[DLS] Shuhai Xiao (Virginia Tech)

“A Paleontological Perspective on the Tempo and Mode of Proterozoic Eukaryote Evolution”

The fossil record provides key data for the assessment of the evolutionary patterns and dynamics of biodiversity in the geological past. In this seminar, I will present a narrative of key Proterozoic eukaryote fossils as well as the results from quantitative analyses of paleontological databases. Eukaryotes apparently rose nearly two billion years ago, shortly after the Great Oxidation Event. For much of the Mesoproterozoic and early Neoproterozoic, the diversity of eukaryote fossils increased slowly and remained at a relatively low level. However, it is during this time interval when crown-group eukaryotes first appeared in the fossil record and several major eukaryote clades diverged. Despite their early divergences, these eukaryotes apparently left a limited ecological footprint in the Earth-life system. The subsequent Cryogenian Period represents a major divide in eukaryote evolution. Post-Cryogenian eukaryote fossil diversity increased rapidly, featuring major diversification and extinction events in the Ediacaran Period. The currently available and emerging data from paleontology, phylogenomics, and geochemistry allow us to establish a holistic understanding of and to formulate hypotheses about the interactions between life and Earth during the Proterozoic eon – a formative age in the history of our planet.

EAPS Department Lecture Series —

Weekly talks aimed to bring together the entire EAPS community, given by leading thinkers in the areas of geology, geophysics, geobiology, geochemistry, atmospheric science, oceanography, climatology, and planetary science. Runs concurrently with class 12.S501.

Contact: eapsinfo@mit.edu