051-2.
  12. Hamilton, W. D. (1963). "The evolution of altruistic behavior". The American Naturalist. 97 (896): 354–356. doi:10.1086/497114. S2CID   84216415.
  13. Hamilton, W. D. (1964). "The genetical evolution of social behaviour I". Journal of Theoretical Biology. 7 (1): 1–16. Bibcode:1964JThBi...7....1H. doi:10.1016/0022-5193(64)90038-4. PMID   5875341. S2CID   5310280.
  14. Hamilton, W. D. (1964). "The genetical evolution of social behaviour II". Journal of Theoretical Biology. 7 (1): 17–52. Bibcode:1964JThBi...7...17H. doi:10.1016/0022-5193(64)90039-6. PMID   5875340.
  15. Pittendrigh, C. S. (1958). "Adaptation, natural selection and behavior" . In Roe, A.; Simpson, G. G. (eds.). Behavior and evolution. Yale University Press, USA.
  16. 1 2 3 Williams, G. C. (1966). Adaptation and Natural Selection . Princeton University Press, USA.
  17. Williams, George C. (1995). "A package of information". Edge.org.
  18. Gogarten, J. Peter; Doolittle, W. Ford; Lawrence, Jeffrey G. (December 1, 2000). "Prokaryotic Evolution in Light of Gene Transfer". Molecular Biology and Evolution. 19 (12): 2226–2238. doi: 10.1093/oxfordjournals.molbev.a004046 . ISSN   0737-4038. PMID   12446813.
  19. Thomas, Christopher M.; Nielsen, Kaare M. (September 2005). "Mechanisms of, and Barriers to, Horizontal Gene Transfer between Bacteria". Nature Reviews Microbiology. 3 (9): 711–721. doi:10.1038/nrmicro1234. ISSN   1740-1534. PMID   16138099. S2CID   1231127.
  20. 1 2 Williams, G. C. (1992). Natural Selection: Domains, Levels and Challenges. Oxford University Press, Oxford, UK. ISBN   978-0-19-506932-7.
  21. Dawkins, Richard (1995). River out of eden : a Darwinian view of life. New York, NY. ISBN   0-465-01606-5.{{cite book}}: CS1 maint: location missing publisher (link)
  22. Dawkins, Richard (2016). The selfish gene (40th anniversary ed.). Oxford, United Kingdom. pp. 10–13. ISBN   978-0-19-109307-4.{{cite book}}: CS1 maint: location missing publisher (link)
  23. 1 2 Haig, D. (1997). "The Social Gene". In Krebs, J. R.; Davies, N. B. (eds.). Behavioural Ecology . Blackwell Scientific, UK. pp.  284–304. ISBN   9780865427310.
  24. 1 2 Cronin, H. (1991). The Ant and the Peacock. Cambridge University Press, Cambridge, UK. ISBN   978-0-521-32937-8.
  25. Williams, G. C. (1985). "A defense of reductionism in evolutionary biology". Oxford Surveys in Evolutionary Biology. 2: 1–27.
  26. Clark, Ronald W. (1968). JBS: The Life and Work of J. B. S. Haldane. Hodder & Stoughton. ISBN   978-0-340-04444-5.
  27. Hamilton WD (July 1964). "The genetical evolution of social behaviour. I". Journal of Theoretical Biology. 7 (1): 1–16. Bibcode:1964JThBi...7....1H. doi:10.1016/0022-5193(64)90038-4. PMID   5875341. S2CID   5310280.
  28. Krieger, Michael J. B.; Ross, Kenneth G. (January 11, 2002). "Identification of a Major Gene Regulating Complex Social Behavior". Science. 295 (5553): 328–332. Bibcode:2002Sci...295..328K. doi: 10.1126/science.1065247 . ISSN   0036-8075. PMID   11711637. S2CID   12723736.
  29. Krieger, Michael J. B.; Ross, Kenneth G. (October 1, 2005). "Molecular Evolutionary Analyses of the Odorant-Binding Protein Gene Gp-9 in Fire Ants and Other Solenopsis Species". Molecular Biology and Evolution. 22 (10): 2090–2103. doi: 10.1093/molbev/msi203 . ISSN   0737-4038. PMID   15987877.
  30. Queller, David C.; Ponte, Eleonora; Bozzaro, Salvatore; Strassmann, Joan E. (January 3, 2003). "Single-Gene Greenbeard Effects in the Social Amoeba Dictyostelium discoideum". Science. 299 (5603): 105–106. Bibcode:2003Sci...299..105Q. doi:10.1126/science.1077742. ISSN   0036-8075. PMID   12511650. S2CID   30039249.
  31. Smukalla, Scott; Caldara, Marina; Pochet, Nathalie; Beauvais, Anne; Guadagnini, Stephanie; Yan, Chen; Vinces, Marcelo D.; Jansen, An; Prevost, Marie Christine (2008). "FLO1 Is a Variable Green Beard Gene that Drives Biofilm-like Cooperation in Budding Yeast". Cell. 135 (4): 726–737. doi:10.1016/j.cell.2008.09.037. PMC   2703716 . PMID   19013280.
  32. Leigh, Egbert Giles (1971). Adaptation and Diversity. Cooper, San Francisco, USA.
  33. 1 2 Shelton, Deborah E.; Michod, Richard E. (April 3, 2009). "Philosophical foundations for the hierarchy of life". Biology & Philosophy. 25 (3): 391–403. doi:10.1007/s10539-009-9160-3. S2CID   15695083.
  34. Gould, Stephen Jay (June 12, 1997). "Darwinian Fundamentalism". The New York Review of Books. Retrieved March 12, 2014.
  35. "Ernst Mayr: What evolution is". Edge Magazine. October 31, 2001. Retrieved July 21, 2010.
  36. 1 2 Gould, S. J. (1990). "Caring Groups and Selfish Genes". The Panda's Thumb: More Reflections in Natural History. Penguin Books, London, UK. pp. 72–78.
  37. Sterelny, K. (2007). Dawkins vs. Gould: Survival of the Fittest. Icon Books, Cambridge, UK.
  38. Eldredge, N. (2004). Why We Do It: Rethinking Sex and The Selfish Gene . W. W. Norton, New York, USA. ISBN   9780393050820.
  39. Eldredge (2004), p. 233

Sources