Researchers have used a detailed global dataset of foraminifera fossils to study shifts in marine community structures before mass extinctions, providing an early warning system for future biodiversity losses due to climate change. Led by Anshuman Swain and Adam Woodhouse, the study highlights the importance of monitoring ecological changes to predict future extinctions, potentially shaping the field of paleoinformatics.
A study using foraminifera fossils suggests that shifts in marine community structures can predict future extinctions, highlighting the role of historical data in predicting the impacts of climate change on biodiversity.
For hundreds of millions of years, single-celled organisms known as foraminifera, which are microscopic and have a hard shell, have thrived in the oceans. These little creatures form the base of the food chain. The fossils of these ancient organisms provide insight into possible shifts in global biodiversity linked to our warming climate.
Using a global high-resolution dataset of planktonic foraminifera fossils that are among the richest biological archives available to science, researchers have found that major environmental stress events leading to mass extinctions are reliably preceded by subtle changes in the way a biological community is composed. an early warning signal before extinction.
Planktonic foraminifera fossils. Credit: Tracy Aze / University of Leeds
The results are in Nature, co-led by Anshuman Swain, a Junior Fellow in the Harvard Society of Fellows, a researcher in the Department of Organismic and Evolutionary Biology, and an affiliate of the Museum of Comparative Zoology. A physicist by training who applies networks to biological and paleontological data, Swain worked with co-first author Adam Woodhouse on the University of Bristol to investigate the global community structure of ancient marine plankton, which could serve as an early warning system for the future extinction of ocean life.
“Can we use the past to understand what might happen in the future, in the context of global change?” said Swain, who previously co-authored a study on the formation of polar ice caps that caused changes in marine plankton communities over the past 15 million years. “Our work provides new insight into how biodiversity responds spatially to global climate changes, especially during periods of global warming, which are relevant for future warming projections.”
Leverage historical data for future predictions
The researchers used the Triton database, developed by Woodhouse, to determine how the composition of foraminifera communities changed over millions of years – orders of magnitude longer time frames than typically studied at this scale. They focused on the Early Eocene Climatic Optimum, the last major period of sustained high temperatures on Earth since the dinosaurs, analogous to the worst-case scenarios of global warming.
They found that, before an extinction pulse 34 million years ago, marine communities became highly specialized everywhere except the southern high latitudes, implying that these microplankton migrated en masse to higher latitudes and away from the tropics. This finding indicates that community-level changes, such as those in these migration patterns, are visible in the fossil record long before actual extinctions and biodiversity losses occur.
The researchers therefore believe it is important to emphasize monitoring the structure of biological communities to predict future extinctions.
According to Swain, the results of the foraminifera studies open up opportunities for research into other groups of organisms, including other marine life, sharks and insects. Such studies could revolutionize an emerging field called paleoinformatics, or use large spatially-temporally resolved databases of fossil data to glean new insights into Earth’s future.
Reference: “Biogeographic Response of Marine Plankton to Cenozoic Environmental Change” by Anshuman Swain, Adam Woodhouse, William F. Fagan, Andrew J. Fraass and Christopher M. Lowery, April 17, 2024, Nature.
DOI: 10.1038/s41586-024-07337-9
The researchers’ study was made possible by a long-term National Science Foundation field study aboard the JOIDES Resolution research vessel, which has been conducting ocean drilling around the world for the past 55 years. The project ends this year.