AI study questions the timing of mass extinctions
An AI model trained on fossil records suggests three of Earth’s five recognized mass extinctions unfolded over millions of years, rather than as brief events…
Shuzhong Shen of Nanjing University used an AI model to re-examine the timing of Earth’s mass extinctions, finding that three of the recognized five unfolded over millions of years. The research, presented at the Geological Society of America’s meeting in Denver, sharpens the fossil timeline and complicates claims about living through sixth mass extinction.
The model, called OneStrata, analyzes fossil records at a reported resolution of 1,000 years. That finer timeline suggests the Late Devonian, end-Triassic and end-Cretaceous extinctions were not necessarily the sudden biological wipeouts often implied by the term “mass extinction.”
What OneStrata changes in the fossil record
Researchers commonly group fossils into geological intervals lasting millions of years. That approach makes large datasets easier to handle, but can blur biological changes that occur over shorter periods.
OneStrata uses a dataset called OneStratigraphy, which contains fossil information, to predict where millions of fossils from tens of thousands of sites belong in the geological record. The source describes its method as a transformer-based AI model that learns a shared probabilistic representation of geological time from fragmented stratigraphic observations.
It borrows an idea from language models. Rather than learning patterns in text, OneStrata works with fossil data and rock-layer observations to refine the placement of specimens in time.
The distinction matters. A broad time bin can make an extinction look abrupt even when biodiversity changed over a much longer stretch. A narrower timeline offers a different view of when species disappeared, though it cannot by itself show exactly how each ecological community changed.
There is a caveat. Shen noted that the analysis produces a biodiversity curve; species could have gone extinct while others quickly took their place. A changing overall curve therefore does not necessarily reveal the fate of every species or group.
Why the “Big Five” remain debated
The study builds on earlier work by Shen and colleagues. In 2020, a team of Chinese scientists used a supercomputer to reach a resolution of roughly 26,000 years. Their dataset included 11,000 marine fossils from more than 3,000 stratigraphic sections and traced diversity from the Cambrian to the Triassic, roughly 300 million years.
That earlier analysis found that the Late Devonian extinction, around 360 million years ago, unfolded gradually, with biodiversity declining over roughly 50 million years. In contrast, most life vanished during the End-Permian extinction in just 63,000 years.
Scientists do not agree on a single count of mass extinctions. Estimates range from three to as many as 20, according to New Scientist, as reported in the Yahoo account of the research. The familiar “Big Five” classification remains influential, but the new analysis challenges the assumption that each event was a short, sharply defined collapse.
The question reaches beyond ancient history. Many experts believe human activity is driving a sixth mass extinction, with anthropogenic climate change among the causes cited. The findings about ancient extinctions do not establish whether that present-day claim is correct; they do show how much the interpretation depends on the time scale used to read biodiversity change.
For the public, the distinction is significant: a long decline and a sudden collapse describe different patterns, even if both involve major losses. The new model offers a finer tool for studying those patterns, but its biodiversity curve cannot determine whether individual species vanished or were replaced by others.
Three of Earth’s five recognized mass extinctions, the analysis indicates, occurred over millions of years.
Source: yahoo.com
