I've always been fascinated by how early North America was peopled and by what happened to all those really cool mammals - mammoths, mastodons, lions, and many far stranger species - that roamed the continent in prehistory. A new theory indicates that people may be innocent, or at least partly innocent, of the megafuna murder.
Numerous experts have supported the idea that all those megafauna were essentially hunted to extinction. I've always had a problem with the idea that this is the whole answer. Where, in historical times, is one example where we can say with certainty that indigenous people have hunted a an entire ecosystem of large, wide-ranging species to extinction? If all the largest animals in N. America were wiped out, along with their predators, why did Africa (until modern poaching) teem with elephants, rhinos, hippos, and the predators that fed on them? Humans had perhaps 2 million years to spread out and hunt in Africa, but only 13,000 years or so in N. America.
OK, enough editorial comment. Read for yourself why, according to a team led by James Kennett of the University of California, Santa Barbara, it looks likely a celestial body, most probably a comet, had a hand in the mass extinctions. I'm not sure from reading that that I would call it established fact, but it's certainly an intriguing possibility.
Thanks to Kris Winkler for this item.