DATA LIMITATIONS IN THE INFERENCE OF PALEOBIOLOGICAL PROCESSES: AN EXAMPLE IN HOMININS (Invited Presentation)

The past decade has witnessed many methodological contributions for the statistical analysis of paleontological data. As increasingly sophisticated models and inferential algorithms have become more widely available, their is rapidly becoming the norm in paleobiology. The development of a more statistically robust framework will undoubtedly be an important step in better discerning the evolutionary patterns and processes that shape the biological diversity of living and fossil species from paleobiological data. However, it will also be critical to develop a stronger understanding of the ways in which fragmentary and sparsely-sampled fossil data are fundamentally limited in their ability to inform reconstructions. For instance, given that many emerging approaches focus on analyses of data typically sampled at higher taxonomic levels, one potential issue concerns their ability to meaningfully reconstruct fine-scaled processes. This issue is particularly important when addressing phylogenetic problems such as delineating between speciation modes (budding versus splitting cladogenesis, for example), since inferences may be strongly influenced by the construction of operational taxonomic units (OTUs) and are likely sensitive to the assumption of evolutionary stasis within OTUs. Here, I evaluate the ability of existing parametric phylogenetic methods to inform hypotheses of ancestor-descendant relationships and geographic patterns in morphological and molecular variation from data sampled at the level of morphospecies in hominins. These analyses highlight both the strengths and limitations of emerging parametric approaches in developing a more detailed view of the processes of morphological evolution and speciation in the fossil record and provide insights for future studies.