The nematode Caenorhabditis elegans presents us with an evolutionary puzzle. It is small, widespread and capable of rapid population growth. Yet, contrary to expectations, genetic variation is very low. This research addresses the reasons behind this paradox. Two key processes might contribute to the lack of polymorphism: population structure and mating system. By employing microsatellite and DNA sequence data, we propose to estimate population structure and gene flow. Decay of linkage disequilibrium will be used to estimate selfing rates. Populations to be collected locally, as well as publicly available strains will be used. A major difficulty in isolating C. elegans from soil lies in distinguishing it from other morphologically similar species. We have developed a novel technique for species diagnosis, which is more rapid than conventional methods. This technique will vastly enhance the appeal of C. elegans as a model organism for evolutionary geneticists. The study will contribute a great deal to our understanding of the evolutionary history of C. elegans, about which very little is known presently.
