On page 19 of chapter one, Dr. Moalem
talks about John Murray, a doctor, that was working in a Somali
refugee camp. During his time there he noticed that many of his
patients had pervasive anemia and despite there exposure to several
diseases, they showed no sigh of infection. When treating his
patients, he only treated half of them with iron supplements for
anemia. Soon after the treatment, the patients that had received it
began to get infected with the diseases that had not affected them in
the past. According to the book it was the iron that caused the
infection rate to skyrocket.
People from that area of the world are
better equipped to deal with those surroundings than we are. This was
caused by evolution over a long period of time. This related to big
idea 1 ( the process of evolution drives the diversity and unity of
life) in that the evolution of the people in that area has helped
them to survive in areas people from our environment could not.
Explain what may have caused anemia to
become so common in Somalia and the surrounding are. Also find and
explain how the environment could have played a role in the evolution
of the Somali people. Also explain how anemia, a harmful disease,
could have been a selective advantage and how it may have helped
along natural selection.
According to a study conducted in 2010 by the Food Security Nutrition Analysis Unit, nearly half of all women and children in Somalia have anemia. Approximately “50 percent of all women, 30 percent of all school aged children and 60 percent of children fewer than five” were labeled as anemic. It’s believed that anemia is caused by various factors including frequent exposure to diseases and a lack in key vitamins and minerals with their meals. This reflects Dr. Murray’s observation that there was repeated exposure to diseases like “malaria, tuberculosis, and brucellosis” (19). Poor diets and the lack of certain nutrients, like important building blocks such as carbohydrates and fats, can affect the body’s ability to maintain homeostasis which would affect Big Idea 2 (biological systems utilize free energy and molecular building blocks to grow, reproduce, and to maintain dynamic homeostasis).
ReplyDelete(http://www.garoweonline.com/artman2/publish/Health_26/Somali_women_and_children_at_risk_of_anemia_printer.shtml)
Somalia is also located in the Horn of Africa and is a place ravaged by war and droughts. These disasters have led to many displaced populations as well as extreme poverty. In an evolutionary sense, people living in this terrain needed to be able to adapt to changing environments as well as withstand periods without rain. The droughts in the region could have contributed to a limited food supply and therefore the people themselves had very little to eat and as a result consumed little amounts of food with not enough nutritional value. The lack of iron in their systems would lead certain members of the population to become anemic.
(ftp://ftp.fao.org/es/esn/nutrition/ncp/som.pdf)
Anemia could have given the people a selective advantage because there is a lack of iron supply within the body. Many pathogens, such as tuberculosis, use iron to “feed and multiply” (13). The iron these invaders are looking for can easily be found within our macrophages. We’ve learned that macrophages are part of our immune system, and they engage in phagocytosis (engulfing and digesting of the pathogen). Macrophages that have a lack in iron supply is advantageous because they are able to fight off invaders and at the same time deprive the pathogen of a food supply. In an environment where disease is prevalent, humans who are able to defeat the diseases more effectively due to less iron supplies would be favored for and would have a better chance of surviving and reproducing.
Faith Teodoro (fteodor4@students.d125.org)