TIME, STRATIGRAPHY, AND FOSSIL PHYLOGENIES: RE-EVALUATING THE USE OF TEMPORAL DATA IN PHYLOGENY RECONSTRUCTION AND TRAIT EVOLUTION

The ability to estimate hypotheses of evolutionary relationships (i.e., phylogenies) and the development of tree-based comparative methods to study character evolution has greatly expanded research programs in paleontology. However, the ability to estimate patterns of character evolution and phylogenetic relationships are not generally independent of one another. Of particular concern for paleontologists is that incomplete and/or time-heterogeneous sampling of fossil morphologies may influence either estimate. Rather than ignore temporal information, a more productive approach might involve explicitly incorporating time-stamped character data to more fully take advantage of the broad spectrum of patterns arrayed in the fossil record.

Although geologic data are routinely used to calibrate molecular phylogenies estimating divergences among extant species, the use of temporal information in phylogeny reconstruction has had a somewhat contentious history in paleontology. Nevertheless, the intensity and temporal distribution of fossil samples make predictions regarding the probability of phylogenetic hypotheses, divergence times, and rates of character evolution. The emerging field of phylogenetic paleobiology increasingly utilizes model-based approaches, such as fossil-tip dating methods, to simultaneously account for diversification dynamics and incomplete sampling when inferring phylogenetic relationships.

In this talk, I re-evaluate the use of temporal data in phylogeny reconstruction and trait evolution. Throughout, I provide empirical examples illustrating recent conceptual and analytical advances in phylogenetic paleobiology emphasizing the deep time fossil record of Paleozoic crinoids.