Are You Monkey's Uncle?

Humans share 98.8% of their DNA with chimpanzees. Because gene expression can be turned up or down-similar to the volume on your TV-the same gene can be turned to "high" in a human and "low" in a chimp. The human brain is larger and smarter than that of chimps and gorillas because, although we all have the same genes in the same brain region, these genes are expressed in different "volumes" or amounts. It is these differences that affect brain development and function.