The Pattern of Evolution

Rating:
Summary: A Wegenerian epic?
Review: Eldredge would have done better to end this book at the second paragraph: "Richard Dawkins must be right after all!" Unfortunately, after making this capitulation he then turns to a pejorative, labelling Dawkins and his [unnamed] colleagues as "UltraDarwinists". It is difficult to perceive how anyone can be 'beyond Darwin', but Eldredge returns continually to the phrase.

For a generation, Eldredge, in collaboration with Stephen J. Gould, has attempted to erode Darwin's 'natural selection' mechanism of evolution. Instead of gradual, incremental change, they urge evolution as progressing in fits and starts. The idea is indirectly supported by the imperfect sequence of the fossil record, a point Darwin conceded in Origin of Species. Eldredge uses the remainder of this book to explain why 'natural selection' should be replaced by 'punctuated equilibrium' - it follows the pattern of history. The pattern is that a traditional idea replaced by more innovative concepts. The key example here is the replacement of gradualism in geology replaced by the more determined action of continental drift. Eldredge wants to replace Darwin's form of 'gradualism' in evolution with a Wegenerian concept in biology, punctuated equilibrium. This will gain Eldredge [and, one assumes, Gould] a stature in the history of science equaling Wegener's.

Daniel C. Dennett's DARWIN'S DANGEROUS IDEA offers a penetrating analysis of the punctuation idea. Illustrating the fallacies of the thesis, failing to provide a scale for measuring rate of species change, for example, Dennett's critique should have swept away any vestige of support for the idea. The 'UltraDarwinists' use molecular genetics to reinforce Darwin's original concept. While earth's history has experienced episodes of rapid change [a 10 km bolide provides an earthshaking [sorry!] environmental pulse], such events are not the mechanism of evolution.

Eldredge's own example of the Cecropia tree, a continuing theme through this book, is a perfect example of why Dawkins is right and Eldredge wrong. Cecropia's forebears adapted to the impact of increasing hurricane frequency due to the closure of the Panamanian isthmus. Eldredge calls Cecropia's emission of dormant seed pods 'cheating'. Yet that's exactly what Dawkins calls adaptation to environment. How rapidly did Cecropia 'learn' this trick? Where did it learn it? Clearly, those trees whose genes contributed to seed dormancy survived to enhance the talent in later generations. Why Eldredge fails to examine that aspect is a mystery, since it is evolution's method.

Recommendations about this book don't come easy. The dispute over 'punctuated equilibria' has gone on too long. Readers should be aware of Eldredge's views [and cheap rhetoric], but learn why he's wrong. Read this book, but don't buy it. Rush over to the Dennett page and pick up Darwin's Dangerous Idea, a book that deserves shelf space in anyone's library.

Rating:
Summary: Excellent review of evolution and speciation
Review: Niles Elderidge picks up where he left off in "Reinventing Darwin" and "Fossils: The Evolution and Extinction of Species", and takes the reader on a tour of the history of evolution. I thoroughly enjoyed this book. He starts off with admitting he caught himself at one moment contemplating whether Richard Dawkins might actually have been correct in his "selfish gene" theory about evolution. "My God, Richard Dawkins must be right after all!" he exclaims on the first page. But soon he calms down, takes a deep breath, and looks at the larger picture. He argues (convincingly, in my opinion) that evolution does not occur all the time, and that in fact species are quite stable and will last for millions of years, until some sort of environmental event happens which wipes out not only species but entire ecosystems as well. Most of the time, if there's a local change in the environment, the species could simply move. But sometimes events happen which results in extinction (in fact, the species today represent less than 1% of all species that have ever existed). Evolution occurs from the survivors of extinction, radiating to fill in new niches. This is Darwinian evolution, but not quite the gradual improvement often taught by the "Ulta-Darwinists". I found this book a delight to read, and thought he did an excellent job of summarising the history of the attempts to unite evolution with modern genetics.

Rating:
Summary: New Theory from Ecology-Evolution Interplay
Review: This book is noteworthy for two reasons. Most importantly Eldredge attempts an important advance of his earlier work on punctuated equilibria in evolution with a new model that he calls a "bucket-sloshing" model where ecological stabilities and regular evolutionary genetic drift alternate like sloshing water in a bucket to ratchet evolution. Secondly, the introductory chapters of the book are presented not just as background but as commentary on a fundamental divide within science, namely a split between historical sciences (geology, paleontology) and functional science (e.g. physics). Historical scientists commonly pursue pattern as opposed to cause or mechanism such as the more dominant functional scientists. Hence the "pattern" of the title links the holistic implications in both the contribution of historical scientists and the contribution of changing ecologies from events such as extinctions to "environmental" pressures.

His tone is grand and plodding even avuncular through much of the book as befits the scope of a paleontologist of his stature, but with it he opens the way for more of us to keep up with him. This is definitely an accessible book. Yet do not miss the important gems of theory that he brings to the dialogue to evolve our understanding of evolution.