Author Emlen is the Professor you always hoped you would get for biology. With joyous discovery he writes of the evolution and development of animal weapons. When three factors are present, competition, economic defensibility and one-on-one battles, the arms race is on whether it is in dung beetles, flies, termites, shrimp, praying mantis’, birds, saber tooth cats, elk or sailing ships. Bigger seems always to be better; at least to the point where the cost for bigger teeth, horns, arms, claws or cannons becomes so prohibitive that the whole thing collapses on itself and evolution takes off in a different direction.

“Everything about weapons is expensive, from the resources pulled from the pool to permit their excessive growth, to the constant drain required to keep them, carry them, and use them in battle. Which is why weapon size is extra sensitive to the vagaries of life.”

The author supports his premises extensively by field work; with humorous abandon he harvests dung, studiously records the fight for such a limited and valuable resource, and details the arms races it engenders. The costs of huge antlers for the deer family, the huge costs of medieval armor or seventeenth century ships of the line all follow the same pattern. The examples are clear and the conclusions are supported by careful research. The author quotes other similar works and lists an extensive bibliography to look at the questions from other sources. The book is a scholarly, thoroughly enjoyable foray into evolutionary biology with a final warning about our own arms races.