Humans and chimps share a surprising 98.8 percent of their DNA. 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.SEM image of human chromosomes, showing centromeres and chromatids
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 6 or 7 million years ago
- As humans and chimps gradually evolved from a common ancestor, their DNA, passed from generation to generation, changed too
Same Genes, Behaving Differently
Although humans and chimps have many identical genes, they often use them in different ways
Slightly Different Genes
Chimpanzee immune system is surprisingly similar to ours
Banding Patterns
The light and dark bands on these chromosomes, created by a laboratory dye, reveal similarities and differences among human, chimp and mouse DNA.
- Human and chimp X chromosomes both contain about 1,100 different genes, or sets of instructions. Each gene affects a particular trait in the body.
… and Yet So Different
If human and chimp DNA is 98.8 percent the same, why are we so different?
- Numbers tell part of the story.
- Each human cell contains roughly three billion base pairs, or bits of information.
- Just 1.2% of that equals about 35 million differences.
