Did Microbes Cause The Earth's Most Devastating Mass Extinction?

A little over 250 million years ago, our planet experienced a mass extinction the likes of which have never been seen before or since. About 90% of all species were suddenly wiped out. And new study suggests it wasn't caused by an asteroid or super-volcano — but rather methane-spewing microbes. » 3/31/14 12:00pm 3/31/14 12:00pm