In pages 89-91 Dr. Moalem talks about malaria. Malaria is an extremely dangerous disease that kills one million people per year. This occurs most in Africa because the disease comes from mosquitoes that infect the blood. Because the blood goes quickly through the blood cycle it kills painfully through a series of fevers and chills. To combat this, people can get G6PD deficiency. This deficiency may cause death, but it helps to combat malaria. This relates to Big Idea 1: The process of evolution drives the diversity and unity of life. To survive, we eat fava beans that potentially kill us from G6PD deficiency. The more dangerous disease is Malaria so the Africans decide to have the other mutation to prevent Malaria.
Like Malaria, there are many diseases that are more dangerous than others. To prevent malaria some humans take on a genetic disease that decreases chances of malaria. This disease may effect us negatively, but helps us survive more dangerous diseases. Like Malaria and fava beans find a disease that our bodies can prevent using another disease. Research both diseases and explain what they do to the body. Explain how the second disease helps to prevent the more damaging disease.
(Sam Lee salee4@students.d125.org)
A disease that is able to combat an even worse disease was mention in the first chapter of Survival of the Sickest. This disease is called Hemochromatosis and according to page 2, "this is a hereditary disease that disrupts the way the body metabolizes iron." In a person with Hemochromatosis, the body continuously thinks the body doesn't have enough iron, so the body absorbs iron unabated. Without treatment to this disease hemochromatosis can lead to liver failure, heart failure, diabetes, and cancer according to page 2 as well. In the book, Dr. Moalem takes a side trip to talk about the Bubonic Plague. The Bubonic Plague was a deadly outbreak that killed more than 25 million people in Europe. The cause of the disease occured from a bacterium called "Yersinia pestis" which found a home in the body's lymphatic system and created painful swellings in the armpits and groins which eventually burst through the skin. However, there were people who survived the Bubonic Plague that killed every nine out of ten people when airborne (page 9). The reason for this is iron. our macrophages, white blood cells that fight off pathogens, contain iron and in a person who has hemochromatosis has less iron in their macrophages. So in a normal person, when the macrophage encounters the bacterium, the bacterium uses the iron in the macrophage to grow and spread the infection throughout the lymphatic system. However, since a person who has hemochromatosis has less iron in their macrophages, the macrophage is able to stall the infection before it takes over. This is how people survived the plague, because the had Hemochromatosis.
ReplyDelete(citation: http://www.med.uottawa.ca/sim/data/Biol_Genetics_Hemochromatosis.htm)
This relates to big idea number 1 because having hemochromatosis during the time of the bubonic plague meant that you can dodge the airborne disease and survive and reproduce. However, when the bubonic plague ends having hemochromatosis becomes a selective disadvantage because you don't have enough iron in your body or you have too much iron.