sign in sign up
<<
Home , Altruism (biology), David Sloan Wilson, Group selection, Kin selection, Richard Dawkins, The Selfish Gene

;;;;;;;;;;;;;;;;;;;;;;

English 100 Essay Dawkins and others in the 1960s is the predominant view among modern evolutionary biologists. The Understanding main premise relies on the concept of the ÒgeneÓ as being the ultimate, fundamental unit of natural : selection. By the basic principles of , that are more successful at replicating Selection vs. Group themselves will, by default, become more numerous in the population. Therefore, a gene that happens Selection to increase the general Þtness of the individual in Michaela Lewis which it is located will be more likely to be passed down to the next generation. This understanding leads us to the concept of the ÒselÞsh gene,Ó where Almost everybody feels that they understand natural selection applies at the level of individual DarwinÕs Theory of Evolution by natural selection. genetic codes; genes which make the behave It is as simple as Òsurvival of the Þttest.Ó There is, in ways that ÒselÞshlyÓ increase the chances of the though, an important subtlety that is often omitted by immortal geneÕs survival will become more frequent the textbooks, providing a radical shift in the in any given population. The which way we view evolution and natural selection. In the carry thousands of these genes can then be viewed early twentieth century, theorists uncritically assumed as ÒvehiclesÓ of selection, since they constitute a that Darwinian selection could apply and produce coordinated, fairly uniÞed collection of genes. Genes adaptations at many levels of the biological , must work together in organizing the survival and from individuals to populations to ecosystems. In of the host vehicle, because they are all the 1960s and , a scientiÞc shift occurred and locked in the same Òboat.Ó For example, a gene for evolutionary biologists began viewing genes as the powerful jaws and hunting skills would not help the fundamental . Noted evolutionary organism survive if all the other genes were coded theorist wrote the revolutionary, for the body of an herbivore; the organism would and now classic, book The SelÞsh Gene in 1976, be less likely to survive and reproduce, thereby explaining the new genetic view and making it more stopping the genetic line and reducing the frequency accessible to lay-people and scientists alike. ÒNaiveÓ of that particular carnivorous gene in the population group selectionism Ð such as the belief that any (Dawkins, 1976). Although natural selection actually and all individuals would unconditionally sacriÞce operates at the level of selÞsh genes, the general themselves for the survival of the Ð was Þtness of individuals often corresponds with that of expelled from the accepted scientiÞc understanding the genes. This makes it appear as though selection of natural selection, and held up as an example of applies at the individual level, and for the sake of how not to . Only in recent years has a newer convenience, biologists often refer to Þtness levels version of the theory come back into of organisms determining the selection process. It is the arena of debate, arguing that populations should always important, though, to be able to return to what be viewed as vehicles of selection in the same way Dawkins calls the ÒgeneÕs eye viewÓ of evolutionary that individual organisms are. This new perspective change - justifying organismÕs behavior on the basis of is mainly supported by the writings of E.O. Wilson gene preservation (Dawkins, 1976). and , two respected American Groups or populations can also be viewed evolutionary biologists. The controversy between as vehicles of replicators, but far weaker, and less purist gene selectionism and the Multilevel Selection distinct, than individual physical colonies of genes or Theory (MST) may seem theoretical, but the reasoning cells. In this sense, then, a sort of Ògroup selectionÓ behind the two perspectives profoundly changes could in theory be possible, but it seems unlikely the way scientists understand evolutionary changes, that group-level adaptations between populations kin , and group behavior. The claim now would occur. Lower-level selection likely overrides becomes a question: Òsurvival of the Þttest what? most of the inßuences from higher-level selection, so Gene? Organism? Or group?Ó the relevance of any possible group adaptations is The gene selectionist perspective proposed by debatable. Genes are still central as the only units of 114 replicator selection (Cronin, 1991; Dawkins, 1976). relatively stable ESS. It is possible for to The controversy regarding group selection enter into conscious pacts which, in the long term, has its roots in the question of demonstrated improve the survival and reproduction beneÞts of altruism: why do individuals sacriÞce themselves every member of the group, but in general terms or their time and energy in order to help other of animal strategies, ESSs will evolve that give an organisms? In the early days of group selectionism, average beneÞt to all members and that penalize any this sort of behavior was thought to have evolved deviance from the norm. Òfor the good of the speciesÓ or Òfor the good of the The second and opposing point of view in this group.