The Tangled Bank is a detailed, thorough look at the theory of evolution, from pre-Darwinian contributors to recent (2009) discoveries. It is written in layman's terms and flows well, yet the content is not oversimplified for scientists. It is a pleasant read, with many sidebars, diagrams, sketches, cladograms, graphs, and other visual aids on most pages and in full color. Interesting facts are scattered throughout the book, such as how scientists determine the diets of fossilized organisms, how the molecular clock of neutral mutations can determine the time elapsed since a split from common ancestors, the evolution of complex adaptations (venom before fangs, and probably before snakes), the development of feathers from genes that originally produced scales, and the evolution of the complex eye, to name a few examples. This text gives answers to the questions students ask —— either out of curiosity or because they are trying to debunk evolutionary theory. For those students who don't appreciate the in-our-lifetime evolution of bacterial traits, a vertebrate example (the lizards of Pod Mraru in the Adriatic Sea) demonstrates natural selection on an uninhabited island over just 33 years!

There are a few minor details that could have clarified certain ideas for laymen, such as a traditional Punnett square to help illustrate crosses more clearly, simplified definitions (a phenotype is defined here as ““a manifestation of a genotype,”” which isn't a very clear definition for the layman), and a better explanation of dominance//recessiveness, for example. But these are minor shortcomings, and only a problem for those unacquainted with basic biology. The majority of the text constitutes an interesting addendum to basic evolutionary theory in easy-to-follow descriptions. For example:

The difference between a smooth pea and a wrinkled pea is determined by a single gene that encodes a protein to help break down sugar……without [this gene], a pea can't break down sugar effectively, and so sugar levels go up. A sugary seed absorbs extra water as it develops……when the pea begins to dry out, it shrinks……forming wrinkles.

There is a whole chapter on sexual selection, which most high school texts mention briefly, if at all. Evolutionary medicine and the evolution of behavior get their own chapters as well. In addition to the glossary and index, there are 14 pages of referenced works —— a valuable resource in itself.

This book is a great reference text for instructors, both high school and university; it uses everyday concepts such as bowling, bowls of jelly beans, and investment funds to explain more complex evolutionary processes. These explanations, along with literally hundreds of examples illustrating evolution, as well as sidebars on why creationism/““intelligent design”” is not supported by science, what a theory is in science, and many other topics, should give instructors a great tool for presenting the facts of evolution in a very interesting, thorough, and nonconfrontational way. For students of evolution or scholars who want to know the specifics about particular evolutionary processes, this is an excellent read. The fact that it is understandable to beginners and fascinating to scientists makes this book truly unique and valuable.

ELIZABETH COWLES teaches freshman 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.