23. the Same Gene Between Humans and Chimpanzees

Humans and chimpanzees share about 98.7 percent of the same gene 1) ______ and most of that small difference may be in the brain, which is much more 2)_____ in people than in the ape, researchers say.

Chimpanzees are more closely related to humans than any other primate. The two are thought to have shared a common 3) ____ 5 million to 7 million years ago , although just what that ancient primate looked like is unknown. Since then, chimps and humans have 4) ____ separately, with humans developing a brain about twice the size of chimps.

A study found that although the chimp’s tissue and blood 5) _____ that of humans, the gene activity in the animal’s brain was more like that of monkeys. Humans are expressing more 6) ____ differences in the brain and that is what enables us to do what we can do.

Researchers said the genetic comparison of chimps and humans might lead to better 7) ___ for human disease. With an understanding of the differences between humans and chimpanzees, scientists may be able to learn more about the genetics 8) ____ diseases that harm humans. The researcher noted that chimps can become 9)____ with HIV, the AIDS 10) ______, and never get sick.