Sir, do you honestly believe that between the dawn of agriculture and the modern period people had free time to think about philosophy and science? The literacy rate in Europe before the advent of the printing press was limited to monks who would hardly have been passing on a signficant amount of genetic material. The vast masses of humanity lived short, brutish, nasty lives until after the industrial revolution. Thinking was not a popular passtime in medieval Europe, far less than in the Muslim world. Intelligence just plain would not have been selected for ahead of disease resistance on a continent riddled with plague and smallpox for the better part of a millennium. A dolt with generations of exposure to the animals that carried the disease would have a better chance of survival than a genius who did not. As far as the diversity of genomes is concerned, what I meant to imply was the tawdriness of emphasizing ethnic genetic disparity. If you annihilated all races on earth except for one, you would still preserve nearly all human genetic diversity. The most recent common male ancestor of all living humans probably lived as few as 60,000 "fucking" years ago, after all.