Developing an understanding of the origin and maintenance of sexual reproduction is currently considered one of the foremost theoretical problems of evolutionary biology. Why do organisms continue to "waste" resources and "sacrifice" more rapid population growth by the production of males? Learning the answers requires studying the opposite life-history strategy, thelytokous parthenogenesis, a process in which female progeny are produced from unfertilized eggs. Previous studies showed that the oribatid mite taxon Nothroidea contains the largest known grouping of parthenogenetic animals; many of the included families contain no sexual species at all. For a long time it has been thought that without sexuality an organism cannot create the genetic flexibility necessary to survive and evolve; supposedly, it is an evolutionary "dead-end" at least in the long term. The investigators will use modern methods to show that populations of these parthenogenetic mites do have substantial genetic variability. With these results, combined with previous studies of evolutionary relationships among these mites, the investigators will show that parthenogenesis is not always a simple, evolutionary short-cut to eliminate the "waste" involved in sexual reproduction. If whole groups of animals have evolved in the absence of sex, then the future search for the underlying mechanism should indirectly increase our understanding of sexual reproduction itself.
