" Let’s first consider how farming led to natural selection. It bears repeating that the very first farmers lived about 600 to 500 generations ago, and in most parts of the world, farming has been practiced for less than 300 generations. From an evolutionary perspective, this is not much time for lots of major evolutionary change, such as a new species evolving, but it is enough time for genes with strong effects on survival and reproduction to change their frequencies appreciably within populations. In fact, because farming so profoundly altered people’s diets, the pathogens they encountered, the work they did, and the number of children they could have, the origins of agriculture probably intensified selection on certain genes. "

― Daniel E. Lieberman , The Story of the Human Body: Evolution, Health, and Disease