PRECONDITIONS FOR THE REVOLUTION
Especially at this point in our story, we must remember how culture and environment go hand in hand. Neither plants nor animals domesticate themselves; men domesticate them. Furthermore, men usually domesticate only those plants and animals which are useful. There is a good question here: What is cultural usefulness? But I shall side-step it to save time. Men cannot domesticate plants and animals that do not exist in the environment where the men live. Also, there are certainly some animals and probably some plants that resist domestication, although they might be useful.
This brings me back again to the point that both the level of culture and the natural condition of the environment—with the proper plants and animals in it—must have been ready before domestication could have happened. But this is precondition, not cause. Why did effective food-production happen first in the Near East? Why did it happen independently in the New World slightly later? Why also in the Far East? Why did it happen at all? Why are all human beings not still living as the Maglemosians did? These are the questions we still have to face.