paleontological pipeline

How should fossils contribute to our understanding of evolution in the age of genomics? As direct windows into ancient phenotypes, biogeographic distributions, and temporal context, fossils offer valuable insight into evolutionary history. Beginning with the description of new species, through to characterizing novel morphological adaptations and phylogenetic analyses, we are interested in learning as much as possible from fossil collections. Fossils mean more with a sense of where they fit in the context of living organisms. Evolutionary relationships are most often reconstructed not through the compilation of morphological data, which readily incorporates paleontological work, but instead through a wealth of molecular (DNA) information. Molecular sequencing continues to rapidly decrease in cost, and so genetic data are being generated very quickly which has led to rapid advancements in phylogenetics. However, it is not yet clear how best to include fossils in phylogenetic reconstruction, particularly when genomic-scale molecular data may far “outweigh” any morphological data signal. We use the social insect fossil record to test methodologies that relate to integrating extinct taxa into evolutionary research that is primarily driven by molecular (DNA) data. Recent projects have focused on the impact of fossil taxa on divergence dating estimation as well as biogeographic reconstruction. Aside from phylogenetic applications, we have also applied morphometric analyses of fossil specimens to evaluate morphological diversity from a quantitative perspective.

3D reconstruction of the ~99 million year old ant Haidomyrmex scimitarus in Burmese amber.

understanding extinction

It is common to focus on the “winners” in biology. That is, the less than 1% of all species which have persisted to the present. While speciation and diversification lead to the species we see today, they are one half of the sculpting force responsible for the composition of biodiversity, equal only to extinction. The study of lost diversity is important as it informs our understanding of what taxa are susceptible to loss and provides more nuanced understanding of what specific factors facilitate survival. Fortunately, the study of ancient insects and lost phenotypes is facilitated by amber fossils, which preserve original organic material with high fidelity. It turns out that both early ants and early termites experienced significant extinction. In the case of ants, many early relatives of modern species possessed adaptations no longer found in insects and have subsequently gone extinct. You can read about some of these "evolutionary experiments" here, here, and here