We became interested in the evolutionary potential of asexual fungi through a study of Penicillium species, which showed that loss of sex is an evolutionary dead end. This research led us to use population genetics to study the modes of reproduction of an apparently asexual fungus, Coccidioides immitis. We are now looking at gene flow and speciation in this pathogen, and think that we have found that it is really two species. We think that mycorrhizal fungi are good candidates, and are working on the most widespread mycorrhizal ascomycete, Cenococcum geophilum. We are also extending our population studies to lichens, while continuing phylogenetic studies of selected groups, such as powdery mildews and economically important Penicillium species.
Fungi can be cryptically sexual.
Evidence from population genetic studies suggests that fungi previously thought to be asexual are actually sexual in nature. The consequence of sexual recombination is the random association of loci that are not physically linked. Population genetic tests were employed using Coccidioides immitis, a human pathogenic fungus with no known sexual state, to see if loci are non-randomly associated. Overall, these two tests strongly suggest an inheritance pattern based on sexual recombination. Some recent publications include Fisher, M.C., Koenig, G.L., White, T.J. and J.W. Taylor. 2000.