Guns, Germs, and Steel: Chapter 9 Summary & Analysis

The chapter begins: “Domesticable animals are all alike; every undomesticable animal is undomesticable in its own way.” The sentence is a parody of the first sentence of Leo Tolstoy’s novel Anna Karenina, but Diamond is talking about the ways that we define success and failure in general. Call it the Anna Karenina principle: the definition of success tends to consist of a narrow, specific list of events, and failure is, in a word, “everything else.”

Animals do all sorts of things to help human beings. They provide wool to keep humans warm, and milk, meat, and eggs to nourish them. Dogs—that is, domesticated wolves—protect humans while they sleep. A domesticated animal is defined as an animal that is bred in captivity and over time, modified from its wild ancestors. And yet human beings domesticated a mere 14 species before the 20th century, of which the 5 most important by far are the cow, pig, goat, sheep, and horse.

The wild ancestors of domesticated animals can be found all over the world, but not equally—for example, in South America, there was only one large mammal, from which the alpaca and the llama are descended. Today there are no large, domesticated mammals in Africa—strange, considering how many people travel to Africa every year to see the large mammals like lions and elephants.

Yet another reason why Eurasian civilizations thrived is that they had an abundance of large domesticable mammals. Some basic qualifications for being domesticated: herbivorous or omnivorous, and weighing over 100 pounds. By such a definition, Eurasia had about 70 species that could have been domesticated. So why did Europeans succeed in domesticating the horse while Africans never domesticated the zebra?

One potential answer to Diamond’s own question is that culture made it easier for Europeans to interact with large wild mammals. But Diamond rejects such an answer. The hypothesis that culture barred Africans (and Australians, North Americans, etc.) from trying to domesticate wild animals is refuted by many pieces of evidence: 1) the fact that today, Africans readily adopt domesticated pets; 2) human beings’ universal fascination with animals; 3) the fact that Africans in modern times have continued to try to domesticate animals and failed. The final piece of evidence is especially strong: in modern times, there have been attempts to domesticate elk, zebras, bison, etc.—and almost all such attempts have failed. There must be a biological (in the animals, not the people) or environmental reason for Africans’ inability to domesticate large mammals.

Why only 14 domesticable species? We return to the Anna Karenina principle: there’s a short, specific list of qualities that make animals domesticable, and the vast majority of animals, even large mammals, don’t make the cut. Diamond goes over some of the qualities: 1) The animal cannot be carnivorous. To raise a carnivorous animal in captivity, you would have to track down smaller animals to feed it, and you’d have to feed those smaller animals, too. It’s more efficient to raise an herbivore or omnivore. 2) The animal must grow quickly. 3) The animal must be comfortable breeding in captivity. 4) The animal must not have a “nasty” disposition (as zebras do). 5) The animal must not have a tendency to panic in danger. 6) The animal must be used to herding (i.e., being controlled by a pack leader) in the wild. Put together, Diamond’s qualifications result in a small list of animals that are efficient to maintain in captivity (1, 2, 3), and easy for humans to control (4, 5, 6). There are only about 14 animals on the planet that meet such qualifications—the 14 animals that have been domesticated since ancient times.