The Cambrian Explosion was one of the great mysteries of evolution. The sudden proliferation of life forms 550 million years ago baffled even Darwin, who, in The Origin of Species, admitted that such rapid diversification presented a valid argument against his theory. But now, a century and a half later, 34-year-old Oxford University researcher Andrew Parker advances a new explanation of the Cambrian Explosion so compelling that many prominent scientists have accepted its plausibility. Parker contends that it was the development of sight in animals that caused biology's Big Bang. His account of how he solved the problem of the origin of biodiversity unfolds with the excitement of a topnotch whodunit.
We do have a well-written book, containing much really interesting science and a good strong hypothesis that will surely stimulate others to praise, to criticize and try to refine or replace. That is to say much. — Michael Ruse
A brilliant and eminently readable evolutionary detective
tale...[Parker's] energy and intelligence are undeniable.
August 17, 2003
I don't think you can find a more reader-friendly introduction to
Parker makes a compelling case...It's a neat theory.
[Parker's] central argument certainly deserves careful attention,
especially as it aims to provide a unique and hitherto unrecognized
solution to one of evolution's most significant conundrums.
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, see Forecasts, Jan. 20). 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. (Apr.) Forecast: Book review editors might review this together with Snowball Earth, enhancing sales of each. Parker will also cross the pond for a six-city author tour. Copyright 2003 Cahners Business Information.
The refinement of what is known about the evolutionary process continues with the work of Parker, who began his direction of thinking with the discovery by scientists that there was an explosion of life at the beginning of the Cambrian era. "The Cambrian explosion... is the sudden acquisition, 543-538 million years ago, of hard external parts by all the animal phyla found today (except the sponges, comb jellies and cnidarians). It is the spontaneous transition from the prototype worm-shaped or soft-bodied form to complex characteristics within each phylum, and it happened in a blink of an eye on the geological time scale." Carefully and methodically, using examples from around the world but especially from the Burgess formations near the popular resort area at Banff in Canada, Parker builds his case that "Between 544 and 543 million years ago a revolution took place. During this one million year period, vision was born." In addition to the idea that the appearance of the eye triggered immense changes in life forms, he looks at the evolution of color and of the food web and predation. In addition, "another factoractive predationcan also be associated with the beginning of the Cambrian explosion." Aficionados of popular science with some background of training or reading will be intrigued by Parker's book. He acknowledges that he and other scientists (whose work he refers to liberally) do not have the final word, but they are following intriguing clues. In the school setting, a biology teacher could use this to increase interest in class. Parker works at being as nontechnical as possible while still getting his point across, but this book is pretty challenging for all but themost advanced teen readers. KLIATT Codes: ARecommended for advanced students and adults. 2003, Perseus, Basic Books, 316p. illus. index., Ages 17 to adult.
The Cambrian Explosion lasted 43 million years, a blink of an eye on the geological time scale, yet during that period all animal phyla evolved complex external forms. The cause of this unique event has baffled scientists since Darwin. Now, Parker, a world-renowned zoologist at Oxford University, has come up with the "Light Switch" theory: the Cambrian Explosion was caused by the evolution of sight. Using evidence from a variety of disciplines, including paleontology and modern physics, Parker provides an insightful glimpse into the mind of the scientist and demonstrates how scientists progress from an idea to a conclusion by considering, exploring, and refuting possible explanations. Unfortunately, this approach sometimes makes the narrative seem disjointed. There are some lovely drawings and diagrams, particularly of the fossils, which help illustrate Parker's theories; however, some require more explanation. In addition, some knowledge of biology and physics is needed in order to understand some of the more complex concepts. This thought-provoking work would be of most interest to academic libraries. (Index not seen.)-Catherine Jeanjean, Kansas State Univ. Lib., Manhattan Copyright 2003 Reed Business Information.