Genetic analysis of ancient skeletal remains has revealed that for the vast majority of human history, the enzyme lactase—which breaks down the sugar in milk—deactivated after infancy. However, approximately 10,000 years ago, a genetic mutation emerged that allowed lactase production to persist throughout adulthood. This mutation arose alongside the development of early dairy farming in Europe and Africa. In communities where cattle domestication became central to survival, individuals who could digest milk had a major nutritional advantage, especially during periods of crop failure. As a result, this genetic variation spread rapidly through these pastoralist populations. Today, adult lactose tolerance is highly concentrated in populations with ancestral ties to dairy farming, while it remains rare in regions where ancestral societies relied solely on agriculture or hunting.
Which of the following best expresses the central theme of the passage?
- AAdult lactose tolerance is a universal trait that developed before humans began domesticating animals.
- BThe mutation for lactase persistence first emerged around 10,000 years ago in Europe and Africa.
- Human genetic evolution has been directly influenced by cultural practices like dairy farming.Cevap
- DDietary habits and genetic traits have always played a critical role in the survival of human civilizations.