Book Review

From the WaPo's review of Extinction: How Life on Earth Nearly Ended 250 Million Years Ago.

The last time Earth experienced a mass extinction, some 65 million years ago, at the end of the Cretaceous period, there is little doubt about what happened. A humongous meteor slammed into the Yucatan Peninsula, incinerating everything around for thousands of miles.

Funny. Kid Various rememebers that when the Alvarezes brought up this theory 25 years ago, it was on the fringe of science. Now, apparently, it's an established fact.

Actually the extraterrestrial catastrophe is not wholly accepted as the cause of the extinction of the Dinosaurs. What is basically unarguable is that a large asteroid did crash into the earth about 65 million years ago, approximately concurrent with the mass extinctions at the end of the Cretaceous. But there are a lot of niggling questions. As Robert Bakker points out, the Dinosaurs, as a group of species had been in decline for some time (although they had gone through declines before and rebounded.) And the extinction was very picky. Very advanced and adaptable creatures such as the Dinosaurs were completely wiped out (save the Avetheropoda) but much more primitive and seemingly less adaptable creatures like the crocodilia survived. Although Kid Various goes with the idea that the asteroid impact had to have something to do with the extinction at the K-T boundary, he doesn't buy that it is, in Justice Robert's language, "settled law."

Funny how science advances.

That said, this sounds like an interesting book. The Permian extinction always gets short shrift vis a vis the Cretaceous extinction, but it was way more devastating. 70% of all land animals and 95% of marine life died out within a few million years and no one really knows why:

Over the years, a cottage industry of Permian speculators has pointed the finger at just about every conceivable culprit. The list of indicted suspects includes -- take a deep breath -- plate tectonics, volcanoes, glaciation, a meteor, a supernova, a massive methane burp from the depths of the sea, oxygen-deprived oceans, an overly complex global ecosystem that collapsed under its own weight and, most fantastic of all, a buildup of cancer-inducing dark matter in the Earth's core.

Kid Various is writing a paper putting forth the theory that it was a wave of mass suicide bombings by synapsid jihadists who considered diapsids to be heretics.

Hah, hah! Just kidding Islamists!
(please don't kill us...)