The central goal of research in the Williams lab is to determine the molecular and evolutionary forces that have caused diversification and stasis in genome evolution. We aspire to provide experimental evidence for causative links among genotype, phenotype and fitness; and thus, identify the 'smoking guns' responsible for evolution in action. Most of the work in our lab takes advantage of the experimental power afforded by the model systems Saccharomyces cerevisiae (a.k.a. baker's or budding yeast) and the computational artificial life platform AVIDA. In order to address questions of interest, our methodological approaches combine molecular biology, experimental evolution, molecular evolution, microbiology, ecological genetics, bioinformatics, comparative genomics, cell biology and biochemistry.

Typically, work in our lab first involves the identification of genes or phenotypes with interesting patterns of molecular evolution, i.e. variation within species, rapid evolution among species, conserved protein residues with known disease effects from mutagenesis studies, or no evolutionary change over long evolutionary time scales. Some genes/phenotypes are of interest because they evolved in our lab (in silico or in vivo), some are from natural populations, and some for their potential value in industrial or biomedical applications. We often manipulate the genome directly in order to examine the effect of each mutation, even those that resurrect ancestral (ancient) genes, across genetic backgrounds and environmental conditions. We identify the mechanism behind the mutational effects with genetic, molecular and biochemical approaches. Finally, we quantify the fitness effect of mutations in ecologically relevant environmental conditions.

Previous work has ranged from adaptive gene duplication and gene family evolution, to conservation genetics, mechanistic costs of gene expression plus codon bias, the determination of fitness landscapes with epistasis, and compensatory adaptation.

Our current projects involve experimental phylogenetics, applied evolutionary genetics in synthetic biology and metabolic engineering (e.g., biofuel production, transgene stability), functional genomics in hyenas, butterflies, and salamanders, and proteome structure/function evolution.