Did an Exploding Comet Doom Early Americans?

New Scientist outlines a new theory on the demise of the Clovis people in the southwest US over 10,000 years ago. A group of 25 researchers speculates that a comet exploded over ice-covered Canada 12,900 years ago and triggered a firestorm across North America that not only wiped out the Clovis people but also forced a number of large land mammals into extinciton and kicked off the Younger Dryas climate change. However, geologists are pretty conservative folks, according to the article, and some of them are not buying it.

Comments

What about the firestorm?

[Podcaster]

a comet exploded over ice-covered Canada 12,900 years ago and triggered a firestorm across North America

According to TFA, the firestorm seems to be the most controversial part of their claims. All the dissenting voices in the article made mention of it.

According to the abstracts of the research, it looks like the strongest evidence of a trans-american firestorm is "... a carbon-rich black layer commonly referred to as a black mat, with a basal age of approximately 12.9 ka, ... identified at over 50 sites across North America"

-P

Geologists are indeed conservative.

[jd]

Just finished reading "The Map That Changed The World", the story of the discovery of plate tectonics. The reaction from the community was apparently not healthy skepticism but hostility bordering on fanaticism.

Re:Geologists are indeed conservative.

[gEvil (beta)]

I was going to make the same comment, but you beat me to it. I have a degree in Geology, and I remember my Historical Geology teacher telling us about how when he was in school nearly all of his professors ridiculed the idea of plate tectonics. However (according to him), he dismissed them as fools since the theory seemed to fit in so nicely with the available evidence. Just goes to show that the most important thing you can learn in school is to evaluate the data yourself.

Re:Geologists are indeed conservative.

[Temkin]

While I was wrapping up my Geology degree in the early 90's, I actually came across a old geezer with tenure at a symposium that kept rambling about granitizing fluids. Thankfully, he wasn't a prof at my school.

It's been said that any major change in the fundamental theories of a field will not be accepted until the old guard dies off. Plate tectonics was one such shift. I figure if we're wrong about global warming, we won't be able to admit it until 2045 or so...

Problem

[KwKSilver]

Clovis peoples did not "go extinct." They spread put across the Americas and developed in to more locally adapted cultures. The Folsom point is a fairly obvious derivative of the Clovis point see here. The Folsom point supplanted Clovis on the Lower Great Plains. From Missouri to the Atlantic coast the Dalton point is considered a direct outgrowth of Clovis, and on the western Gulf Coast, the San Patrice point seems to have filled the same role as the successor to Clovis. Aside from that, there is a lot of regional variation in Clovis itself prior to the emergence of Folsom, San Patrice etc.

The Pleistocene megafauna did go extinct, but the causes of that have been argued back and forth since I was a student in the 1970s, and with no end in sight. Some have blamed Clovis and closely related groups in the Americas, and refer to these extinctions as the result of a Clovis "blitzkrieg." However, there's also evidence to suggest that some were headed down the drain before humans reached the Americas. Late Pleistocene environments were drastically different from today. The southwest was fairly moist, not a desert at all. The southeast was considerably drier than now and had fine-grained, micro-environments quite unlike anything seen today. All of those environments changed drastically, and the intricately intermingled mico-ecologies of the southeast disappeared, and any fauna dependent on that was toast (my 2 cents, there).