Mass Extinction Spasm

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.

The study was co-authored by Wake and Vance Vredenburg, research associate at the Museum of Vertebrate Zoology at UC Berkeley and assistant professor of biology at San Francisco State University.

There is no consensus among the scientific community about when the current mass extinction started, Wake said.

It may have been 10,000 years ago, when humans first came from Asia to the Americas and hunted many of the large mammals to extinction.

It may have started after the Industrial Revolution, when the human population exploded. Or, we might be seeing the start of it right now, Wake said.

No matter what the start date, data show that extinction rates have dramatically increased over the last few decades, Wake said.

The global amphibian extinction is a particularly bleak example of this drastic decline, he said.

In 2004, researchers found that nearly one-third of amphibian species are threatened, and many of the non-threatened species are on in decline.

Source - NBC11