Ryan, a former physician, describes the trajectory of research on animal metamorphosis over the last 200 years, from the work of Darwin through Sir Vincent Wigglesworth (the father of insect physiology), entomologist Carroll Williams, and the husband-and-wife team of Lynn Riddiford and James Truman. This train of research leads to contemporary marine biologist Don Williamson and his controversial theory that evolution occurs not just through mutation but also through hybridization, implying that larval and adult forms of many animals were once wildly different creatures whose genomes melded during trans-species hybridization. The book also makes note of the role of the internal politics of science, in which new ideas are not always welcomed. Ryan has written other books explaining current science research. Annotation ©2011 Book News, Inc., Portland, OR (booknews.com)