An in-depth comparison of Eurasian and Native American societies in 1492 CE, when Columbus sailed to the New World, shows why Eurasians were able to come close to replacing Native Americans on the American continents. The biggest difference was in large domestic animal species, which were much more numerous in Eurasia. Plant domestication was less widespread in the Americas for a variety of reasons, as is discussed in earlier chapters. Even where agriculture was well-developed, the available plant species were less advantageous in the Americas. Corn, which is low in protein, was the main cereal crop. People had to plant their crops by hand rather than using animals to plow.

These differences in food production led to a difference in the number of infectious germs carried by the competing societies. The Europeans, who were carrying far more infectious diseases, infected and decimated Native American populations. Eurasia’s superior food production also gave Europeans the chance to develop superior technologies. By 1492 CE, all European societies made substantial use of metal tools, whereas only some Native American populations had managed to produce these tools. Stone and bone were still the primary tool materials on the American continent. Partly for this reason, Europe had far better military technology, so a few Europeans were able to defeat thousands of Native Americans at once. Europeans had more sources of power for machines, both from animals and from technologies developed as a result of food production. Eurasians had created wheeled machinery, ocean-going ships, and writing systems that were comparatively easy to learn. Eurasians and Native Americans also had different political situations. Eurasia had many large empires and relatively few remaining tribal systems. The Americas, in contrast, had just two large empires and many areas organized at the level of tribes and chiefdoms.

Diamond illustrates the differences in timing of the rise of food production and other developments in major Eurasian and Native American societies (see table 18.1 in the book). Food production appears to have been independently invented in the Americas four times, compared to twice in Eurasia, but in all cases it appeared much later in the Americas. Diamond argues that the Native Americans needed time to develop the tools appropriate to agriculture. Eurasians in the Fertile Crescent were already developing tools like stone sickles when the first settlers of the Americas arrived in Alaska, equipped with the tools and technology necessary for survival in Arctic regions. These tools would not have helped them develop agriculture, and they had little chance to begin inventing tools that would help until they moved into appropriate areas.

Compared to Eurasia, the Americas had a fragmented geography that prevented the spread of knowledge and technology. As stated earlier, this prevented crops and domesticated animals from spreading to new areas where they would grow well. It also resulted in less transfer of technology and knowledge. Diamond points to the greater linguistic diversity of Native American languages as evidence that Native American societies did not spread out and conquer large land areas, bringing their technology with them.

Diamond writes that Native Americans attempted to settle in Eurasia only one documented time in prehistory, when a group of Alaskan Inuit sailed and settled across the Bering Strait in Siberia. Europeans first tried to develop and conquer the Americas between 1000 and 1300 CE, when the Norse made several visits to Newfoundland and established a colony there. However, their shipping technology was not good enough to allow them to maintain support for that colony, and it failed.

Europe’s second attempt to colonize the Americas was successful. When Spain sent Columbus across the Atlantic, Spain was rich, populous, and well-equipped to support such a mission. The country succeeded in conquering large areas of the Americas, and several other European states sent explorers as well. In the Caribbean, South America, and Central America, Europeans used guns, germs, and steel together to conquer the people they encountered. In North America, germs did the vast majority of the work. Areas of the Americas that are suitable for farming crops are now largely used for growing Eurasian crops and animals. To varying degrees around the American continents, Native American populations have been replaced by or mixed with Eurasians.