The Influence of Late Quaternary Climate Change on the Ecology and Evolutionary Dynamics of Small Mammalian Herbivores

University Of New Mexico, Albuquerque NM

Investigators

Abstract

0212370 Smith This research investigates the evolutionary response of woodrats to temperature change over the late Quaternary. The project involves work at cave sites in the southwestern United States, using fossilized woodrat middens or debris piles. Middens consist of plant fragments, fecal pellets and other materials embedded in crystalized urine ("amberat"); when sheltered in caves they persist for thousands of years. Measurements of radiocarbon-dated fecal pellets are used to estimate body size; for most mammals, size is sensitive to environmental temperature. Over the next year, we will investigate a number of potentially problematic sampling and statistical dimensions of our study system, including conducting studies with modern animals to examine midden deposition and composition. Organisms may respond to anthropogenic climate change by adapting or going locally extinct. However, the timing, magnitude and nature of such responses remains unclear. The past ten thousand years are arguably the best proxy we have for understanding the likely effects of anthropogenic climate change. By examining different species of small rodents at different locations within their range over the late Quaternary, and estimating the thermal thresholds at which different types of evolutionary responses occur, we may be able to better understand how future climate change will impact mammalian populations.