Researchers from the Massachusetts Institute of Technology (MIT), located in the United States, in collaboration with the University of Leicester, in the United Kingdom, have identified a pattern that may elucidate the five major mass extinctions recorded on Earth over the last 450 million years.
Common Mechanism of Extinctions
According to the study, published in the journal Physical Review Letters, the disappearance of species occurred because the environmental change happened at a rate exceeding their capacity for adaptation. Researchers from MIT and the University of Leicester formulated a model capable of explaining these five major extinctions under a single mechanism: environmental transformations too fast to allow species adaptation.
Analysis and Adaptation Limit
The comprehensive analysis of 27 occurrences over the last 450 million years demonstrated that all major extinctions coincided with moments when environmental modifications exceeded an 'adaptation limit' established by the model. The authors suggest that this discovery may help in understanding how biodiversity reacts to environmental changes and improve projections about the effects of current climate transformations.
Rate Versus Intensity of Changes
Although Earth's history contains drastic events that caused mass extinctions, such as the end of the dinosaurs, these, despite having distinct origins, may share a unifying principle. Instead of focusing only on the specific causes of each event, scientists created a mathematical model to correlate the speed of environmental variations with the time required for a population to evolve and adjust.
The findings point to the existence of this 'adaptation limit': below it, species manage to respond to changes and survive; above it, the risk of extinction increases drastically, regardless of the source of the environmental change.
Validation of the Scientific Model
To validate this theory, the team compared the model's projections with geological records of 27 episodes that occurred over the last 450 million years, all characterized by major modifications in the global carbon cycle. The investigation confirmed that the five major mass extinctions occurred precisely during periods when these changes surpassed the predicted adaptation limit.
The researchers explain that this understanding helps justify why very diverse events—such as intense volcanic eruptions, glaciation phases, or asteroid impacts—generated similar consequences for life on the planet. Thus, the proposed approach offers scientists a tool to better interpret the response of biodiversity to major global transformations and serves as a basis for predicting how ecosystems will react to contemporary environmental changes.