Researchers have used a detailed global dataset of foraminifera fossils to study shifts in marine community structures before mass extinctions, offering an early warning system for future biodiversity losses due to climate change. The study, led by Anshuman Swain and Adam Woodhouse, highlights the importance of tracking ecological change 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, thrived in the oceans. These tiny creatures form the base of the food chain. Fossils of these ancient organisms provide insight into potential shifts in global biodiversity associated with our warming climate.
Using a global high-resolution dataset of planktonic foraminifera fossils, among the richest biological archives available to science, researchers have found that large environmental stress events leading to mass extinctions are reliably preceded by subtle changes in biological community composition that act as an early warning signal of extinction .
Fossil planktonic foraminifera. 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 Organic and Evolutionary Biology and an affiliate of the Museum of Comparative Zoology. Swain, a trained physicist who applies networks to biological and paleontological data, teamed up with co-founder Adam Woodhouse. University of Bristol to explore the global community structure of ancient marine plankton, which could serve as an early warning system for future extinctions 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 led to changes in marine plankton communities over the past 15 million years. “Our work offers new insights into how biodiversity responds spatially to global climate change, particularly during intervals of global warmth that are relevant to future warming projections.”
Using historical data for future predictions
The researchers used the Triton database, developed by Woodhouse, to see how the composition of foraminiferal communities changed over millions of years—an order of magnitude longer than is typically studied at this scale. They focused on the early Eocene climatic optimum, the last major period of consistently high global temperatures since the time of the dinosaurs, which is analogous to worst-case global warming scenarios.
They found that before the pulse of extinction 34 million years ago, marine communities became highly specialized everywhere except the southern high latitudes, suggesting that these microplankton migrated en masse to higher latitudes and away from the tropics. This finding shows that community-scale changes such as those seen in these migration patterns are evident in the fossil record long before actual extinctions and biodiversity losses occur.
Therefore, scientists think it is important to focus on monitoring the structure of biological communities in order to predict future extinctions.
According to Swain, the results of the foraminifera studies open up possibilities for investigating other groups of organisms, including other marine animals, sharks and insects. Such studies may spark a revolution in an emerging field called paleoinformatics, or use large spatiotemporal databases of the fossil record to gain 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, 17 Apr 2024, Nature.
DOI: 10.1038/s41586-024-07337-9
The scientists’ study was made possible by the National Science Foundation’s long-term field study aboard the research vessel JOIDES Resolution, which has been conducting ocean drilling around the world for the past 55 years. The project is due to end this year.