In a development which could lead to a better understanding of human evolution, scientists have unlocked the genetic map of the bonobo, a great and mild-mannered species of African ape. Chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) share almost 99 percent of human DNA. The scientists who recently mapped the bonobo genome found that, in 3 percent of that shared genetic material, humans are more closely related to both bonobos and chimpanzees than the two apes are to each other.
“Bonobos and chimpanzees are our closest living relatives and that is something that you can clearly see in the genome,” said Kay Prüfer, with the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, who was one of the researchers. “I think the most interesting thing that I saw in the genome is this 1.5 percent of the genome where bonobos are closer to us, and the 1.5 percent of the genome where chimpanzees are closer to us.”
Prüfer notes the genetic differences between the bonobo and chimpanzees may be the result of the apes’ distinct habitats. In the wild, bonobos can only be found in the Democratic Republic of Congo. “The formation of the Congo river, about 2 million years ago, probably divided up the ancestor in two different parts,” Prüfer said, “the one below the Congo river, which are the bonobos, and the chimpanzees, which live north of the Congo river; and this geological event essentially divided up this ancestor and formed these two different species.” Indeed, it has long been thought that the creation of the Congo river about two million years ago was responsible for the divergence of the species. And the new analysis certainly seems to support that theory, with no significant signal of interbreeding detected in the DNA of the apes. “It seems there was a very clean split,” said Kay Prüfer.
But as similar as their genomes are, bonobos and chimps do display some quite diverse behaviors. Chimps are very territorial and resort to aggressive actions to resolve conflicts, whereas bonobos are more placid and will use sex as a tool to settle their differences. The researchers want to learn something about the origin of these behaviors, and the degree to which they are influenced by genetics. “If you look at bonobos, chimpanzees and humans, what you can see is that there are some specific characteristics that we share with both of them. So, for instance, the non-conceptive sexual behavior is a trait that is certainly shared with bonobos, while the aggressive behavior, unfortunately, is also a trait that is shared with chimpanzees. In a way, it is a question of what the ancestor of all three looked like. Which one actually evolved the new trait here?” To get at some answers, scientists plan to look more deeply at those parts of the genomes where humans share more similarity to bonobos or chimpanzees. “For the chimpanzees, bonobos, and humans – the common ancestor of all three lived somewhere around 4 to 5 million years ago,” Prüfer said, contradicting the Young Earth Creationism of Ken Ham and Zakir Naik.
Richard Ruggiero, chief of the Asia & Africa branch at the U.S. Fish & Wildlife Service, believes the mapping of the bonobo genome is an important development. “It’s always interesting to have genetic proof of what people see in the field. It’s exciting to get this information that it [the bonobo] shares its genetic proximity to people and, of course, to chimpanzees, and the differences that we see with how chimpanzees have adapted to their environment and how bonobos have adapted to theirs. As the author points out, they were thought to be represented by a common ancestor and how the selective pressures have genetically changed these animals in ways that are now becoming increasingly visible. This scientific paper is a wonderful step forward not only in science but in that important first step of awareness about the plight of this species and what we as humans need to do to ensure that our own activities don’t wipe them out.”
Working with local communities, several conservation groups have set up protected areas in the Congo for the bonobos. And a large bonobo sanctuary (Claudine Andre) just outside of Kinshasa is helping to re-introduce orphaned bonobos back into the wild, explained Voice of America. Greenpeace would probably agree with Ruggiero, Andre and Prüfer.