Research description: My research is on the genetics and evolution of complex traits. I am especially interested in morphological diversification in primates. In this area I have focused on New World Monkeys and on the baboon clade (Papionins) where in collaboration with Gabriel Marroig and Becky Ackermann we have generated the methods required to use the structure of heritable variation to test whether diversification among members of a clade, both modern and fossil, are consistent with evolution by genetic drift and reconstruct the selection pressures necessary to produce observed differences among species. We have performed quantitative genetic analyses of cranial morphology in rhesus macaques, baboons, and in two species of tamarins. In addition we work on the genetics of complex traits and diseases in mouse models. In addition to clinical relevance, these studies have led to the analysis of QTL effects and epistasis. We've developed models for the evolution of gene effects and found empirically that gene effects can vary dramatically with environment and with genotypes at other loci.