Assistant Professor

Biological Sciences

Lehigh University (Bethlehem, Pennsylvania)

I am interested in the origins and maintenance of biological diversity at all hierarchical levels of organization (i.e. - genotype to phenotype).

My research focuses on understanding how adaptive phenotypic variation arises and is maintained in natural populations. In particular, I am interested in the link between divergent natural and sexual selection on traits involved in sexual signaling and mate recognition and the origins of barriers to gene exchange between closely-related populations. Hybrid zones are ideal settings to address such questions because they present opportunities to study the effects of gene flow, selection, and recombination in nature and, thus, provide insights into the genetic, behavioral, and phenotypic changes that occur early in speciation.

Although I have studied the origins of adaptive phenotypes in a number of evolutionary systems (predominantly insects), much of my previous work has been aimed at understanding the origins of mimicry and wing pattern variation among hybridizing populations of mimetic and non-mimetic admiral butterflies in the Limenitis arthemis-astyanax species complex (Figures 1a and 1b).

Current efforts in the lab are directed towards identifying the genes underlying the mimicry polymorphism is this system using a combination of functional genetic and genomic approaches. Ongoing projects include: 1) QTL and association mapping to identify genome regions underlying wing pattern differences between mimetic and non-mimetic phenotypes, 2) functional genetics of larval wing discs (cDNA library construction, EST sequencing, and, ultimately, gene expression studies) to identify candidate patterning loci, and 3) Analyses of SNP variation associated with previously identified patterning genes from Drosophila and other lepidopteran systems (e.g. - Heliconius, Bicyclus). In addition, we are conducting no choice mating trials to test for evidence of assortative mating and/or reinforcement.