Phylogenetic history of social evolution and habitat use in the Aphelocoma jays

Abstract

Historical changes in social systems and habitat use of the jays of the genus Aphelocoma were evaluated using parsimony analysis based on an independent phylogenetic estimate. Social evolution has been phylogenetically conservative in this genus, with the origin of cooperative breeding predating the diversification of the genus, and reduction in cooperation occurring subsequently in two independent lineages. Invasion of new habitat types has been less phylogenetically conservative in the genus at the level of analysis in the present study. Although changes in the social system and habitat use appear to be correlated across phylogenetic history, statistical significance of the correlation is difficult to assess. Although these results suggest that comparative studies of social evolution in the New World jays may be biased by non-independence of examples, a potential solution to this problem may lie in analysis of independent evolutionary derivations.