On Size and Life. Thomas McMahon, John Tyler Bonner. Scientific American Books.

On Size and Life Book Cover On Size and Life
Thomas McMahon, John Tyler Bonner
Scientific American Books
June 1, 1983

If elephants had legs proportioned like those of mice, they would be unable to stand without breaking them. Evolution produces organisms of varied sizes, and it is through evolution that the problem of adapting to that range of sizes is solved. The innumerable differences between the large and the small were first touched upon in the premier volume in the Scientific American Library, Powers of Ten, and they are further delineated in this book.

The authors, a biologist and an engineer, consider the implications of size and shape for organisms, beginning with a discussion of the role of size and natural selection. This, however, is only half the story. On Size and Life analyzes why size appears to impose specific restrictions on shape (and shape on size), why there are certain shapes that are physically impossible for large organisms, and how natural selection and physical constraints ally to eliminate nature’s less efficient shapes.

Using microscope, camera, and mathematical abstraction, the authors illuminate the beautiful regularities of nature, bringing unity to the great diversity of shapes found on earth. These discussions lead to a clearer understanding of why there are flying squirrels but no flying horses, why ants can lift 50 times their weight but humans struggle to lift things that weigh no more than we do, and why the smallest mammals and the smallest birds weigh about the same.

Absorbing and accessible, this exquisitely illustrated book imparts a fuller understanding of the intricacies of size and proportion.

Thomas A. McMahon is Gordon McKay Professor of Applied Mechanics at Harvard University. He is the author of many articles on dimensional analysis in nature and on animal mechanics. John Tyler Bonner is professor of biology at Princeton University and a fellow of the National Academy of Arts and Sciences. He is the author of several books, including Cells and Societies, Size and Cycle, and The Evolution of Culture in Animals.