New genetic analyses of wild baboons in southern Kenya reveals that most of them carry traces of hybridization in their DNA. As a result of interbreeding, about a third of their genetic makeup consists of genes from another, closely-related species. The researchers led by Jenny Tung from Duke University and now at the Max Planck Institute for Evolutionary Anthropology, measured genetic variation and gene activity to understand the possible costs and benefits of genetic mixing in primates, including humans.