The notion that we stopped evolving in the Paleolithic period simply isn’t true. Our teeth, jaws, and faces have gotten smaller, and our DNA has changed since the invention of agriculture. “ One striking piece of evidence is lactose tolerance. All humans digest mother’s milk as infants, but until cattle began being domesticated 10,000 years ago, weaned children no longer needed to digest milk. As a result, they stopped making the enzyme lactase, which breaks down the lactose into simple sugars. After humans began herding cattle, it became tremendously advantageous to digest milk, and lactose tolerance evolved independently among cattle herders in Europe, the Middle East, and Africa. Groups not dependent on cattle, such as the Chinese and Thai, the Pima Indians of the American Southwest, and the Bantu of West Africa, remain lactose intolerant.
Posted on: Sun, 30 Nov 2014 02:35:15 +0000
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