The book is a difficult read and is not appropriate for high school. Despite its soft, colorful cover and relatively small size, this book is clearly intended for graduate biology students during seminars in which they discuss how higher taxa are categorized.

The book is not casual, light reading. It required my full attention and rereading of nearly every paragraph. To emphasize this point, I used Readability-Score.com, an online readability analyzer, and randomly selected three 100-word passages. The Flesch-Kincaid Reading Ease, which ranges from 0 to 100 (with higher scores indicating more readable texts) scored the text at 21.7. Grade Level scoring, which typically aims for a reading level of 8 for public texts, averaged 14.7.

The first two chapters of this book deal with the nature of both organisms and higher taxa. Chapters 4–6 deal with paleontological, developmental, and ecological evidence of higher taxa. Chapter 7 examines invertebrate examples of higher-taxa categorization and chapter 8 discusses the vertebrate fossil record. The final chapter is a synthesis of the rest of the book and a conclusion about the general nature of higher taxa.

ELIZABETH COWLES teaches introductory biology, biochemistry, and entomology at Eastern Connecticut State University. She has taught at the undergraduate and graduate college levels for over 20 years. Her interests include insect toxicology, protein characterization, and astrobiology. Cowles holds degrees in biology and biochemistry from Cornell University and Michigan State University. Her address is Department of Biology, ECSU, 83 Windham St., Willimantic, CT 06226; e-mail: cowlese@easternct.edu.