"Given the recent emphasis on the roles of genes in disease and evolution, we tend to forget that in the short run evolution is driven by differences in fitness among phenotypes, not genotypes. We can learn a lot about the speed and direction of evolution in humans by examining the transmission of phenotypes from one generation to the next. This focus on phenotypes contrasts with the attention recently paid to the signatures that selection has written in the human genome since our last common ancestor with chimpanzees…Less attention has been paid to the possibility that we are currently experiencing natural selection responses to contemporary natural selection."