Professor Ellen Thomas of Yale University presents the first lecture of the Tsaihwa “James” Chow lecture series, ‘Life and Death in the Deep Sea: Asteroid Impact and Carbon Cycle Disturbance.’ The deep oceans are the largest habitat on Earth, thus its environmental changes must be global changes. Many species of deep sea benthic foraminifera, unicellular eukaryote organisms, form a shell, and this group is an important of deep-sea meiofauna. Benthic foraminiferal assemblages and morphology provide information on deep-sea environmental change as ‘felt’ by biota, while stable isotope and trace element proxies measured on their calcium carbonate shells provide information on how the environment changed (e.g., temperature, oxygenation, ocean circulation, productivity). Deep-sea benthic foraminifera are efficient dispersers throughout their large habitat due to their mobile propagules, so that one would expect them to be close to immune to major extinction events. Deep-sea benthic foraminifera indeed did not suffer extinction during the asteroid impact (possibly combined with volcanic activity) at the end of the Cretaceous, but were severely affected during the carbon cycle disturbance 10 million years later, at the end of the Paleocene, whereas the reverse is true for planktic foraminifera, which live in the upper water column. I will look into the decoupling of planktic and benthic extinctions, environmental changes during both events, and the effects of varying rates of change on biota. Learn more about Dr. Thomas: https://people.earth.yale.edu/profile/ellen-thomas/about The lecture series is named for Dr. Tsaihwa J. Chow, a geochemist with a long association with Scripps who died in 2006. Pizza 12:00 PM | Talk 12:30 PM