Insights into the evolutionary process from patterns of DNA sequence variability.

Studies of DNA sequence diversity, particularly in Drosophila, reveal both the complexity of natural selection and the importance of the interaction of natural selection and variation in rates of recombination within genomes and between species in determining levels of sequence variability in different genes and different species. The impact of both adaptive and deleterious mutations are evident. Extension of these types of studies to other organisms has begun in earnest.