Final answer:
Extended lactose intolerance in humans demonstrates an evolutionary adaptation where the enzyme lactase is produced into adulthood, especially in European populations, aiding in the digestion of dairy and absorption of vitamin D, and showcasing the intersection of culture and genetics.
Step-by-step explanation:
The example of extended lactose intolerance in humans provides insight into human adaptation and the influence of diet on evolution. Lactose intolerance occurs when there is a deficiency or lack of the enzyme lactase, responsible for digesting lactose found in milk. While most mammals, including humans, typically lose the ability to produce lactase after weaning, some human populations, especially Europeans, have developed lactase persistence, allowing them to consume dairy throughout adulthood.
In regions where dairy farming and the consumption of milk products were integral to survival, such as in Europe, individuals with the genetic mutation for lactase persistence had an evolutionary advantage. This adaptation is thought to be connected to the ability to absorb vitamin D, as lactose-tolerant individuals in sun-scarce Northern Europe could obtain vital nutrients from dairy. Thus, lactose tolerance in humans is an example of how culture and biology can intertwine, influencing human genetics and driving evolutionary change.