Hi Ba2 -- I’ll let the experts answer that question.
In Human Population Genetics (published by Wiley-Blackwell 2012), by John H. Relethford (Ph.D. biological anthropologist), the author tells us that “numerous genetic studies have shown that humans and African great apes (gorilla, chimpanzee, and bonobo) are more closely related to each other than either is to the Asian great ape, the orangutan (page 96).
The author goes on to say that “it is clear that humans are somewhat more closely related to the chimpanzee and the bonobo than to the gorilla.”
Our closest living evolutionary relatives today are the common chimpanzee and the bonobo, and are separated from us by at least five million years. Although the name “chimpanzee” is sometimes used to refer to both species together, it’s usually understood as referring to the Common Chimpanzee, while “Pan paniscus” is usually referred to as the Bonobo.
Evidence strongly suggests that humans originated in Africa. Most estimates have put the divergence in the lines that led to humans on one hand and chimpanzees and bonobos on the other at around 6-7 million years. It is likely that the population of last human/chimp common ancestors was fragmented, with reproductive isolation occurring between the sub population that ultimately led to humans from that which led to chimps and bonobos.
At Ohio State University, researchers sequenced the bonobo genome and compared it to the genomes of chimpanzees and humans. The study, The Bonobo Genome Compared With The Chimpanzee and Human Genomes, published in Nature magazine last year.
The authors found that more than 3 percent of the human genome is more closely related to either the bonobo or the chimpanzee than the two apes are to each other, which indicates that the three species share a complex evolutionary relationship.
According to the Bonobo Conservation Initiative, bonobos and humans share 98 percent of the same genetic make-up.
Here’s a simple phylogenetic tree that shows the divergent lines of humans, chimps and bonobos. LCA stands for “last common ancestor.”