Lactose Intolerance

730 Words2 Pages

Lactose intolerance is an inherited condition as indicated by a recently distributed survey, as well as complied research that has been collected. The survey results had only a small fraction of people who were lactose intolerant, 10%. However, almost 50% of survey takers family members had intolerance toward lactose. This proves several people are not born with the lactose intolerance activated but eventually with age the trait will activate since it has been inherited. Also majority of the survey takers are North American or European and in high school. Ethnicity, culture and age all have a large impact on whether or not the lactase enzyme is being produce, specifically in mammals.
A selective advantage of not producing lactase as an adult is simply saving energy for the body to use elsewhere. Young children need dairy products which contain lactose because it helps their bodies grow by providing healthy nutrients like fats, proteins, vitamins and it also helps make their bones stronger. As children grow older in to young adults their bodies are less inclined to need the large amount of nutrients the dairy products provide. Since the body no longer feels the lactose is a helpful source, the body slowly decreases the amount of lactase enzymes being produced. Typically a young adult can still comfortably have a glass of milk but the body progressively decreases the amount of lactase enzymes being produced. These lactase enzymes are what break down lactose and simple sugars. Once the body can no longer do this, a person will struggle digesting dairy products. This is a selective advantage because it helps the body save energy, instead of wasting it on producing these lactase enzymes. The body does not need lactose anymore so other...

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...ultures. Mostly all other ethnicities had a lactose intolerance or had a family member with lactose intolerance. It would be interesting to see a global survey and compare the results.
Based on the survey conducted in Part A and the evidence collected, lactose intolerance is an inherited trait which has evolved through natural selection. Human bodies and other mammals realized lactose does not have any benefits after a certain age. Mammal’s bodies started to identify lactose as an unhelpful nutrient and started to decrease the amount of lactase enzymes being produced. Eventually mammals bodies began to save energy by producing very few lactase enzymes and using the energy on something more beneficial for the body. This occurred through natural selection because the mammal’s body realized not producing the lactase enzyme and saving energy is a selective advantage.

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