Sarah Alvarez

I specialise in using the fossil remains of calcifying marine phytoplankton to explore ecosystem and evolutionary responses to past environmental change. My approach integrates geological evidence with insights of the modern ocean to better understand the implications of ongoing environmental change. I am particularly interested in understanding the significance of abrupt climate change for nannoplankton populations, and the factors that control the lnog-term evolution and biogeography of marine ecosystems.

My most recent research investigates the impact of the fifth mass extinction event 66m years ago on marine ecosystems. The arrival of a massive asteroid not only wiped out dinosaurs, but the vast majority of plankton - the critical foundation of the marine food chain. Using fossil records of their exoskeletons stretching back 220 million years, I reconstruct how plankton recovered their genetic diversity, size, and resilience in the millennia after the asteroid's impact.