In the Blink of an Eye.

ANDREW PARKER 

Evolution's Big Bang took place beginning 543 million years ago, in the Cambrian period. At that time, all the major animal phyla of today evolved into their distinctive forms. In recent times, the reason behind this transition has vexed geologists and naturalists alike. Parker, a zoologist at Oxford University, says that he has the answer in something he calls the "light switch theory." He suggests that the development of vision in primitive animals caused a vast evolutionary explosion--some animals having eyes forced all animals to adapt or die. In this compelling book, Parker outlines how he's come to this conclusion and bolsters his case through a comprehensive overview of the fossil record. He cites evidence that creatures of the Cambrian explosion began to show coloration, an obvious connection to vision, and builds a case for this physical feature then leading to development of defense mechanisms and hunting. Perseus Publng, 2003, 316 p., b&w photos/illus., hardcover, $24.95.