GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 84-65
Presentation Time: 9:00 AM-5:30 PM

MAMMAL DIVERSIFICATION ACROSS DYNAMIC LANDSCAPES—A CASE STUDY WITH NORTH AMERICAN RODENTS


BADGLEY, Catherine, Department of Ecology and Evolutionary Biology, University of Michigan, 1109 Geddes Avenue, Ann Arbor, MI 48109, DAVIS, Edward, Department of Geological Sciences, University of Oregon, Eugene, OR 97403, FINARELLI, John A., University College Dublin, Dubline, Ireland, RIDDLE, Brett R., School of Life Sciences, University of Nevada Las Vegas, 4505 Maryland Pkwy, Las Vegas, NV 89154-4004, SMILEY, T.M., Oregon State University, Corvallis, OR, TERRY, Rebecca, Integrative Biology, Oregon State University, Corvallis, OR 97331 and YANITES, Brian J., Department of Earth and Atmospheric Sciences, Indiana University, 1001 East 10th Street, Bloomington, IN 47405, cbadgley@umich.edu

Understanding causal mechanisms behind diversification and range dynamics requires integrating information from the fossil record with phylogenies, functional traits, and the geographic distributions of living species. Our research group of biodiversity and earth scientists investigates how biogeographic processes have influenced the present and past diversity of mammals in the context of dynamic landscape history, focusing on the diversity and distributional dynamics of rodents in western North America over the last 30 myr. Living rodents, which represent nearly half of present-day mammal diversity, show a strong topographic diversity gradient from the tectonically quiescent Great Plains (lower diversity) to the tectonically active montane west (higher diversity). Rodents have an excellent fossil record over these same landscapes, and this record indicates that the topographic diversity gradient is not constant, but has waxed and waned over the Neogene.

As a research collaboration network (RCN), we comprise earth scientists, paleobiologists, evolutionary biologists, and ecologists analyzing the influence of tectonic, topographic, and climatic history on speciation, extinction, adaptation, and geographic-range shifts of rodents. Over the last 30 myr, western North America experienced profound changes in surface area, topographic complexity, and environmental gradients. Our research has demonstrated, for example, that rodent diversity tracked rates of extension in the Basin and Range over the last 30 myr. Ongoing research includes (1) collaborations with geophysicists, geomorphologists, and paleoclimatologists to infer the changing configuration of topographic connectivity and complexity, and climatic gradients, and (2) analyses of speciation and extinction, persistence, and adaptation for cohorts of Miocene rodents with respect to evolutionary history and ecological attributes. RCN goals are to improve our understanding of the biogeographic responses of rodents to changes in landscape and environmental gradients both for the Neogene and for living species in relation to current climate change.