This research utilizes complementary phylogenetic and population genetic information to infer modes of speciation in the cave spider Nesticus. The nesticid spiders of the Appalachian region are a recently diverged, species-rich lineage that provides an excellent system for studying both the geographic and populational contexts of speciation. The sister-species relationships of Nesticus will be estimated, and in combination with biogeographic evidence from other cavernicolous clades, will define how historical geology and geomorphology have influenced patterns of taxonomic diversity. To complete the analysis, research efforts will be directed at assessing how the population genetic attributes of the species under study might have influenced the speciational process. To this end, the ancestral population structure of phylogenetically defined parental species will be characterized, along with the type of sampling event which gives rise to daughter species. This historical inference will be derived from a comparative analysis of the amount, the rate of change, and the geographic pattern of genetic variation for mtDNA and nuclear DNA genetic systems.
