Question

Why must young humans digest milk? Why does the lactase gene typically shut off after childhood? What does the evidence of the microevolution of lactose tolerance tell us about the evolutionary history of peoples who domesticated cattle?

Answer 1

Lactose intolerance is a common condition where the lactose in milk cannot be digested properly, causing symptoms like bloating and cramps. Humans have evolved the ability to digest milk due to a genetic mutation thousands of years ago, giving them an advantage. The domestication of cattle and the consumption of cow's milk played a significant role in human culture and history.

Step-by-step explanation:

Lactose intolerance is a common condition in which the lactose found in milk cannot be digested well in the small intestine, causing symptoms such as bloating, cramps, and nausea. Most adult mammals cannot drink milk because they lack the enzyme lactase, which metabolizes lactose. Humans, especially those of European descent, have evolved the ability to digest milk due to a genetic mutation that occurred thousands of years ago, providing an evolutionary advantage. The domestication of cattle and the consumption of cow's milk started during the agricultural age and continues to be a significant part of human cultures.