Actually, we humans did not start "farming" until about 3000BC or so. And in the beginning, the farming was to gather animals so they did not have to hunt them all the time. Then grasses started to be grown to feed the animals if corralled and it was a while before grains and other carbs came into our diets becasue of our growing. When that happened, dental caries (cavities) became more common place. We did eat what fruit or other edibles were around, naturally, but meat was the mainstay of our diet.