World in 'Mass Extinction Spasm'

The NBC website, on 12th August 2008, has an article about how the earth is going through a new mass extinction. Its says,

Devastating declines of amphibian species around the world are a sign of a biodiversity disaster larger than just the deaths of frogs and salamanders, University of California, Berkeley scientists said Tuesday.

Researchers said substantial die-offs of amphibians and other plant and animal
species add up to a new mass extinction facing the planet, the scientists said in an online article this week in the journal Proceedings of the National Academy of Sciences.

"There's no question that we are in a mass extinction spasm right now," said David Wake, professor of integrative biology at UC Berkeley. "Amphibians have been around for about 250 million years. They made it through when the dinosaurs didn't. The fact that they're cutting out now should be a lesson for us."

New species arise and old species die off all the time, but sometimes the extinction numbers far outweigh the emergence of new species, scientists said.

Extreme cases of this are called mass extinction events. There have been only five in our planet's history, until now, scientists said.

The sixth mass extinction event, which Wake and others argue is happening currently, is different from the past events.

"My feeling is that behind all this lies the heavy hand of Homo sapiens," Wake said.