Interesting piece by Sid Perkins (sub. req.) in the Oct. 29 Science News on the discovery of fossil sloths in Haiti and Cuba 4,000 years ago. In the longstanding debate between climate change and human hunting in the extinction of the big mammals in the Americas 10,000 years ago, score one for the humans with this bit of evidence, presented by Ross D.E. MacPhee at the SVP meeting in Mesa, Ariz.

Such a recent demise practically absolves post–ice age global warming as the cause of die-offs among these mammals and could undermine climate change as the trigger for extinctions throughout the Western Hemisphere since the last ice age ended some 10,000 years ago.

The argument is straightforward – people traipsing all over the continent, big mammals die. No people out on the islands in the Caribbean, big mammals live. MacPhee and a bunch of other people published a paper along these lines over the summer in PNAS.