The most striking difference for a modern observer visiting -8000 would have been the scarcity of humans. People lived just about everywhere, from the farthest southern reaches of today's Chile to the Norse tundra, but they would have been hard to find, living in small and isolated bands. They had to be scattered, because the human animal is a carnivore by preference, and large carnivores surviving off the land require a large range - about 5,000 acres per person, in the case of carnivore Homo sapiens. Depending on local conditions, a band of just 25 hunter-gatherers could require more than a thousand square miles. The world of -8000 probably supported fewer than 4 million human beings, roughly the population of contemporary Kentucky.
-Charles Murray, Human Accomplishments, The Pursuit of Excellence in the Arts and Sciences, 800 B.C. to 1950