Geological control underlying desert tortoise speciation Gopherus agassizii and G. morafkai are physically separated by the Grand Canyon in Arizona today. The incision age (and inferred speciation age) of the Colorado River through this Canyon, however, varies across the landscape and has been a source of contention. I hope to use incision and other information to better inform the speciation age and process of these hallmark desert species, in what has become a classic vicariant speciation story.
Genes underlying niche adaptation in desert tortoises (Gopherus spp.)
Species distribution models were recently developed to differentially describe the niche of Agassiz’s desert tortoise (Gopherus agassizii) and Morafka’s desert tortoise (Gopherus morafkai), and their sympatric zone. I’m working with Drs. Timothy Webster to identify the genes and gene variants across the genome that segregate with these ecological preferences. I am also developing paleohabitat distribution models for these species to assess confounding demographic scenarios and test niche conservatism over time. We hope to better answer the question: what makes a tortoise?