Social selection
The behavioral aspect is concerned with cooperative game theory and the formation of social groups to maximize the production of offspring.
[4][5] Other researchers, such as biologist Mary Jane West-Eberhard and evolutionary medicine researcher Randolph M. Nesse, instead view sexual selection as a subcategory of social selection,[list 1] with Nesse and anthropologist Christopher Boehm arguing further that altruism in humans held fitness advantages that enabled evolutionarily extraordinary cooperativeness and the human capability of creating culture, as well as desertion, abandonment, banishment, and capital punishment by band societies against bullies, thieves, free-riders, and psychopaths.
[list 2] Short for the genetic-portfolio balancing hypothesis, this idea, proposed by Roughgarden, is used as an alternative to the Red Queen and Mueller's ratchet hypotheses to explain the existence of sexual reproduction within the framework of social selection.
From this theory, Roughgarden concludes that the main benefit of sexual reproduction is the maintenance of genetic diversity when compared to similar asexual populations.
By considering the evolution of anisogamy in hermaphroditic marine invertebrates and bisexual plants, the theory postulates of a gene locus which controls both sperm and egg size produced by an organism.
[1] Males arising in primarily hermaphroditic species gain an advantage in certain environments as fertilizers because they lack the energy cost of producing eggs.
[1] Simultaneous hermaphrodism exists in species with pre-Cambrian roots, and several families of organisms have shifted between hermaprodism and gonochoism over their evolutionary history.
[1] Mating can therefore serve purposes beyond reproduction, if the maintenance of social structures does not decrease effective fitness.
Several asexual species of whiptail lizards have been observed to engage in mating and pair-bonding despite the lack of gametic fusion.
[20] Animal behavior can be understood as the intersection of three primary elements: genetic foundations, social systems, and individual reaction.
[9] Citing cross-cultural research conducted by social psychologist David Buss,[23][24] psychologist Geoffrey Miller has argued that if humans prefer altruistic mating partners that would select by mate choice for altruism directly,[25] while evolutionary medicine researcher Randolph M. Nesse has argued that humans with altruistic tendencies receive fitness advantages because they are preferred as social partners,[14] and this enabled humans as a species of becoming extraordinarily cooperative and capable of creating culture.
