Chimpanzee (Pan troglodytes)

There are only 50 human genes that have no homolog in chimps. Differences between the two species are, therefore, due more to changes in gene regulation.

As recently as five million years ago, humans and chimps shared a common ancestor. A chimp possesses approximately 20,000 to 25,000 genes… approximately the same number as humans. Of that total, there are only 50 human genes that have no homolog in chimps. Differences between the two species are, therefore, due more to changes in gene regulation. Identifying genes that are divergent between humans and chimps should be helpful in understanding disease susceptibility. For example, chimps do not suffer from some human diseases such as AIDS and malaria. A comparison of the two genomes may reveal that there are genetic reasons for this and result in new ways of treating and preventing human disease.