Frogs and other amphibians lived through several mass
extinctions on Earth over the past 250 million years, surviving
the dinosaur wipeout and the most recent Ice Age. But now, say
scientists this week in the Proceedings of the National Academy
of Sciences, all that is changing. Amphibians are going extinct
in such huge numbers that we've entered nothing short of a new
mass extinction event. It's the sixth such event in known Earth
history. At least one-third of amphibian species are threatened
with extinction right now, and even non-threatened species are
suffering catastrophic declines in population. Most likely, the
causes are global warming and the shrinking habitats where
amphibians live. But what merits calling this a "mass
extinction"? The researchers explain in a release from UC
Berkeley: "There's no question that we are in a mass extinction
spasm right now," said David Wake, professor of integrative
biology at UC Berkeley . . . New species arise and old species
die off all the time, but sometimes the