<HTML>There is no "drifting" for 90,000 years.... During the Pleistocene, the environment was much cooler and more humid (with minor exceptions) than today. As a result, plant species flourished in abundance in the vast savannah grasslands that enveloped much of what is today the temperate regions of earth.
In addition to gathering the rich cornicopia of readily available natural foods, paleomegafauna (the large mammals like mastadon and mammoth) provided ample meat for the hunter-gatherer diet. Lastly, human populations were small, with most human groups living in bands of approximately 25-35 people. As a result, agriculture was unnecessary.
There were few mouths to feed and plenty of food to do it. Why bother with labor-intensive agriculture when a lazy day of picking plants garners the same result? (Hunter-gatherers were estimated to have a 3-4 hour work day; early farmers more than twice that.)
So the question is not it took so long to arrive at agriculture, but why they ever thought to do it at all. As Mikey's quotation above reflects, a complex series of factors brought agriculture into being. For my money, I think that climate change combined with increased population pressure led to cultivation.
Jason</HTML>
