Molecular evolutionary ecology aims to understand the mechanisms underlying adaptive traits as well as their evolution. In my fungal evolutionary ecology program I use a variety of fungal systems to evaluate both 1) how targeted traits contribute to fitness and 2) the evolutionary trajectory and/or history of the traits. Filamentous fungal systems are particularly conducive to addressing these fundamental questions in evolutionary ecology through laboratory manipulations (e.g. fitness assays, competition studies, artificial evolution experiments), population analysis and comparative genomics. Briefly, specific characteristics that make these systems so appropriate include:

• - short generation times
• - many can be maintained and manipulated under replicated conditions in the lab
• - production of distinct quantifiable developmental forms (e.g. mycelia, conidia, ascospores)
• - polymorphic traits with presumed adaptive value (e.g. secondary metabolite production) with unknown roles
• - many form intimate associations with other species (e.g. plant hosts) resulting in quantifiable phenotypes
• - many systems are conducive to molecular manipulation
• - a few very well developed systems have genome sequence data available

I believe that taking advantage of the resources available from a variety of different fungal systems allows us to zero in on a better general understanding of how traits (most of which are extremely well understood genetically) contribute to fungal fitness. As we accumulate data and resources associated with fungal genomics efforts it seems reasonable to make use of them to tackle questions in other fields of biology. Ultimately, I hope that our efforts using this approach will pioneer new understanding of the genetic mechanisms behind some of the dogma in evolutionary ecology (e.g. predicted trade-offs between reproduction, growth, and defense). Also, it is my interest to determine whether adaptive divergence in intra and interspecific fungal lineages is a associated with selection acting on particular types of genes (e.g. transcription factors).

Currently there are three lines of research on-going in our laboratory. 1) We study the genetic basis of loline alkaloid expression in the fungal endophyte Epichloë festucae . This sexual endophyte is an excellent model for all the very closely related endophytes of cool-season forage grasses (Epichloë and Neotyphodium spp.) We have extended the study of the locus (a cluster of 9 ORFs) to four closely related endophytes, thus allowing us to make predictions about the evolutionary of this trait, which is unique to endophytes. 2) We are examining the structure of a Texas population of Aspergillus flavus. Examination of several types of genetic markers (AFLPs, RFLPs, and sequence from a single gene) has revealed patterns consistent with recombination within the local population. We intend to confirm this by looking at the distribution of mating type loci within the population. Taken together with the work we have done to demonstrate a fitness advantage associated with progression along the AF/ST pathway using A.nidulans mutants, there are some clear implications for use of highly competitive atoxigenic isolates for biological control. 3) We are using a quatitative genetic analysis approach with life-history traits for the model fungus Neurospora crassa. Not surprisingly the traits of perithecium size and number, and asocspore size, shape and number exhibited very high heritability values. Furthermore, the variation in these traits does in fact correlate with fitness differences in different environments (eg. Ascospore germination under different temperatures). The obvious extension of this work will involve artificial selection for traits, identification of genes involved in quantitative variation and identification of environmental micro-heterogeneity that supports these distinct phenotypes in nature.