Latest Jack Sepkoski Stories
A detailed and extensive new analysis of the fossil records of marine animals over the past 542 million years has yielded a stunning surprise. Biodiversity appears to rise and fall in mysterious cycles of 62 million years for which science has no satisfactory explanation.
How the earth might recover from a mass extinction is as important as what might have caused the catastrophe in the first place. Penn State astrobiologists are looking at species immigration as one way for the Earth to recover its biodiversity.
- A person who stands up for something, as contrasted to a bystander who remains inactive.
- One of the upright handlebars on a traditional Inuit sled.