This project exploits the close relationship between a mammal (American pika, Ochotona princeps) and five of its intestinal parasites to explore the genetic effects of climate change on montane organisms. Pikas are climate-sensitive, and their population distribution, size, and structure changed dramatically as global climate warmed following the last glacial maximum 18,000 years ago. The host-specific parasites of pikas tracked their hosts throughout this period and provide independent views of the same population history. Combined, these views will help to resolve questions regarding climatic effects on barriers to gene flow, population size fluctuations, and modes of colonization. Pikas and parasites will be collected from 40 populations distributed across North America's intermountain west, and research questions will be addressed by examining DNA sequence variation throughout the range of each species.
Pikas are indicators of healthy high-elevation ecosystems; therefore, their responses to historical climatic change have important implications for predicting the effects of current climate warming. This study is also unique in that it examines genetic variation across a full host-parasite assemblage. No comparable data set currently exists. Lastly, this work is yielding data on cryptic diversity and species distributions that are critical for monitoring biological diversity. Preliminary collections include at least one species of parasite previously unknown to science.