Ó The most common form of altruistic self- controversy is the new version of group selection, also sacriÞce is reproduction and the care of offspring. known as Multilevel Selection Theory. Evolutionary Altruistic behaviors are also common between theorists who support the view that selection can close members. This altruism results in operate on higher biological levels include E. O. the increased Þtness, survival, and likelihood of Wilson, V. C. Wynne-Edwards, David Sloan Wilson, reproduction of non-descendant relatives, also called and . These renowned scientists do . As Dawkins explains in his 1976 book not renounce the gene as a basic unit of selection, The SelÞsh Gene and in a 2008 journal article entitled but instead argue that since individuals can be ÒThe Evolution of Altruism: What Matters in Gene regarded as populations of coordinated, cooperating Selection,Ó kin selection is still indirectly driven by genes, groups Ð as long as there is some degree of selÞsh gene behavior. Individuals are programmed coordination and harmony in their parts Ð should by their genes to help close kin survive and reproduce also be viewed as distinct ÒorganismsÓ that can act because, by doing so, they help perpetuate copies of as vehicles of natural selection (Wilson & Wilson, their genes Ð since offspring and relatives share up 2007). Proponents of this perspective contend that to 50% of the altruistic individualÕs genetic material. these vehicles of selection are the important factors This explanation of kin selection provides a very around which the entire view of selection must be acceptable model of the evolution of cooperative restructured. behavior. Sociobiologist W. D. Hamilton delineated In the new perspective of Multilevel the mathematical model of kin selection, calculating Selection theory, it is vital to differentiate between the probability that two individuals, either directly the environmental pressures and descendent or with common ancestry, will share within a group versus the between genetic material (Hamilton, 1964). separate groups or populations. David Sloan Wilson Patterns of group behavior can be predicted accepts that within-group selection follows the within the selÞsh replicator theory by the use of basic principles of individual, selÞsh competition John Maynard SmithÕs concept of Evolutionarily (McAndrew, 2002). In a 1997 journal article, Wilson Stable Strategies (ESS); Dawkins describes this argues that group-level adaptations do not evolve important as Òa strategy which, if most members into adaptive units for all traits, but instead only for of a population adopt it, cannot be bettered by an certain traits which increase the evolutionary ÒÞtnessÓ alternative strategyÓ (Dawkins, 1967). This means of each group in relation to other populations that the most effective survival plan for an individual, (McAndrew, 2002). He states that although the and the genes which inhabit it, depends upon what occurrence of individual altruism may appear to the majority of the population is doing. For example, reduce the Þtness of the organism, Òit may sometimes if all the members of a group of are altruistic, become adaptive because groups of altruists will be the best reproductive strategy for one individual more Þt than groups of non-altruists under the right might be to act selÞshly. Since these ÒselÞshÓ conditionsÓ (McAndrew, 2002). individuals are more successful reproductively, Some of the main evidence for group the population will eventually become almost selectionism theories is based upon entomological entirely ÒselÞsh,Ó at which point, there might be a studies. E. O. Wilson, in particular, has done a large reproductive payoff to acting altruistically. As the amount of research in the Þeld of Myrmecology, group dynamics oscillate back and forth between the study of , a branch of entomology. For these two extremes, the most effective strategy for ants, group selection theories appear very useful each individual will converge on some average, for explaining their behaviors and physiology. evolutionarily stable, strategy. Following any colonies can be, and sometimes are, viewed as super- environmental change, there may be a period of organisms, owing to the specialization of duties and evolutionary instability during which frequencies extreme altruism of worker ants (Wilson and Elliott, of survival strategies ßuctuates until it reaches a 1994). Gene selectionists think that this may be due

