Much of our research is dedicated to the study of the evolutionary processes that shape natural variation in human and great ape populations. Our laboratory is also deeply engaged in the investigation of the pathogenic nature of variation, and how it is involved in causing childhood diseases. The links between these two endeavors are substantial. Mutation is one of the creative forces of evolution; and without it species would not evolve. While rare beneficial mutations can lead to adaptive change and the diversification of life, inevitably some members of our population will bear the brunt of deleterious mutation, and may never have the privilege of reproducing or even surviving to adulthood.