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Reduced strength and increased variability of extinction selectivity during mass extinctions
Pedro M Monarrez1, Noel A Heim2, Jonathan L Payne1
1Department of Earth and Planetary Sciences, Stanford University, Stanford, CA 94305, USA.
Royal Society Open Science
|September 29, 2023
Summary
Marine animals with narrow geographical ranges face higher extinction risks. This effect lessens during mass extinctions, where body size becomes a more variable predictor of survival.
Area of Science:
- Paleontology
- Marine Biology
- Evolutionary Biology
Background:
- Geographical range and body size are key traits linked to extinction risk in marine fauna.
- Systematic comparisons of these traits' effects on extinction, particularly during background and mass extinction periods, are lacking.
Purpose of the Study:
- To investigate and compare the extinction selectivity of geographical range and body size in marine animals.
- To analyze these effects across different geological time scales, including background intervals and mass extinctions.
Main Methods:
- Utilized capture-mark-recapture models to assess extinction risk.
- Analyzed genera from five classes of benthic marine animals throughout the Phanerozoic Eon.
- Compared the influence of geographical range and body size on extinction probability.
Main Results:
- During background extinction periods, narrow geographical range was a strong predictor of higher extinction probability, while smaller body size had a weaker association.
- During mass extinctions, the link between geographical range and extinction probability decreased significantly across all classes, disappearing in some.
- The relationship between body size and extinction probability during mass extinctions showed variable strength and direction among different marine animal classes.
Conclusions:
- Geographical range is a consistently stronger predictor of survival than body size during normal background extinction intervals.
- Mass extinctions appear to alter extinction drivers, diminishing the role of geographical range and introducing variable effects of body size.
- These findings suggest a fundamental shift in extinction dynamics during global catastrophic events compared to background periods.
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