DNA: Comparing Humans and Chimps main content.

DNA: Comparing Humans and Chimps

Part of Hall of Human Origins.

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Photo: Adrian Sumner/Stone/Getty ImagesSEM image of human chromosomes, showing centromeres and chromatids (magnification: x6,100)

The chimpanzee and another ape, the bonobo, are humans' closest living relatives. These three species look alike in many ways, both in body and behavior. But for a clear understanding of how closely they are related, scientists compare their DNA, an essential molecule that's the instruction manual for building each species. Humans and chimps share a surprising 98.8 percent of their DNA. How can we be so similar--and yet so different?

So Much Alike...

Human and chimp DNA is so similar because the two species are so closely related. Humans, chimps and bonobos descended from a single ancestor species that lived six or seven million years ago. As humans and chimps gradually evolved from a common ancestor, their DNA, passed from generation to generation, changed too. In fact, many of these DNA changes led to differences between human and chimp appearance and behavior.