Chapter 18, Blitzkrieg and Thanksgiving in the New World Summary and Analysis

About 11,000 years ago, humans first crossed the Bering Straights into Alaska and then spread south into North America. These peoples, referred to as the Clovis culture, used similar tools and their archaeological remains are widely distributed. Within about 1,000 years, they had colonized North and South America entirely in the single greatest range expansion of Homo sapiens ever to occur. In addition, roughly 11,000 years ago, 73 percent of North American and 80 percent of South American large animals went extinct. Then, very rapidly, the Clovis culture was quickly replaced by the Folsom culture, which specialized on hunting smaller animals and buffalo - the sole remaining abundant large mammal.

Although the reasons for the mass extinctions are somewhat debated, the most likely explanation is that they were hunted to extinction by...