'Perception' Gene Tracked Humanity's Evolution, Scientists Say

'Perception' Gene Tracked Humanity's Evolution, Scientists Say: "Hahn said this 'evolutionary burst' is responsible for differences in gene expression rates. When induced, the human prodynorphin gene was 20 percent more active than the chimpanzee prodynorphin gene. Past research has also observed variation in expression levels within humans.
This report supports a growing consensus among evolutionary anthropologists that hominid divergence from the other great apes was fueled not by the origin of new genes, but by the quickening (or slowing) of the expression of existing genes."