On page 22 Dr. Sharon Moalem asserts that, “What doesn't kill us, makes us stronger.”
Moalem examines the various factors our body responds to through many different stimuli by creating ‘trade offs’ in order to meet the needs of our body’s demands. It is essential for our body to work with its environment to give us the greatest possibility of surviving and reproducing. This relates to Big Idea 4: Biological systems interact, and these systems and their interactions possess complex properties. Moalem talks about the effects of environmental factors on the production of essential vitamins such as Vitamin D and Folic Acid. Our body creates Vitamin D by breaking down cholesterol with the help of the sun’s UVB rays. Vitamin D is essential in creating strong bones especially during growth in children and is also linked to a healthy heart, nervous system, and immune system. On page 50, Moalem informs us that Vitamin D deficiencies can lead to cancers, diabetes, and even mental illness. Another vitamin, Folic Acid, is also essential to maintaining proper health. Folic acid helps the body replicate DNA when cells divide, therefore also promoting growth. On page 52, Moalem describes the dangers of Folic acid deficiencies which includes birth defects for children whose mothers lacked Folic acid during pregnancy.
There is one major problem. These essential vitamins are not just related in their function, but producing one also destroys the other. Folic Acid stores are protected by the skin and Vitamin D is manufactured in the skin. While UVB rays help manufacture Vitamin D, it effectively destroys Folic Acid. Essentially, in order to make Vitamin D we give up our stores of Folic Acid, yet both are necessary to our body’s growth.
This type of ‘trade off’ leads us to be susceptible to many diseases mostly in part due to our environment, in this case the sun. Do these ‘ trade offs’ make us or break us and how do they contribute to our overall health today? Since our bodies are able to find a proper balance of vitamins, most individuals do not develop Vitamin D or Folic Acid deficiencies. What adaptations or mutations allow our bodies to achieve this balance? Is it possible to make this balance more stable or efficient?
Going back to Moalem’s assertion that, “What doesn't kill us, makes us stronger.” In the end, is this true based on the limitations of our bodies? Explain.
(Ted Nowak, tnowak4@students.d125.org)
This comment has been removed by the author.
ReplyDeleteThese trade-offs essentially benefit us in the long run because the sun is our main source of Vitamin D. Vitamin D is important to our health because it is essential to our immune response. In fact, some scientists think that the reason why we get sick more often during the winter is because we stay indoors too much. If we stay indoors, then we get less sun exposure and less vitamin D, which will have a negative effect on our immune response. On page 51, Moalem states that less sunlight can result from being indoors in wintertime, but also from using sunblock. Without the sun, our cholesterol level would be higher because the sun converts cholesterol. Without the sun, we would be deficient in vitamin D and our immune system would not be as strong.
ReplyDeletehttp://www.sciencedaily.com/releases/2013/03/130320212824.htm
An adaptation that our body could have to achieve a balance in creating vitamin D and destroying folic acid is sunburn. If we stay out in the sun for too long, a lot of cholesterol is converted into vitamin D, but a lot of folic acid is also being destroyed. Sunburn prevents us from staying out for too long and prevents too much folic acid from being destroyed. A way to make this balance more stable is that we can take vitamin D supplements, so that we do not need the sun’s help to make it. If we are not in the sun, then our folic acid is safe.
“What doesn’t kill us, makes us stronger” is true in a biology context. It relates to Big Idea 1: The process of evolution drives the diversity of life. The “what doesn’t kill us” portion is the selection pressure. If a population has variation, and a specific variation gives an individual a higher chance to survive and reproduce, then over a long period of time the variation will become more prevalent in the population. They will have become better adapted and “stronger” to their environment.