The Lycaeides species complex is a polytypic group of butterflies (Family Lycaenidae) that is an ideal system for investigating the mechanisms driving the evolution of reproductive isolation because this group is currently undergoing differentiation. These butterflies exhibit extensive morphological and ecological variation. Across North America, evidence for multiple Pleistocene-aged refugia is evident from phylogeographic patterns of mitochondrial DNA (mtDNA). Where these refugial populations meet, gene exchange via hybridization has occurred. In these zones of contact, called suture zones, we find evidence of mtDNA introgression and multiple potential cases of homoploid hybrid species which have rarely been demonstrated in animals. Ecological field experiments and population genetic analyses are used to investigate the evolution and maintenance of morphological and ecological variation and the mechanisms by which reproductive isolation evolves.

For more info: Nice & Shapiro 1999, Nice et al. 2002, Fordyce et al. 2002, Fordyce & Nice 2003, Nice et al. 2005

Pipevine Swallowtails, Battus philenor, are at the center of a mimicry complex in North America. These butterflies are specialists on pipevine plants (Aristolochia sp.) and sequester aristolochic acids which larvae obtain by eating the plants. These toxic alkaloids protect caterpillars and adults from predation. Research on the pipevines is focused on understanding geographical variation in plant toxicity and larval sequestration ability and consequences, life history variation including clutch size and diapause dynamics, the adaptive significance of larval color variation and the phylogeographic history of this species in North America.

Most of this research has been done in collaboration with Jim Fordyce at the University of Tennessee, Knoxville.

For more info: Fordyce & Nice 2003, Fordyce & Nice 2004, Fordyce et al. 2005, Fordyce 2006, Nice & Fordyce 2006.

The neotenic salamnders of the genus Eurycea are endemic spring dwellers in the Texas hill country. This genus contains several rare species including the federally threatened San Marcos Springs salamnder, E. nana. These salamanders are threatened by lowering aquifer levels resulting from increased water consumption by hill country residents and drought. In cooperation with the US Fish and Wildlife Service National Fish Hatchery and Technology Center, we are examining molecular genetic variation in E. nana and closely related salamanders in the hill country to understand the patterns of connectivity among populations. Specifically, do Eurycea salalmanders use aquifers or rivers as conduits for dispersal? What proportion of salamamnder populations persist below ground in the aquifers? What are the biogeographical features of the landscape that facilitate or limit gene flow? The answers to these questions will inform management decisions for these salamanders. Master's student Lauren Lucas is principally in charge of this project.

We are examining genetic variation within the endangered Comal Springs riffle beetle, Heterelmis comalensis (Family Elmidae), to assess population structure within the species. The Comal Springs riffle beetle is a narrow endmic to the Texas Hill Country and is found at only six localities in two spring complexes: the Comal Springs complex (Landa Lake, New Braunfels, TX) and the San Marcos Springs (Spring Lake, San Marcos, TX). We are using molecular genetics tools to estimate the degree to which the six known localities of this endangered species are differentiated or isolated from each other. We are also examining genetic variation and structure within three congeneric species: H. glabra, H. obesa and H. vulnerata. Data from these species will be used as a basis of comparison with H. comalensis. Data from this project will provide a greater understanding of the patterns of gene flow among endangered populations and will consequently inform management strategies for these endangered beetles. For more on endangered spring invertebrates, click here.