From Publishers Weekly
We all know Darwin's theory of evolution—natural selection favors some adaptations over others. But where do new adaptations come from? This problem baffled Darwin and is the main point of attack for opponents of evolution. Kirschner and Gerhart, professor at Harvard and UC-Berkeley, respectively, present their solution to the problem and take a few timely shots at the advocates of intelligent design. The key to understanding the development of complex structures, they say, is seeing that body parts as seemingly different as eyes and elbows are formed from the same basic molecular mechanisms. Thus, the authors propose, the metabolic building blocks of life functions can be rearranged and linked in novel ways with less chance of fatal variations than random mutation of DNA would allow. One piece of evidence they offer is the frequency of periods of "deep conservation" following evolutionary anatomical changes, where conventional theory would argue for continuous mutation and change. Though this seems like an elegantly simple solution, the underlying molecular biology is quite complicated. As for proponents of intelligent design, the authors say their theory turns some of their arguments on their head, converting "some of their favorite claims"—such as "irreducible complexity"—into arguments for evolution. (Oct. 19)
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*Starred Review* Since its publication a century and a half ago, Darwin's revolutionary theory of evolution has explained very well how natural selection winnows out the mutations most helpful in fitting a species to survive. Now two neo-Darwinian biologists have boldly extended the original paradigm by showing how the deep molecular biology of the cell actually fosters biological novelties when plants and animals need them most, not merely when random chance generates them. Surveying the latest genetic research, Kirschner and Gerhart adduce evidence that nature has preserved and compartmentalized those core innovations that maximize the adaptive flexibility of species from yeasts to humans. The dynamics of protein chemistry and the plasticity of embryonic cells combine to make creatures capable of assuming many different forms in a wide range of environments. The deepest and most stable processes in biology, thus, are those that prime species for further evolution. It is this biological priming for evolutionary change that Darwin's great rival Larmark was groping toward when he stumbled into error. And it is a theoretical realignment that acknowledges this "facilitated variation" that Darwin's disciples now need in order to fend off skeptics who have latched onto the implausibility of the old scientific orthodoxy premised on entirely random and gradual change in species. Remarkably lucid and comprehensive, this new theoretical synthesis will thus shift the grounds for debate in the controversy surrounding organic evolution. Bryce ChristensenCopyright © American Library Association. All rights reserved