Mass Extinctions and Periodicity
First published: 1984
Brief summary
Classic paper on claimed mass-extinction periodicity.
Article
The study analysed the timing of major extinctions in the marine fossil record and reported an apparent periodic component. Using extinction-intensity data compiled for geological families, the authors identified a recurring interval of approximately 26 million years.
The analysis treated extinction peaks as a time series and tested whether their spacing differed from a random distribution. The reported signal included several well-known extinction episodes and was presented as statistically significant within the chronology available at the time.
The paper did not establish a physical mechanism for the proposed periodicity. It considered the possibility that an unknown biological, geological or astronomical process might produce repeated environmental stress at broadly regular intervals.
Later work has re-examined the claim using revised geological time scales, alternative extinction datasets and different statistical methods. The original paper remains historically important, but the existence, period and cause of any long-term extinction periodicity remain debated.
Source details and credits
- Source / publisher: PNAS
- Source type: Research article
- URL type: WWW
- Credits: PNAS
- URL: https://www.pnas.org/doi/10.1073/pnas.81.3.801