Lecture: Switching from foraging to farming: Narrator: Listen to part of a lecture in a history class. Professor: So we've been talking about early civilizations, those that existed 7 to 8 thousands years ago and today I'd like to talk about the switch from foraging, or searching for whatever wild foods were available, to farming: intentionally cultivating crops. Now, the way that switch is frequently portrayed is that it was an improvement. The development of agriculture is usually portrayed as a good thing, but there are advantages to foraging. For one thing, it provides a better balance of nutrients and in particular, more protein ... at least compared to the diet of the early farmers. Foragers end up eating a greater mix of foods, both plants and animals, but the early farmers ... and to some extent this is still true today ... the early farmers concentrated on just a few crops, like rice and wheat. There was less variety and therefore a smaller range of nutrients and a lot more carbohydrates, so the quality of the diet wasn't as good and we have evidence of this. In Greece and Turkey, when comparing skeletons from forager communities to those of early farming communities we see that height declined when farming was adopted, quite dramatically I might add. Foragers were on average almost 15 centimeters taller than the early farmers. That's a lot. Furthermore, farming increased one's vulnerability to starvation. It was riskier to live off cultivated crops than to live off the wild, partly because it meant living off your plants. I mean farmers, even modern farmers, only cultivate about 20 different plants on average and even then they really focus on just three: wheat, rice, and maize. Modern foragers on the other hand depend on over 100 different plants; what with fruits, nuts, berries, roots, beans, and so on. So, if a few cultivated crops failed ... if the rice crops failed for example, the farmers were in trouble. Now, of course, wild plants could fail too, but foragers eat so many different plants they always have something to eat. Also, domesticated plants may be more prone to failure than wild plants. Don't forget, agricultural crops are the result of selective breeding. Farmers choose certain seeds, ones that have the qualities they want, refining the crop each harvest. So, if seeds from the plumpest potatoes or the whitest rice grains are chosen, the heartier strains, the ones that can resist insect attacks, or disease, or extremes of temperature, or moisture for example, may be eliminated because the farmer hasn't chosen seeds from plants with these characteristics. So, how did the switch from foraging to agriculture happen? Well, no one's really sure. Some speculate that during the final phase of the last ice age about 10 to 13,000 years ago, there was a shift in climate in a number of locations that led to the decrease of food you could forage for. The failure of wild harvests may have caused people in different parts of the world to plant some crops to make up for the shortage. There's evidence that the practice of cultivation existed at that time. For example, rice was cultivated in China as long as 10,000 years ago by people who were also still eating wild rice. By counting the proportions of wild rice and cultivated rice in plant fossil remains, archaeologists have determined that the switch to farming there was a slow one, taking about 4000 years. So, it didn't happen over night and there's evidence that other groups of people also cultivated some cereal crops, blending both foraging and farming for thousands of years, so putting people in little boxes and classifying them as either foragers or farmers, well, we don't do that anymore. Of course there were advantages to farming. Agriculture provided a greater quantity of food and when you have an increasing population, as was the case in ancient Southwestern Asia, that's a definite advantage. Also, with irrigation, crops could be planted in what was until then useless land. For example, wheat and barley didn't grow naturally on the land between the Tigris and Euphrates Rivers in ancient Mesopotamia, but once that land was irrigated all of it could become cultivated and hectare for hectare farming yielded more food than foraging. Farmers needed 20 times less land, 100 times less if they irrigated to feed the same number of people as foragers needed.