Dr. Michelle Lawing, Department of Ecosystem Science & Management, Texas A&M University
Title: “Null models for the ecometric study of trait-climate correlations at continental scales”
Abstract: The sorting of species along climatic gradients based on traits is a key topic to understanding the impacts of global climatic change in the past, present, and future, as well as the fundamental processes that link ecology and evolution. Trait-based sorting is a complex process involving geographic range changes, selection, extinction, and evolution and requires integration of data from biogeography, phylogenetics, functional analysis, paleontology, and environmental science. Because ecometric analyses are conducted at large spatiotemporal scales, their predictive power is based on statistical correlations whose null distributions have heretofore been largely unstudied. We addressed this problem by constructing null models for the geographic distribution of trait means for North American mammals. We demonstrated 1) extant mammalian assemblage-level traits are geographically sorted along climatic gradients, 2) patterns do not arise spuriously from random, spatial or phylogenetic processes, and 3) traits may be measured in fossil assemblages to reconstruct paleoenvironments.