Tag Archives: jurassic period

Mass Extinctions Reset the Long-Term Pace of Evolution

A new study indicates that mass extinctions affect the pace of evolution, not just in the immediate aftermath of catastrophe, but for millions of years to follow. The study’s authors, University of Chicago’s Andrew Z. Krug and David Jablonski, will publish their findings in the August issue of the journal Geology.

Scientists expected to see an evolutionary explosion immediately following a mass extinction, but Krug and Jablonski’s findings go far beyond that.

“There’s some general sense that the event happens, there’s some aftermath and then things return to normal,” said Krug, a research scientist in geophysical sciences at UChicago. But in reality, Krug said, “Things don’t return to what they were before. They operate at a different pace, sometimes more rapidly, other times more slowly. Evolutionary rates shift, and that shift is permanent until the next mass extinction.” (more…)

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Dinosaurs Not So Fierce After All, says U of T Researcher

A new species of dinosaur discovered in Arizona suggests dinosaurs did not spread throughout the world by overpowering other species but by taking advantage of a natural catastrophe that wiped out their competitors. (more…)

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