The cataclysmic extinctions that scoured Earth 200 million years ago might have been easier to trigger than expected, with potentially troubling contemporary implications.

Rather than 600,000 years of volcanic activity choking Earth’s atmosphere with carbon dioxide, just a few thousand years apparently sufficed to raise ocean temperatures so potent greenhouse gases trapped in seafloor mud came bubbling up.

Much of everything alive on Earth was soon wiped out. Another half-million years of vulcanism were just icing on the cake. The immediate question: What lessons, if any, can be drawn?

“Scientist...

On my laptop, I love Google+ like Winston loves Big Brother at the end of 1984. But on my phone, I don’t love it very much at all. And I’m not alone.

Shortly before Google+’s native app for iPhone was released on Tuesday, Ancestry.com founder and “Google+ unofficial statistician” Paul Allen projected that Google+’s skyrocketing growth was beginning to slow down. From a high of 2 million users per day, new signups had dropped to approximately three quarters of a million. In a follow-up comment, Allen guessed that that day’s release of the new mobile app might have “a slight positive impact” on g...