Many traits of primary interest in plant and animal improvement programs and in conservation biology are affected by a large number of genes with relatively small individual effects. This often means that relatively large germ plasm banks must be maintained at considerable cost to insure that all potentially useful alleles are maintained in a population or species. Theoretical work of W.G. Hill at the University of Edinburgh raises the question of whether this is a necessary practice or whether, alternatively, new mutations can be counted on to supply genetic variation needed for future change. This project is designed to focus on two aspects of the Hill work using a laboratory organism (the flour beetle) to test the ideas. Selection for a quantitative trait (body size) will be used to determine the amount of useful variation that is generated by new mutation. Much of the existing dogma suggest that most mutational variation is likely to be deleterious rather than helpful. The second aspect of the work will evaluate how important it is to apply constant selection pressure to utilize any new mutational variation that might otherwise be immediately lost since the new mutations will be at a low frequency in the population. The importance of population size in capitalizing on the effects of new mutations will also receive considerable attention.
