GUNS, GERMS AND STEEL - Cloverport Independent Schools

162 • GUNS, GERMS, AND STEEL
tinents became an important reason why Eurasians, rather than peoples of
other continents, were the ones to end up with guns, germs, and steel.
How can we explain the concentration of the Ancient Fourteen in Eurasia?
One reason is simple. Eurasia has the largest number of big terrestrial
wild mammal species, whether or not ancestral to a domesticated species.
Let's define a "candidate for domestication" as any terrestrial herbivorous
or omnivorous mammal species (one not predominantly a carnivore)
weighing on the average over 100 pounds (45 kilograms). Table 9.2 shows
that Eurasia has the most candidates, 72 species, just as it has the most
species in many other plant and animal groups. That's because Eurasia is
the world's largest landmass, and it's also very diverse ecologically, with
habitats ranging from extensive tropical rain forests, through temperate
forests, deserts, and marshes, to equally extensive tundras. Sub-Saharan
Africa has fewer candidates, 51 species, just as it has fewer species in most
other plant and animal groups—because it's smaller and ecologically less
diverse than Eurasia. Africa has smaller areas of tropical rain forest than
does Southeast Asia, and no temperate habitats at all beyond latitude 37
degrees. As I discussed in Chapter 1, the Americas may formerly have had
almost as many candidates as Africa, but most of America's big wild mammals
(including its horses, most of its camels, and other species likely to
have been domesticated had they survived) became extinct about 13,000
years ago. Australia, the smallest and most isolated continent, has always
had far fewer species of big wild mammals than has Eurasia, Africa, or the
Americas. Just as in the Americas, in Australia all of those few candidates
TABLE 9.2 Mammalian Candidates for Domestication
A "candidate" is defined as a species of terrestrial, herbivorous or omnivorous, wild
mammal weighing on the average over 100 pounds.