Quote Originally Posted by Pannonian View Post
There is a time border in the form of the last Ice Age. If you go by the Diamond idea of how civilisation evolved, you'd need an ice age-free expanse across Eurasia, which AFAIK limits civilisation to the last 10,000 years or so. Give some time for agriculture to be discovered and developed, and the time frame fits the so called young earth numbers fairly reasonably.
There was no shortage of temperate, desert and tropical regions during the last Ice Age, all with their own ecosystems and evolutionary pressures, and all of which had been present in inhabited areas for hundreds of thousands of years (according to secular timeframes). Why then the sudden advent of civilization?