The geographic and morphologic response of species and communities to their climate and environment

• Main Author: Lawing, A Michelle
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01.01.2012
• Subjects: Bioinformatics; Climate Change; Paleoecology
• ISBN: 1267911263; 9781267911261

How species will cope with the effects of anthropogenic change is now a subject of great concern. The response of species to climate change can be measured geographically with species distribution models or morphologically with community-averaged traits. In this dissertation, I integrate rich geological and paleoclimatic data with an evolutionary concept of climatic niches to quantify the responses of species to climate change. I show that biotic interactions, namely competitive exclusion, along with climate tolerances, can shape species borders, exemplified by sister species within the rattlesnake genus Crotalus. Projecting phylogenetically informed species distribution models over the last three glacial-interglacial cycles indicates that species within Crotalus were not able to adapt as fast as climate changed. The rate of geographic displacement of suitable habitat over the next century will be two to three orders of magnitude faster than it was over the last 320 ky. A deep time perspective of spiny lizard (Sceloporus ) response to climate change, early Miocene to present, shows that origins, diversification, and subsequent species richness are not coincident in geographic space. Instead, the first lineages to diverge tracked their habitat by moving south as the climate cooled after the Miocene climatic optimum and evolved adaptations such as viviparity to cope with the new climates. Species response to climate change can also be measured through the interaction between environments and morphological traits. I describe a community level trait-environment association in North American snakes and demonstrate that historic changes in community-averaged traits track the changes in macrovegetation. This dissertation demonstrates that geographically explicit models integrating data and methods from geology, ecology, evolution, and climate science provide a deeper understanding to the biology of climate change. These models explicitly address how species responded to climate change in the past to inform expectations of how they will respond in the future.