Chimps cannot talk because of the genetic code. The genetic code in humans and chimps differ in their genes function. Chimpanzees share most of their DNA with their human brothers. Chimps and humans shared percentage range from 95 percent 98.5 to percent.
Dan Geschwind, a professor at King’s College London, found out that a gene called FOXP2. FOXP2 is the gene which looks similar in chimps and human. FOXP2 plays an important role in human speech. 4 million to 7 million years ago FOXP2 looked similar in many animals right up to the time the human lineage split off from the chimpanzee.

FOXP2 actually means that it affects the activity of other genes. Humans and chimp brain tissues were analyzed of what FOXP2 actually does?

FOXP2 actually produced two amino acids extra as produced by the gene of the chimp variations in brain structure that may be involved in human language. Research shows that the amino-acid composition of human FOXP2 changed rapidly around the same time that language emerged in modern humans.