Research

We study ecological and evolutionary paleontology. Our interests are in the macroecology, phylogeny, development, and evolution of mammals and other vertebrates (sometimes invertebrates too). We have expertise in trait-based ecology, ecometrics, spatial processes, quantitative evolution, morphometrics, and phylogenetics (with a little bit of genomics).

Our research aims to understand how species respond evolutionarily and ecologically to environmental change, one of the great challenges for the 21st century. The paleontological and geological records provide a comparative context to study how life responded to dramatic changes in climate, topography, and oceanic conditions through diversification, adaptation, and extinction. Using these deep-time records, we can measure the rates at which species respond, the factors that tip the balance between adaptation and extinction, and the conditions that lead to environmental collapse and mass extinction. Long-term evolution involves genetic and developmental processes that produce phenotypes, drift coupled with selection on phenotypes to maximize performance, and change in the selective regime as local and global environments change. We utilize this hierarchy to test expectations or assumptions from one of its levels against empirical data from another.

Analysis of spatial environmental sorting of locomotor proportions within species and between clades. (download the paper) Polly et al. 2017, Evolutionary Ecology Research, 18: 61-95.
Analysis of spatial sorting of communities by locomotor traits within species and between clades (from Polly et al. 2017).

Non-linear mapping of genetic parameter space onto phenotypic space filtered through developmental tissue-level interactions (from Polly, 2008 and Polly, 2017).

We use computational and phylogenetic statistical approaches to accomplish this. We necessarily focus on questions that taxonomic diversity, relative abundances, or phenotypic traits that can be fossilized. We also explicitly consider temporal, spatial, and biological scaling because of the fragmentary nature of the fossil record often has greater uncertainty than data from the living world. Our focus is on mammals because the mammalian fossil record is richer, more taxonomically tractable, and better documented than almost any other taxon. We take advantage of new imaging, scanning, and computational tools, and we develop creative new approaches to quantify and analyze morphological data. We also use emerging tools like finite element analysis (FDA) and computational fluid dynamics (CFD) that now allow virtual experiments to compare functional performances of fossil morphologies. Computational and statistical modeling allow us to extrapolate between scales to test predictions from one level of the hierarchy against empirical observations at another.Â