It has sort of been thought that evolution of modern humans had stopped when humans with modern characteristics first appeared. Now a geneticist, Gregory Cochran, and an anthropologist, John Hawks, state that evolution has been proceeding faster in the last ten thousand years than in the presumed "origin" of modern humans 160-200 thousand years ago. In an article in World Science, they state that modern human brain cases have continued to change dramatically. According to the article:
Anthropologist Jeffrey McKee of Ohio State University said the new findings of accelerated evolution bear out predictions he made in a 2000 book The Riddled Chain. Based on computer models, he argued that evolution should speed up as a population grows. This is because population growth creates more opportunities for new mutations; also, the expanded population occupies new environmental niches, which would drive evolution in new directions.
This is exciting, and may open doors for many different areas of research. It also puts a bit of a crimp in the "rapid replacement" model of modern humans origins. Put simply, if evolution has not slowed down with the advent of modern humans, then it is more of a continuum than was previously thought.
Hat tip to Glenn Reynolds.