A new genetic analysis of chimpanzees and bonobos reveals that these two great ape species likely interbred several hundred thousand years ago. The results , published in the 28 October issue of Science, will provide a better understanding of the genetic flow that plays a role in the evolution of great apes.
Tomas Marques-Bonet of the Universitat Pompeu Fabra noted that studying gene flow between ancient humans such as Neanderthals, Denisovans and the ancestors of modern humans has revealed numerous genes under selection that affect disease and an individual's traits. Great apes, or hominids, are a group of species that includes gorillas, humans, chimpanzees and bonobos, among others. Of this group, chimpanzees and bonobos are the closest living relatives to modern humans.
While these two species are known to interbreed in captivity, historic genetic flow between the two species in the wild is less clear. To gain more insights, Marques-Bonet and colleagues analyzed the complete genomes of 10 bonobos and 65 chimpanzees. They included more chimpanzees from various regions in Africa in their analysis, because previous genetic studies have suggested that four distinct geographical subspecies of chimpanzee exist.
Based on their analyses, they estimate that gene flow between the two species occurred between , and , years ago. Central, eastern and Nigeria-Cameroon chimpanzees share significantly more genetic information with bonobos than western chimpanzees.
What's more, similar to Neanderthal genetic patterns in humans, some bonobo genetic information has been deleted in the chimpanzee genome, suggesting that some bonobo genes may have been disadvantageous for chimpanzees.