115 in part to the fact that more than 50% of the kin antsÕ selection perspective, since selection occurs between genetic material is shared (Dawkins, 1976). Group populations in a species and between species, who is selectionists maintain that eusocial insect relations, to decide at what level the group adaptations become such as ants and honeybees, illustrate a classic unimportant? ÒShould we not then expect to example of group-level vehicles of gene survival. refrain from killing antelopes, Ôfor the good of the Multilevel selectionists distance themselves ?ÕÓ Dawkins questions, partly tongue-in- from the naivety of the uninformed 19th century group cheek: ÒBut then, what of the need to perpetuate the selectionism theories. Instead, they focus on the whole phylum of vertebrates?Ó (Dawkins, 1976). importance of the group or population as an organism Within the DarwinÕs Theory of Evolution, and as a vehicle of natural selection. Applying the speciÞc perspectives such as these are still being theory of MLS to social interaction, Wilson debated, and as scientists collect more empirical concludes that religious ideals and ethical norms research data about the actual behaviors of genes, may provide mechanisms which contribute to organisms, kin groups, and populations, it will be the coordination of group function. , too, possible to reÞne our understanding of the different may represent a group-level adaptation that helps processes of selection in . The comparison of populations of humans adapt to environmental purist gene selection and the new Multilevel Selection changes (OÕGorman, Sheldon, Wilson, 2008). Theory is, to some extent, a debate of semantics. The controversy surrounding the gene Whether we should view individuals and groups selectionist and group selectionist perspectives is a as vehicles of selection seems like an unimportant complex and signiÞcant debate. There are important distinction, but it profoundly inßuences the context in consequences of accepting either view, and criticisms which we view situations of group dynamics. Despite of both theories that must be considered. For the propaganda put out by proponents of Intelligent example, both David Wilson and E. O. Wilson criticize Design and , the acceptance of the actual the selÞsh replicator theory for considering individual validity of the general theory of evolution is almost organisms, colonies of coordinated parts, as vehicles unanimous among scientists. Debates about speciÞc of natural selection which can be more or less ÒÞtÓ in perspectives within the Darwinian Òsurvival of the their environments and not following the deÞnition ÞttestÓ model are actually useful and encouraged to the same conclusion for groups. On the other within . The academic openness of the hand, Dawkins proposes the question of how group scientiÞc method helps scientists in the continuing selectionists are to decide which level is the important pursuit of a true understanding of the evolution of one for group adaptations. Following the multilevel individuals and groups.

Cronin, H. (1991). The Ant and the Peacock: Altruism and from Darwin to Today. Cambridge: Cambridge University Press. Dawkins, R. (2008). The Evolution of Altruism - What Matters is Gene Selection. New Scientist. 197(2638). 17. Retrieved April 14, 2008 from Academic Search Premier database. Dawkins, R. (1976). The SelÞsh Gene. : . McAndrews, F. (2002). New Evolutionary Perspectives on Altruism: Multilevel-Selection and Costly-Signaling Theories. Retrieved April 27, 2008, from the Department of Psychology, Knox College. Website: http://faculty.knox.edu/fmcandre/CDIR1129.pdf OÕGorman, R., Sheldon, K. M., Wilson, D.S. (2008). For the Good of the Group? Exploring Group-Level Evolutionary Adaptations Using Multilevel Selection Theory. Group Dynamics, Research, Theory and Practice. 12(1). 17-26. Retrieved April 14, 2008 from Academic Search Premier database. Sober, E., Wilson, D.E. (2008). Re-Introducing Group Selection to the Human Behavioral . Behavioral and Sciences. 17(4). 585-654. Williams, G.C. (1966). Adaptation and Natural Selection. Princeton: Princeton University Press. Wilson, E.O., Wilson, D.S. (2007). Evolution: Survival of the Selßess. New Scientist. 2628.

116