The Geological Sciences Colloquium Series presents Davey Wright on “Phenotypic Diversification and Evolutionary Radiation in Paleozoic Crinoids” on Nov. 18 at 4:10 p.m. in Clippinger 205.
Dr. Davey Wright
Wright is a Presidential Fellow at The Ohio State University School of Earth Science.
Abstract: The application of model-based approaches to estimating evolutionary trees (i.e., phylogenies) and the development of phylogeny-based statistical methods have greatly expanded paleobiological research programs investigating the tempo and mode of morphologic evolution. For example, the direct study of character changes along branches of time-calibrated phylogenetic trees provides high-resolution insight into macroevolutionary dynamics and complements analyses of morphospace occupation through time. Despite obvious advantages, phylogeny-based analyses of evolution are subject to numerous biases that may affect the outcome of comparative methods. Potential biasing factors include: incorrect tree topologies and branch lengths, the presence of ancestor-descendant relationships, and the incompleteness of the fossil record. To help overcome these challenges, phylogenetic paleobiologists are increasingly (1) incorporating more realistic models of diversification dynamics and incomplete sampling when inferring phylogenetic relationships, and (2) applying comparative analyses to many alternative time-calibrated phylogenies. In this talk, I discuss the relationships between phylogeny-based rates of morphologic evolution, taxonomic diversification, morphospace occupation in the ~200 million year evolutionary radiation of Paleozoic crinoids. Results indicate phenotypic diversification is more complex than models commonly assumed in comparative biology, at least over geologic timescales—highlighting the need for continued synthesis between fossil and phylogenetic approaches to macroevolution.
Comments