1Cooperation and Competition between Relatives Supplementary Online Information

Here, we expand upon three areas briefly mentioned in the main text. Specifically, we describe: (A) an extreme empirical example of when competition between relatives is so severe that it negates and kin selection for altruism towards relatives – competition for mates between male fig wasps; (B) how the rash generalisations given in the main text may help us explain when kin selection theory hasn’t been successful in explaining empirical patterns; (C) how the large body of research on sex allocation (allocation of resources to male and female reproduction) in structured populations relates to the topics discussed in the main text. Fighting In Fig Wasps One useful system for the empirical study of kin selection when relatives compete is the level of fighting between male fig wasps (1). Fig wasps develop within the fruit of fig trees, and include mutualistic pollinating species as well as parasitic non-pollinating species. In many species the males are wingless, and mate with the winged females before the females disperse from the fruit. At one extreme, males of some non-pollinating species are highly modified for combat with armoured bodies and huge mandibles. Thes