Thursday, July 09, 2009

Beginning to Think About the Medea Hypothesis

I'm reading The Medea Hypothesis by Dr Peter Ward. The basic premise is that life is toxic to life and will, eventually, kill itself off. I'm about 2/3s done and there have been a number of things that are bugging me. I'll do a post eventually, however, I went looking for some responses to the book...so far, only one major one. There was some criticism by fellow scientists there:

Lynn Margulis, a noted biologist at the University of Massachusetts,Amherst, who helped Lovelock shape and promote the Gaia concept,dismisses Ward's work as misguided, describing it as “pseudo-quantitation, a nice example of the fallacy of misplaced concreteness.”

J. David Archibald, a professor of biology and a vertebrate paleontologist at San Diego State University, said he was “underwhelmed” by the Medea idea. “I don't know that it tells us anything we didn't already know.”

Christopher Wills, a biologist at the University of California San Diego and co-author of “The Spark of Life,” a 2001 book on the origins of life on Earth, said it was too simplistic to say life causes mass extinctions. There are other, perhaps more compelling, factors, too.

“The dramatic changes in the Earth's climate have been accompanied by meteorite impacts and truly mind-boggling massive volcanic eruptions,” said Wills. “The Siberian eruptions that accompanied the great Permo-Triassic extinction 200 million years ago piled up layers of lava 10,000 feet thick over an area of 75,000 square miles. Life
didn't cause that.”

Wills' co-author, Jeffrey Bada, a marine chemist at the Scripps Institution of Oceanography, also found the hypothesis wanting, particularly its eventual doomsday scenario.

“Given the ability for life on Earth to seemingly adopt to slowly changing conditions, I find the hypothesis to be far-fetched. There are certainly bacteria, some of which are photosynthetic, that would survive (increased solar radiation). And there is convincing evidence that some bacteria live far below the surface of the Earth, so they would be survivors as well.

“Animals, including humans, would probably have a rough go, but given the billion-year time scale for this scenario, it is likely that other catastrophes – a large impact event, nuclear war – would do these life-forms in before the heating was severe.”


One of the criticisms I have of the book is that there is a paper by Franck et al (2006) that is heavily cited...yet does not appear anywhere in the bibliography. Given it's absolute importance to the central thesis of the book, it's absence is pretty glaring and embarrassing. Fix it, guys, eh?

I've been googling for the paper and coming up empty handed. It has to do with paleoatmospheric content. Again, Franck et al 2006. I'll dig through and see if I can narrow down the journal. If anyone has it, *grovel*.

2 comments:

Neil said...

Possibly, S. Franck, C. Bounama, and W. von Bloh 2006, "Causes and timing of future biosphere extinctions" Biogeosciences, 3, 85–92, 2006
www.biogeosciences.net/3/85/2006/

free .pdf here:

http://hal.archives-ouvertes.fr/docs/00/29/75/42/PDF/bg-3-85-2006.pdf

Will Baird said...

Thak you, Neil, that's it. A lot of the graphs in the book come straight from the paper.