Gulliver was a Bad Biologist

Most of my reading is nonfiction, but recently I read Jonathan Swift’s Gulliver’s Travels. The story describes Englishman Lemuel Gulliver‘s journeys to exotic lands, including Lilliput inhabited by tiny people, and Brobdingnag where giants live. Swift was a delightful and funny writer, but Florence Moog claims Gulliver was a Bad Biologist (Scientific American, Volume 179, November 1948, Pages 52-55). The problem is scaling, which Russ Hobbie and I discuss in Chapter 2 of Intermediate Physics for Medicine and Biology. The properties of animals change as they get bigger or smaller; you can’t just scale people up or down and expect them to function correctly. As Moog writes “for a student of comparative biology Gulliver’s book may serve as an unpremeditated textbook on biological absurdities.”

Moog’s first example was the 60-foot tall Brobdingnagians. She notes that because their mass increases as the cube of their height, supporting their body would “necessitate a truly ponderous skeleton” (A point I’ve discussed before in this blog when contemplating elephants). The giants would need thick stubby legs and fat bones.

Moog then considers the six-inch-tall Lilliputians. “If the Brobdingnagians were too big to exist, the mouse-sized Lilliputians were too small to be human.” She explains that smaller animals have a higher specific metabolic rate (that is, rate per unit mass) than larger animals. “Gulliver … failed to realize that the creatures of his invention would have spent the larger part of their time stuffing themselves with food.”

Why was I reading Gulliver’s Travels? Blame Neil deGrasse Tyson. The Public Broadcasting System is sponsoring the Great American Read this summer, where we vote for our favorite of one hundred famous books. In their Launch Special, various celebrities select their personal favorite, and Tyson—one of the few scientists featured on the special—chose Gulliver. Apparently he hasn’t studied Chapter 2 of IPMB. Regular readers of this blog know that I am a fan of Isaac Asimov, and I have been voting for his Foundation Series twice a day (once using the Firefox browser, and once using Safari) all summer.

Maybe Tyson has a point. Moog concludes that “after all, we must not be too hard on Gulliver for failing to understand the biological conditions that made him a man—and an implausible liar. His talents … were in the psychological realm.” His satirical story provides great insight into human behavior.