Diamond’s thesis in Guns, Germs and Steel is that geography played a deciding role in the rise of civilization and the spread of technologies like agriculture, written language, and the use of metals. Australia, isolated from the rest of the world, is a case in point. Diamond points out that Australia is “by far the driest, smallest, flattest, most infertile, climatically most unpredictable, and biologically most impoverished continent.” As a result, Australia was never able to support the population densities needed to develop those technologies. Diamond compares Australia to its neighbor, New Guinea. New Guinea, although only one-tenth the size of Australia, is much wetter, has far richer soil, and a wider range of climates. For this reason, people in New Guinea were able to domesticate local crops, develop and use pottery, and invent technologies like the bow and arrow.