Extinction, both historic and projected, is the theme of this month's review. The book in question is The Miner's Canary by Niles Eldredge, 1991, Prentice Hall. This 6*9 229 page book lists for $20.00 in hard cover. The book is subtitled Unraveling the Mysteries of Extinction. You may recognize Niles Eldredge as co-author, along with Stephen Jay Gould, of the evolutionary theory of Punctuated Equilibrium. He is also Curator, Department of Invertebrates, at the American Museum of Natural History.
I tend to buy on impulse at times, this being one of those times. I looked no further than the name of the well known author, the subtitle, and the picture of a mounted baby hadrosaur skeleton on the dust jacket before rushing to the checkout lest someone else wrestle it from my hands. Had I read the dedication, which in part reads, "And for all who seek to mitigate the impact of Homo sapiens on the ecosystems of our planet", I may have looked at it more thoroughly before buying. Don't get me wrong here, I'm as interested in the world's ecosystems as the next guy, it's just not the topic I spend my book money on.
The first three chapters are spent rehashing what we hear almost daily on the news - the world's ecosystems are collapsing around us - third world countries are destroying habitat for creatures yet undescribed by science - remember the Great Auk, the passenger pigeon - remember the Dinosaurs! As you can tell, I didn't much care for these early chapters; in my opinion, they were written as if the intended reader had been living on the moon for the past twenty years with no communications with earth. For my taste there was far too much repetition of information already well known to the readership or previously presented within the book itself. Unfortunately, this pattern continues throughout.
The next four chapters redeemed the entire book for me. These chapters dealt with the facts surrounding the major extinction events through earth history. Eldredge uses these to reveal a common thread in mass extinctions which he later applies to the present time. The most prominent paleontologists dealing with the causes of extinction are referred to quite often in these sections; most noted are David Raup, Steven Stanley, and Jack Sepkoski.
The mass extinction most interesting to us at the end of the Ordovician, caused by glaciation and global cooling, was discussed. Even Dayton, Ohio was mentioned here (sorry Cincinnati) to contrast the great diversity of life during the upper Ordovician (at Madison, Indiana) with the lack of same in the early Silurian (around Dayton). Waldron, Indiana was used to illustrate how the diversity of life had rebounded by mid- Silurian times.
Each mass extinction was described and analyzed in depth for cause and effect. Much information is presented showing that in most cases, a decline in numbers of species was already well under way before the mass extinction. Eldredge presents all sides of the extinction debate and draws and presents his own conclusions.
The Cretaceous - Tertiary extinction drew extensive coverage. The iridium anomaly at the K-T boundary layer is well presented along with the impact theory. It is interesting to note that, at least to the date of publication, no other mass extinction event has shown an iridium peak. The bolide impact is reported to be the coup de grāce to an already declining diversity.
The next to last chapter dealt with the evolution of man and his effects on extinction of other species. Extinction of early homonids is dealt with along the same lines as any other animal extinction. We are indeed animals. My favorite, put 'em in their place, quote from the book is, "If people have stopped short of declaring themselves gods, they have not been shy in thinking of themselves as cast in the image of God. Such, of course, can be an ennobling image, but it also represents a flat denial that we are of nature. The Judeo-Christian tradition exhorts us to seek dominion over nature. We have forgotten who we are."
Also in this penultimate chapter [that's for Richard Davis who taught us that the accent is on the antepenultimate syllable] , the extinction of all large bodied fauna during the Pleistocene is discussed. Included, of course, is the potential effect that early man had towards this non-mass extinction.
The final chapter summarizes the author's opinions based upon the analysis presented throughout the book. He gives his views on the impact of modern man as an agent of extinction, the worth in saving even one species, and the effect of habitat destruction. I liked the way Eldredge pointed out that industrialized nations such as ours are quick to point fingers at the third world for mass habitat destruction, and are just as quick to pass over the fact the we have been doing the same thing for the past 2000 years.
In summary, if you're into environmental issues, you should enjoy The Miner's Canary as it uses paleontologic data to support modern ecological thinking. If you're more inclined to read paleo only type works, you may want to get this from the library and check out chapters four through seven; these do provide good summaries to current analyses of past mass extinction events.