> [!infobox] <s class="aside-in"><em>mentioned in 5 topics, 12 evergreens, 2 sources</em></s> #### <s class="topic-title">[[group selection]]</s> Group selection takes place when a trait is passed on because the trait that an individual or individuals carry may be detrimental to themselves, but benefits the survival of the group. **See**:: [[natural selection]], [[inclusive fitness]], [[Evolution]] #### Application In order to see what evolves via group selection (or where group selection is the most powerful force of selection) you need to apply three rules. 1. Identify the relevant groups 2. Compare fitness of individuals within groups 3. Compare fitness of groups in the total population In [[10_Sources/books - Darwin's Cathedral|Darwin's Cathedral]], [[David Sloan Wilson]] outlines two caveats for group selection to apply to any trait. The first of these is that not every group is an adaptive unit; If there is not competition between groups, there is not a driving force for [[group selection]] to take advantage of. The second is that groups must be defined for any given trait relative to the context that trait is meaningful in. He claims that every other theory of group selection (one's that rely on [[kin selection]] or [[game theory]]) can be explained using [[group selection]] if you follow these rules. ^e8dce2 Whatever group has the higher average fitness wins (caveats apply). ##### The averaging fallacy One of the reasons that group selection went out of style for a time was that for some traits if you put individuals against each other the one without the trait will win, but if you average fitness over the whole population, the individuals with traits win. You could say that this follows the rules of [[individual selection]], because the trait is on average adaptive for the individual, but by doing this you have simply ignored the fact that it is only adaptive because that individual is part of a group, effectively defining group selection out of existence. #### Influence [[Group selection]] is can be a very powerful force through it's reinforcement of [[reciprocal altruism]]. When group develops strong levels of cooperation while they are separated from the wider group ^[much as [[homo sapiens]] was separated from [[Homo erectus]] and [[Homo neanderthalis]] in eastern [[Africa]] 150,000 years ago: [[Greater cooperation and communication has lead to the success of humans as a species]]] it allows them to out compete that group when they are recombined. In the same species this leads the [[founder effect]] and in separate species in leads to extinction. ^[[[lecture - Behavioral Evolution#^igzkks]]] Group selection can be a weak force in genetic [[evolution]], but is often the strongest force when it comes to [[Cultural Evolution]]. This makes discussions around group selection veer much more towards [[Psychology]] than [[Biology]], but [[Biology]] very much has a part to play in discussions of [[group selection]] and [[Cultural Evolution]]. #### History The history of group selection is an interesting one, but our modern conception reflects ideas that have been around since the hypothesis of [[natural selection]]. > There can be no doubt that a tribe including many members who, from possessing in a high degree the spirit of patriotism, fidelity, obedience, courage, and sympathy, were always ready to aid one another, and to sacrifice themselves for the common good would be victorious over most other tribes; and this would be [[natural selection]]. > ^[[[10_Sources/books - Darwin's Cathedral#288296631q]]] > > <cite> [[Charles Darwin]] 1871 </cite> While group selection and [[Cultural Evolution]] were more than within the Darwin's understanding of [[natural selection]], later developments would turn people off of group selection for most of the 20th century. > [!wikipedia] [group selection](https://en.wikipedia.org/wiki/Group%20selection) > > 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. In the 1930s, R.A. Fisher and J.B.S. Haldane proposed the concept of [[kin selection]], a form of altruism from the gene-centered view of evolution, arguing that animals should sacrifice for their relatives, and thereby implying that they should not sacrifice for non-relatives. 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 individual. They argued on the basis of mathematical models that individuals would not altruistically sacrifice fitness for the sake of a group. A consensus emerged that group selection did not occur. In 1994 [[David Sloan Wilson]] and [[Elliott Sober]] argued for multi-level selection, including group selection, on the grounds that groups, like individuals, could compete. In 2010 three authors including E. O. Wilson, known for his work on social insects especially ants, again revisited the arguments for group selection. They argued that group selection can occur when competition between two or more groups, some containing altruistic individuals who act cooperatively together, is more important for survival than competition between individuals within each group, provoking a strong rebuttal from a large group of ethologists. #### Related - [[Farming outcompeted foraging by allowing for higher populations]] - [[Group selection solves the fundamental problem of social life]] - [[Highly integrated social control allows groups to act as adaptive units]] - [[How can something be adaptive and net bad]] - [[Individual selection is an emergent mechanic of group selection]] - [[Social control promotes highly altruistic behavior within groups]] - [[What is the link between evolution and social behavior]]