Group selection

Early authors such as V. C. Wynne-Edwards and Konrad Lorenz argued that the behavior of animals could affect their survival and reproduction as groups, speaking for instance of actions for the good of the species.

From the mid-1960s, evolutionary biologists such as John Maynard Smith, W. D. Hamilton, George C. Williams, and Richard Dawkins argued that natural selection acted primarily at the level of the gene.

In 2010 three authors including E. O. Wilson, known for his work on social insects especially ants, again revisited the arguments for group selection.

"[4][5] Once Darwinism had been accepted in the modern synthesis of the mid-twentieth century, animal behavior was glibly explained with unsubstantiated hypotheses about survival value, which was largely taken for granted.

The naturalist Konrad Lorenz had argued loosely in books like On Aggression (1966) that animal behavior patterns were "for the good of the species",[1][6] without actually studying survival value in the field.

[6] Richard Dawkins noted that Lorenz was a "'good of the species' man"[7] so accustomed to group selection thinking that he did not realize his views "contravened orthodox Darwinian theory".

[13][14] It was at that time generally agreed that this was the case even for eusocial insects such as honeybees, which encourages kin selection, since workers are closely related.

Kin selection theory treats the narrower but simpler case of the benefits to close genetic relatives (or what biologists call 'kin') who may also carry and propagate the trait.

[27] In 1994, David Sloan Wilson and Elliott Sober argued that the case against group selection had been overstated.

Wilson wrote, "At all scales, there must be mechanisms that coordinate the right kinds of action and prevent disruptive forms of self-serving behavior at lower levels of social organization.

[31] An experiment by William Muir compared egg productivity in hens, showing that a hyper-aggressive strain had been produced through individual selection, leading to many fatal attacks after only six generations; by implication, it could be argued that group selection must have been acting to prevent this in real life.

[33] Group selection has most often been postulated in humans and, notably, eusocial Hymenoptera that make cooperation a driving force of their adaptations over time and have a unique system of inheritance involving haplodiploidy that allows the colony to function as an individual while only the queen reproduces.

In a 2005 article,[35] E. O. Wilson argued that kin selection could no longer be thought of as underlying the evolution of extreme sociality, for two reasons.

First, he suggested, the argument that haplodiploid inheritance (as in the Hymenoptera) creates a strong selection pressure towards nonreproductive castes is mathematically flawed.

[36] Second, eusociality no longer seems to be confined to the hymenopterans; increasing numbers of highly social taxa have been found in the years since Wilson's foundational text Sociobiology: A New Synthesis was published in 1975.

[40] Spatial populations of predators and prey show restraint of reproduction at equilibrium, both individually and through social communication, as originally proposed by Wynne-Edwards.

[44] Social behaviors such as altruism and group relationships can impact many aspects of population dynamics, such as intraspecific competition and interspecific interactions.

[4] This supports the idea of multilevel selection, but kinship also plays an integral role because many subpopulations are composed of closely related individuals.

[46] The evolution of this trait benefits the group by providing protection, but could be disadvantageous to the individual if the howling draws the predator's attention to them.

By affecting these interspecific interactions, multilevel and kinship selection can change the population dynamics of an ecosystem.

[46] Multilevel selection attempts to explain the evolution of altruistic behavior in terms of quantitative genetics.

[50] Gene-culture coevolution allows humans to develop highly distinct adaptations to the local pressures and environments more quickly than with genetic evolution alone.

Boyd and Richerson believe that the ability to collaborate evolved during the Middle Pleistocene, a million years ago, in response to a rapidly changing climate.

[53] In 2015, William Yaworsky and colleagues surveyed the opinions of anthropologists on group selection, finding that these varied with the gender and politics of the social scientists concerned.

[55][56][57][58] The vast majority of behavioural biologists have not been convinced by renewed attempts to revisit group selection as a plausible mechanism of evolution.

[59] The use of the Price equation to support group selection was challenged by van Veelen in 2012, arguing that it is based on invalid mathematical assumptions.

[60] Advocates of the gene-centered view of evolution such as Dawkins and Daniel Dennett remain unconvinced about group selection.

[65] The evolutionary biologist Jerry Coyne summarizes the arguments in The New York Review of Books in non-technical terms as follows:[64] Group selection isn't widely accepted by evolutionists for several reasons.

First, it's not an efficient way to select for traits, like altruistic behavior, that are supposed to be detrimental to the individual but good for the group.

Finally, other, more plausible evolutionary forces, like direct selection on individuals for reciprocal support, could have made humans prosocial.