The proposed research is a theoretical investigation into the causes of genetic variation in natural populations and the changes that occur in this variation as a result of natural selection. Genetic variation is measured at many different levels, ranging from DNA at the lowest level to the overall morphology of the organisms at the highest. At each of these levels there is a substantial amount of genetic variation, although the forces that are responsible for this variation remain a mystery. It is the intent of the proposed research to investigate the relative roles that natural selection, mutation, and genetic drift might play in the maintenance of genetic variation in natural populations. Unique to this research is the hope that a comprehensive theory will emerge that allows the variation at all levels to be explained within the context of a single theory, rather than the current state where a different theory is used for each level of variation. Evolution not only maintains variation, but it also changes the genetic state of a population. The most familiar expression of this is the changes in morphology seen in the fossil record. A second goal of this research is to provide a theory to explain these changes in morphology that is compatible with our understanding of genetics and the forces that maintain variation. The proposed research will not only provide insights into the genetic bases of evolution in natural populations, but may also help to understand some of the problems facing human populations. Humans share with other organisms the property of having an extraordinary amount of genetic variation between individuals. This variation is undoubtedly at the root of some of the differences that are observed between individuals in such important attributes as disease susceptibility. Yet we are as ignorant of the cases of variation in human populations as we are of the variation in natural populations. The insights gained from this research will hopefully provide a better understanding of the role of genetic variation in the human condition.
