PT  - JOURNAL ARTICLE
AU  - Jeremy Van Cleve
AU  - Erol Akçay
TI  - Pathways to social evolution: reciprocity, relatedness, and synergy
AID  - 10.1101/000521
DP  - 2013 Jan 01
TA  - bioRxiv
PG  - 000521
4099  - http://biorxiv.org/content/early/2013/11/16/000521.short
4100  - http://biorxiv.org/content/early/2013/11/16/000521.full
AB  - Many organisms live in populations structured by space and by class, exhibit plastic responses to their social partners, and are subject to non-additive ecological and fitness effects. Social evolution theory has long recognized that all of these factors can lead to different selection pressures but has only recently has attempted to synthesize how these factors interact. Using models for both discrete and continuous phenotypes, we show that analyzing these factors in a consistent framework reveals that they interact with one another in ways not previously emphasized. Specifically, behavioral responses (reciprocity), genetic assortment (relatedness), and synergy interact in non-trivial ways that cannot be easily captured by simple summary indices. We demonstrate the importance of these interactions by showing how they have been neglected in previous synthetic models of social behavior both within and between species. These interactions also affect the level of behavioral responses that can evolve in the long run; proximate biological mechanisms are evolutionarily stable when they generate enough responsiveness relative to the level of responsiveness that exactly balances the ecological costs and benefits. Given the richness of social behavior across taxa, these interactions should be a boon for empirical research as they are likely crucial for describing the complex relationship between ecology, demography, and social behavior.