The Black Hole...

... is what Australian naturalist Tim Flannery calls the mouth of Paleolithic man, down which the megafauna may well have disappeared.

Matt just sent me this article about recent studies by Paleontologist Dale Guthrie (whose recent book The Nature of Paleolithic Art is one of the best I have read this year) that seems to contradict the Overkill Hypothesis-- its title is "Climate change, not Humans, Killed Large Beasts".

Were two of my heros, Professors Guthrie and Martin, in conflict?

Well, not really, as the article was about something a lot less specific than the deadliness of Paleolithic hunters.

"Dale Guthrie of the University of Alaska has added 600 radiocarbon-dated fossils to the established collection, and his examination reveals that mammoths and wild horses were in serious decline before humans arrived on the scene in Alaska and the Yukon Territory.

But the article goes on to state:

"David Steadman, a researcher at the University of Florida who believes humans drove the giant sloth to extinction, agrees that encroaching boreal forest may have been the end for large mammals in the North. But what about across the rest of the continent?

"It's a great piece of evidence—I don't doubt it; I trust his data," Steadman told LiveScience. "What happened in Alaska and the Yukon is swell, but why did these things die out in Texas and Mexico and Arizona and Florida?"

"Like many researchers in the field, Steadman attributes a combination of factors to the extinction of these beasts. But he believes humans, and not climate, played the leading role throughout the New World.

" "There are so many things going on, and to me it's illogical to think that warming up and getting rid of ice sheets at 40 degrees latitude is a bad thing for large mammals," Steadman said. "They went through 20 glacial cycles in the last million years, and got through every one except for the last one. It has a certain odor to it, and that odor is of humans." "

Then Matt sent me still another article. Its title? "Giant Creatures Wiped Out by Hunters, Not Climate ".