Using fossil evidence and modern water isotope measurements, the researchers’ goal is to understand the impact of extreme weather on early humans and the ecosystems on which they depended. Their data also could indicate how this sensitive, water-limited region will respond to climate change.
“Seasonality is a huge control on ecosystems. To understand paleo-landscapes, we need a better understanding of seasonality … in order to understand the conditions in which hominins, our ancient ancestors, evolved. We need high-resolution data focused on very small geologic time intervals,” said Beck. She is a co-principal investigator on the international study, which also includes collaborators from Ethiopia and the Netherlands.
“This project is related to Omo I and II fossil sites in southern Ethiopia, which were until recently the oldest Homo sapien fossils ever found.”
Beck said, “In the time represented by this project we go from living in a landscape that has multiple hominin living on it to one where Homo sapiens are the only ones. I want to know why. What enabled us to succeed where other species did not and how might those evolutionary advantages help us face a world that is becoming more extreme due to climate change?”
Beck has been working in East Africa on the Kenyan side of the Turkana Basin since 2010 and has participated in and led seven field seasons. She plans on bringing Hamilton students with her to southern Ethiopia. “There aren't a lot of geoscientists who are currently working on both sides of the Kenyan-Ethiopian border to holistically understand the Turkana Basin. The rainfall that sustains Lake Turkana comes from Ethiopia, so to understand this system, you have to transcend national political boundaries,” she said.
Beck described the site of her research — a lake that four million years ago was much larger than today. Now there are exposed rocks and sediments that house ostracods, sand grain-sized animals with calcium carbonate shells similar to those of bivalves. “I like to describe them as tiny shrimp-like critters inside a clam-like shell,” she said. The ostracod's shells do not decompose in an alkaline environment, making them ideal to study and evaluate climate change in smaller increments than has been done before.
Another objective of the grant is to bring a diverse population into STEM and specifically geoscience. The project will engage students on every level, from fieldwork to laboratory analysis and dissemination of results through conferences and publications. Beck and her co-PI will integrate U.S. students with those from Ethiopia through pre-fieldwork programming, collaborative fieldwork, and monthly Zoom group meetings to discuss analyses.
“We will be trying to quantify seasonality in East Africa during a key time when humans were migrating out of Africa. … And, connecting to our evolutionary past, we may show how we can respond in the future to climate scenarios that we have never seen before,” Beck said.