Survival of the Sickest part 1

What did you think about the reading?

The novel “Survival of the Sickest,” by Dr. Sharon Moalem, is one of the most interesting books that i have read in years. With his unique style of writing, and new and obscure ideas, Dr. Moalem captures readers and convinces them of the proof of his, and other’s, theories. I adore his style of writing because he makes it seem as though he is speaking directly to you, and he relates the theories to the reader’s life. I was immersed in the reading from the very beginning, as Dr. Moalem attempted to explain the reason for genetic diseases and disorders to exist in our gene pool, a question that I’ve had since I was younger. The topics he touches on in the start of the novel are intriguing, and you just can’t stop reading.

What did you learn?

Dr. Moalem starts off the novel talking about a genetic disease called hemochromatosis. Hemochromatosis causes iron to build up in a person’s blood overtime, and eventually, the amount of iron can reach dangerous levels. When a person gets iron overload, their organs can be damaged, like how the author’s grandfather developed Alzheimer’s because of the disease. This disease seems terrible, and people would think it should have been eliminated from the gene pool as soon as it appeared; yet it wasn’t, and Dr. Moalem explains his theory why. The gene for hemochromatosis exists in more than thirty percent of people from western European descent, implying that there must reason for this disease, and one idea is that it helped western Europeans survive the black plague. In the novel we learn how every living thing needs iron, including diseases, so people with hemochromatosis should attract diseases, but instead the disorder prevents diseases because iron is distributed in high amounts throughout the body except for the white blood cells, which fight infection. Because the white blood cells are lacking in iron, microorganisms, like the plague, can’t use those cells to gain iron, protect the person from the plague and making hemochromatosis beneficial to pass on to offspring at a time.

I also learned about type one and two diabetes, type one is commonly referred to as juvenile diabetes because it usually appears at a young age and is caused by an autoimmune disease, which causes the bodies cells to attack cells in the pancreas that produce insulin. Type two diabetes occurs when the level of insulin production is two low or other tissues are resistant two it. Dr. Moalem focuses more on type one diabetes because it occurs more in a specific population, northern European. The novel discussed the existence of a period of time called the younger dryas, a severe drop in temperature 13,000 years ago. This dropped in temperature severely affect northern Europeans because there methods of living had become inadequate, and the gene for diabetes had become useful. The novel explains how there is a species of frog that, in the winter, becomes completely frozen and survives because it’s blood has a high sugar ratio preventing ice crystals, and moves most of it’s water to it’s abdominal cavity, so when it freezes, the frogs organs are kept on ice. Since the frog’s high blood sugar helps it survive cold winters, the high blood sugar in humans with diabetes might have had the same effect during the younger dryas, which is one of the most unique and intriguing ideas I have ever heard.

Dr. Moalem then proceeds to describe the reason for high cholesterol, which I have previously assumed to just be an unfortunate hiccup in our genetics. I learned how we convert cholesterol into an important organic compound, vitamin D, through the use of sunlight. Even though sunlight helps create vitamin D it destroys folic acid, so different populations have different skin colors to manage the amount of sunlight they receive. This explains why people of northern European descent have lighter skin and a good chance of high cholesterol because they don’t see enough sunlight to hurt their folic acid, and need a lot of cholesterol to convert into vitamin D in the short time they do see the sun.

What questions do you still have?

Dr. Moalem does not leave many questions unanswered in his novel. One of the things that I would like to know is why oxygen is important to viruses and other microorganisms because I understand that humans and other animals use it for transporting oxygen throughout the body, but I wouldn’t expect microorganisms to need it for the same reason. I am also curios how the species of frogs that can freeze themselves are able to breathe if they are frozen and how organs are able to get oxygen if the heart is not pumping blood. Besides these few questions, I learned so much in just the first three chapters of this novel, that I cannot imagine what more unique ideas Dr. Moalem will teach.


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