Extinction: Evolution and the End of Man (Hardcover)

Extinction is a book that draws together a great deal of empirical knowledge, and has an author who has thought long and hard about the issue during a lifetime of work in the field. At first I thought he was being overly pessimistic, but after reading the arguments presented, was won over by the veracity of his idea. Extinction is a well thought-out and incisive volume that should be read by anybody wanting an understanding of man's continuing - or in this case diminishing - place in the natural order.

But Boulter is not concerned here with cultural evolution. He is looking at the biological evolution of life on earth primarily through the fossil record and in particular through Fossil Record 2, a huge database that he has studied extensively. His theme, despite the book's title, is the diversity of life, the radiation of living groups, etc., and how an understanding of that diversity through an analysis of the fossil record can shed light on the evolutionary process. He analyzes the growth of life's diversity after the major catastrophic events in the earth's history and plots curves and comes to the conclusion that biodiversity is an example of exponential growth, and that the phenomenon of evolution is another example of a self-organized system (such as sand piles and the weather) driven by "power laws and pink noise." (p. 125)

Some of the interesting conclusions that Boulter comes to along the way to forecasting our extinction is that we probably did do in the Neanderthal. (He lists "selfishness" as one of our distinctive traits that the Neanderthal apparently didn't have enough of.) And yes, we wiped out the major fauna of North America within a thousand years or so of our arrival from across the Bering Strait. In fact, we are now living through a period of mass-extinctions, in particular of large mammals, and we are a major factor in those extinctions.

My problem with this book is that it is sometimes hard to follow Boulter's argument since he is not as direct as he might be. Then again it may be that I need to read more carefully! At any rate, the fact that biodiversity follows an exponential curve until it hits a catastrophic event is certainly one of his points. And that evolution is an example of a self-organizing system like that of a sand pile, and behaves in similar ways with large changes occurring less often than small changes, etc., is another. Do "groups of animal and plant Families follow clear rules in their origin, expansion, peak diversification and eventual extinction?" is a question he asks. (p. 124) His answer is yes, and the pattern can be traced. He adds that "extinctions are an essential stimulus to the evolutionary process." (p. 183)

The "new idea" (as he terms it, p. 182) that mass-extinctions come from "within" as a feature of self-organization does not seem convincing to me, although it is certainly intriguing and worthy of further study. He writes: "So modern man is kicking the sand pile and causing a severe avalanche that only started to crash down at the end of the last ice age...the fundamental cause continues: human aggression. The first phase was our killing other mammal species...then through human history our killing of one another."

But is it only a temporary irony that today there are more humans on this planet than ever before?

Aggressive we are. And we kill each other with an amazing abandonment, but have such actions led us toward extinction? The evidence is all to the contrary mainly because our reproductive abilities and our ability to exploit planetary resources outweigh our murderous tendencies. And besides the cause of at least some of the great mass extinctions of the past (huge meteorites) clearly came from without.

Boulter sees small animals inheriting the earth after we are gone. He notes (p. 193) that "insects and birds are still at the early stage of high diversification." What this means is that a group of animals that is continuing to diversify (continuing to grow in the number of species) will be safe from extinction until the diversification slows. This is a nice scientific understanding, but what it says to me is that a successful body and behavioral style (e.g., a Family or order or some other classification of organisms) is less likely to go extinct than a less successful one. One might say, QED.

He speculates (his terminology, page 176) that "our system is in free fall, out of control." We won't need "nuclear weapons," he posits, "or the inventions of science fiction writers." We are "doing very well...just with our use of fossil fuels." Exactly what he has in mind here is not entirely clear. Does he mean that we will pollute ourselves to death?

Elsewhere he writes about global warming, caused in part by our burning of fossil fuels, but advises that fluctuations in temperature are common, and that for much of the history of life on this planet it was hotter than it is now, and that, in fact, for 250 million years from before the P-Tr mass-extinctions until the Miocene there was no frost on earth. (p. 113) Furthermore, "between AD 900 and 1300 cattle were farmed in Greenland and the French tried to embargo English wine." (p. 122)

In short, this is not a text for the causal reader. It is dense, and in places, technical. But what Boulter has to say is worth the effort.