Ancient Mass Extinctions Hint at Possible Ocean Future

[IDemo]

By Brandon Keim
January 11, 2011 5:06 pm

In sediment traces and fossil records from one of Earth’s most tumultuous periods, geologists have found a narrative linking mass extinctions with planetary biological and geological change.

After dramatic oceanic extinctions 250 million and 200 million years ago, the global carbon cycle turned chaotic. Earth’s biogeochemistry went boom and bust for millions of years thereafter, as if some regulating mechanism were lost — which is exactly what happened.

“People talk about saving biodiversity, and isn’t it good to have a variety of all these creatures. But the reason it matters is because ecosystem function is itself dependent on diversity in the face of normal environmental changes,” said geologist Jessica Whiteside of Brown University. “Lower diversity too much, and the system will lose its resiliency. It will become a slave to otherwise minor environmental changes.”

Whiteside specializes in reading the geological record of past extinctions, teasing from rocks and fossils the story of those times in Earth’s history when, for one reason or another, most forms of life ceased to exist.

http://www.wired.com/wiredscience/2011/01/biodiversity-carbon-cycle/