When the mothers tried to wean them, they would sometimes throw tantrums and scream and run around. "It was fun to observe the juveniles twirling around in the trees, chasing one another and trying to pull each other down. "Bonobos are well-known for being playful, even as adults," Kovalaskas says. Wild bonobos, an endangered species, are only found in forests south of the Congo River in the DRC. Before joining Emory she spent nine months in the field, studying the social development of juvenile bonobos in the Democratic Republic of Congo (DRC).
Sarah Kovalaskas, an Emory graduate student of anthropology, is first author of the paper. "Understanding the physiological mechanisms underlying the differences in chimpanzee and bonobo behaviors - particularly the much stronger propensity of bonobos toward conflict resolution instead of fighting - may also give us information about the genes underlying our own behaviors," Lindo says. The two species also share around 99 percent of human DNA, making them our closest living relatives in the animal kingdom. "Chimpanzees and bonobos are fascinating because they are very, very closely linked genetically but they have huge behavioral differences," he says. Lindo is a geneticist specialized in ancient DNA and natural selection.
"We contrasted the genomes of both species to understand how natural selection has shaped differences between the two closely related primates." "Our paper is the first whole-genome positive selection scan between chimpanzees and bonobos," says John Lindo, Emory assistant professor of anthropology and senior author of the study. The journal Genes, Brain and Behavior published the comparative analysis, conducted by anthropologists at Emory University.