The New York Times Science section has an excellent evolution special this week. Of particular interest is Nicholas Wade's article on the very recent evolution of human populations. There is more and more evidence that culture has shaped the human genome. Also fascinating is Cornelia Dean's inquiry into what has happened to the human soul. Evolve locally, Science of the Soul.
Two variants of the genes ASPM and Microcephalin may make it easier to learn tone languages. If you have the tone-versions, as do most speakers of Chinese (and other languages such as those found in South East Asia and sub-Saharan Africa), you may be more adept at learning languages that distinguish words with pitch as opposed to those that don't. This is the first time it's been shown that possessing a particular form of gene, let alone two, may impact the way we learn language. The dogma has always been that we are all born with precisely the same genetic program which builds exactly the same neural equipment for language. The Times, Scientific American, PNAS.