When I was teaching physical, or biological anthropology, I was often asked, “Is our species still evolving?” Sometimes, the question was posed to me a bit more forcefully, as a challenge to the reality of evolution, itself. Some students would ask, “If evolution occurred, why aren’t we humans still evolving?” (And those were some of the easier questions I fielded in my thirty something years of teaching anthropology prior to my retirement several years ago due to an autoimmune disease). What made these particular queries so simple to address is, first, the overwhelming evidence that we humans are still undergoing evolutionary change. About three years ago, for example, University Chicago Professor Jonathan Pritchard and his colleagues identified a number of genes that have been undergoing changes in the last 10,000 years – among them genes related to skin color, taste, smell, and brain structure. Such changes in gene frequencies over time provide classic examples of evoluionary change. Of course, we evolve in other ways – we make alterations in our behavior and these, in turn, are often proceeded by enviromental shifts.
Although space and time constraints …