Think about it

We can measure time in Grandfathers. The distance between Grandfather and Grandchild is more or less roughly in the region of 50 years. In that scale, every interesting piece of Human development can fit into 150 Grandfathers, or 7,500 years.

That may seem like a large number - 300 generations is an awful long time. But if you think of it not in terms of generations, but people - then three hundred generations is absolutely nothing. Ignoring inbreeding, six hundred men and women stand between the invention of the iPhone 3G and the invention of the wheel. Perhaps not the whole of human history, but certainly the whole of MY human history - can easily hold a convention in our school hall.