The Nemesis Affair - David M. Raup

David Raup was, along with Jack Sepkoski, one of the scientists who said the fossil record showed evidence of periodic extinctions every 26 million years. Which in turn helped prompt the whole search for a mechanism that could do that, which led to the notion of the Sun having a companion star which hurls comets at Earth when its orbit brings it nearby.

This book isn't so much about that. Raup is a paleontologist. Outside mentioning some people who are studying them, he leaves discussion of Nemesis, Planet X, or the Solar Systems oscillations through the galactic plane alone. He does discuss his and Sepkoski's work some, as well as other studies they did on related topics. Such as investigating whether reversals in the Earth's magnetic field could be mapped to a set pattern and correlated with mass extinctions. 

Raup is more focused on the nature of research in sciences. The peculiar ways in which scientists regard themselves and their pursuits, versus reality. The notion that they are objective and always ready to accept new theories with supporting evidence, when they can be just as entrenched and dogmatic as any religious figure. He talks about Darwin's friend Charles Lyell, and how his belief in gradualism crushed Cuvier's idea of catastrophism so utterly that for decades to even suggest significant changes in the earth were the result of massive, random actions would get you laughed out of a symposium. Or worse, ignored entirely.

Raup, like Muller, is open about how he is as guilty of this at times as anyone else. That when Walter Alvarez first proposed the idea of the iridium layers as significant, he was ready to dismiss the notion outright. Because it just seemed too ridiculous. He doesn't opine on the need to balance being receptive to new ideas with skepticism the way Muller did, however. He does discuss the curious role the press plays in the scientific world more than Muller. How scientists will sometimes regard it as a breach of conduct to discuss their research in newspapers, as that's glory chasing or unseemly. And that some journals will even refuse to publish an article if the authors do that. I assume because it could be seen as circumventing the peer review process that is meant to be followed prior to publishing.

I admit, I was hoping for more about the search for Nemesis than I got. There is a brief update at the end - the book was originally published in '85, then revised in '99 - that notes there still hasn't been a companion star found, or anything else that would explain periodic comet showers. But the look into the world of scientific research was fairly interesting, and Raup doesn't waste nearly as much time on pointless stuff as Muller did.

'The operative word here is "required". Clemens was not saying which explanation of the extinctions was most likely. Rather, he was saying we already have acceptable explanations without resort to meteorite impact. The practical effect is that a new idea requires a truly compelling case - intellectual overkill - to displace the incumbent.'