From Publishers Weekly
Oxford University zoologist Parker tackles one of biology's biggest mysteries in this nontechnical account. He provides a relatively simple explanation for the sudden explosion of life forms that defines the boundary between the pre-Cambrian and Cambrian eras approximately 543 million years ago: "The Cambrian explosion was triggered by the sudden evolution of vision" in simple organisms. In Parker's "Light Switch" theory, active predation became possible with the advent of vision, and prey species found themselves under extreme pressure to adapt in ways that would make them less likely to be spotted. New habitats opened as organisms were able to see their environment for the first time, and an enormous amount of specialization occurred as species differentiated. Parker claims that his theory is far more robust than previous attempts to explain the surge in diversity, even those most recently advanced by proponents of a snowball earth (the theory presented by Gabrielle Walker in Snowball Earth). In readable prose, Parker provides detailed information on the fossil record as well as a wealth of interesting material on the role light plays in environments and how vision operates across a host of species. Although at times his tangents are a bit distracting, Parker's book will bring his controversial ideas to the general public. Photos and line drawings.
Copyright 2003 Reed Business Information, Inc.
Copyright 2003 Reed Business Information, Inc.
Booklist
The cause of the sudden appearance of major life-forms 540 million years ago, known as the Cambrian explosion, has been paleontology's biggest mystery and, next to the disappearance of the dinosaurs, its most fascinating to onlookers outside the science. Within the discipline, a new solution to the enigma has been boldly advanced, offered here in popular form by its expositor. Oxford zoologist Parker proceeds methodically, explaining, for example, what a phylum is, a point crucial to his theory because, contrary to popular perception, most phyla existed before the Cambrian explosion, he maintains. He believes that explaining the explosion means explaining the evolutionary advantages of organisms' external appearances, as discussed in the aptly titled Wonderful Life (1989) by Stephen Jay Gould. Building on Gould, Parker also revisits the celebrated Burgess shale central to that book, emphasizing the evolution of the eye in terms of its ability to detect light. Something fundamental changed in the earthly intensity of light and then in prey-predator dynamics, avers Parker, whose clarity will thrill science fans, as will his revolutionary theory. Gilbert Taylor
Copyright © American Library Association. All rights reserved
Copyright © American Library Association. All rights reserved
