The video explains how young mammals digest lactose using the enzyme lactase, which breaks down lactose into glucose and galactose. As humans age, lactase production declines, leading to lactose intolerance in many adults. The prevalence of lactose intolerance varies globally, with high rates in East Asia and lower rates in Scandinavia. Some lactose intolerant individuals can consume dairy without issues, possibly due to intestinal flora differences. Cultural adaptations, such as consuming fermented dairy products, help some lactose intolerant groups. Geographical factors, like climate, influence lactase persistence, with higher rates in regions favorable to cattle farming. Evolutionarily, lactase persistence developed as a selective advantage in dairy-consuming populations, particularly after the Neolithic Revolution.

What is the role of lactase in the digestion of lactose?

How does lactose intolerance affect individuals who lack the lactase enzyme?

What factors contribute to the variation in lactose intolerance among different populations?

Discuss the relationship between geographical factors and the prevalence of lactose intolerance.

Explain how the Neolithic Revolution influenced lactase persistence in certain populations.