Re: What was there in the world 10,000 years ago?
Early humans were hunter-gatherers. Moving around to find food put a limit on the population size, as the naturally occurring food in an area would only support a certain population size.
Human population growth is attributed to the development of agriculture. Once humans started settling down in an area and began farming, they were able to produce larger amounts of food and ultimately the population grew in size.
A good example is the Aboriginals of Australia. They lived in Australia for roughly as long as humans lived in Europe, but never adopted an agricultural lifestyle, instead remaining hunter-gatherers for about 42,000 years to now.