LEILA FADEL, HOST:
Woolly mammoths are back in the news. While some scientists are dreaming of using advanced DNA sequencing to bring them back in real life, others are still debating what caused their disappearance 10,000 years ago. Jeff St. Clair of member station WKSU reports the debate provides new insights into their extinction.
(SOUNDBITE OF FLINT STRIKING)
JEFF ST CLAIR, BYLINE: Metin Eren often spends his afternoons knapping.
METIN EREN: It's a very soothing sound.
ST CLAIR: That's knapping with a K. He's a master flint knapper, fashioning stone tools in his experimental archaeology lab at Kent State University.
(SOUNDBITE OF FLINT STRIKING)
ST CLAIR: Eren is making replica Clovis points, the large, fearsome-looking blades first discovered in the 1920s near Clovis, N.M. They were the signature weapon of Paleo Indian hunters who spread across North America 13,000 years ago. They entered a landscape filled with mythical megafauna - woolly mammoths, mastodons, giant ground sloths and saber-toothed cats, all of which soon disappeared. Scientists have long debated whether hunters armed with Clovis tips caused these extinctions. Eren is using his flint knapping skills to find out.
(SOUNDBITE OF SPEAR THROWER CLATTERING)
ST CLAIR: Along with a mechanical spear thrower - it's basically a bow calibrated to replicate the speed of a thrown or thrusted spear - Eren uses lumps of clay to mimic mammoth meat. He's testing how far a Clovis point penetrates.
EREN: Three, two, one.
(SOUNDBITE OF SPEAR THROWER FIRING)
EREN: Oh, nice. So let's see how far it went into this block here - four inches. And that's going straight into flesh - no hide, no hair, nothing. I mean, if you're firing this at a actual mammoth, run as quick as you can because all you're going to do is annoy it.
ST CLAIR: In a recent study, Eren and his team fired different-sized Clovis points into the clay meat more than 200 times. They found that, at least in the lab, the large stone weapons are not very good at killing elephant-like creatures.
EREN: This evidence suggests that not only did we not cause the extinction of proboscideans. I don't think we could have.
ST CLAIR: Todd Surovell, an archaeologist at the University of Wyoming, isn't buying it. He spent the past seven years excavating a side along the Platte River where he believes ice age hunters speared a mammoth and set up camp to butcher it. He has no doubt that Clovis hunters routinely brought down elephants.
TODD SUROVELL: I tend to believe the archaeological evidence over this experimental evidence.
ST CLAIR: Not only that. He thinks these hunters were so adept that soon after arriving in North America, they killed off mammoths, mastodons and the like.
SUROVELL: Any time humans colonize a new environment, a massive wave of extinction follows.
ST CLAIR: It's called the overkill hypothesis - the idea that if Paleo Indians hadn't arrived here first, Europeans would have met mammoths in the New World. David Meltzer, an archaeologist at Southern Methodist University, says the overkill hypothesis coincided with the emerging environmental movement of the late 1960s.
DAVID MELTZER: Earth Day was created in 1970, so all that stuff is swirling around.
ST CLAIR: While the idea of ancient extinctions at the hands of humans served as a powerful warning, Meltzer says the dozen or so sites where mammoth bones and stone tools were found together are not a smoking gun.
MELTZER: That's one crime we didn't commit. We're guilty of God knows a million other things, but that's not one of them.
ST CLAIR: He points to massive climate change 15,000 years ago that set processes in motion, wiping out dozens of ice age species without human help. The debate over whether we killed them off is more than academic. It holds open the possibility that there may have been a time when humans weren't the most destructive force on the planet.
For NPR News, I'm Jeff St. Clair.
(SOUNDBITE OF MELODIUM'S "LACRYMAE") Transcript provided by NPR, Copyright NPR.
