Has recent climate change caused a genetic bottleneck in a Sierra Nevada population of the bushy-tailed woodrat?

Many montane species respond to climate change by shifting their range upslope as temperatures at lower elevations increase. An elevation range shift causes a range contraction that may result in a population bottleneck. Joseph Grinnell surveyed the fauna along the Yosemite transect from 1914 to 1920. In 2003 Craig Moritz and his colleagues began to resurvey the Yosemite transect to assess the faunal change during a century of climate change. The bushy-tailed woodrat suffered severe range contraction and population bottleneck between the two surveys. I will use evolutionary models to determine if the population has suffered a genetic bottleneck