The Survival of the
Sickest, by Sharon Moalem delves into the subject of evolution and why
certain hereditary diseases continue to be passed on for generations regardless
of their negative effects. It seems to me that as we develop more treatments
for genetic diseases, evolution may slow down. This is because, if treated, many
diseases do not prevent people from reproducing, or even living lives that are
much shorter than a person without the disease. The same goes for any disease
that may have killed people who were weaker than others. This is something that
has fascinated me since I was in kindergarten and got Scarlet Fever. I had
recently read the children’s book The Velveteen Rabbit, in which the little boy
in the story dies of the very same disease. So, when the doctor told me what
was wrong I immediately started crying, thinking I was going to die like the
boy in the book. My mother then explained the concept of medicine, and how people
generally do not die from things like Scarlet Fever anymore, and I felt better
again in a few days. I do not know about studies that have been done on this
subject, but I would be interested to read them. I am not quite sure how I feel about this idea because while evolution is important for our species to survive in the long run, I would not be willing to compromise the vast benefits of modern medicine and the strides they have made for people all over the world.
It also seems as though some genetic diseases, such as
hemochromatosis are able to pass themselves in to offspring because they do not
result usually in serious health issues until a person is older and could have
already had children. For example, the author’s grandfather passed his
hemochromatosis gene onto his children because he was not diagnosed with
Alzheimer’s until he was 71 years old, long after his prime for having
children. The gene has been passed on to his grandchildren and may be passed on
to his great grandchildren in the same manner. I am also interested in the
environmental factors that cause the genes for hereditary diseases such as the
gene for hemochromatosis to express themselves.
I think that it is interesting to consider that medicine might impede on the evolutionary process because it treats those who are ill, allowing them to pass on their bad traits. However, diseases such as hemochromatosis both help the person with it while having negative effects. It could be something good to have if the person can regulate the amount of iron in their body so they can have a strong immune system while not suffering the effects of iron build up. I feel like it is a good gene if the person regulates it by such things like getting their blood drawn and eating foods with less iron. This way they can reap the benefit of having a strong immune system.
ReplyDeleteI also agree that it is interesting to examine evolution in regard to the progression of heritable disease. Kate, I think you make a good point by saying that many diseases persist in the human population because they do not affect an individual's ability to reproduce. While reading Dr. Sharon Moalem's book I found it amazing to think that the genes we possess today are a culmination of thousands of years of complex development and change. What I found to be most provoking about Moalem's text was the idea that vaccines and modern medicine may heavily influence the health of our human successors. By manipulating immunological responses in humans (via vaccines and antibiotics), we cannot spread the immunity to our offspring. Evolution is a population based phenomenon and we cannot control that is out of our control on the individual level. A final thought on the topic of vaccines: I read the book Deadly Choices by Paul Offit, which explained the consequences of the "anti-vaccine" movement. It is quite freighting to think about the ramifications of having a large population of immunologically vulnerable individuals, where the prevalence of diseases that have been easily preventable for decades (in the developed world) begin to resurface.
ReplyDeleteI never thought about the possibility that medicine is hindering the evolution process for humans before reading this book. Even though medicine will prevent the loss of harmful genetic disorders from disappearing, one could argue that the evolution if the human brain is the source of this occurrence. Since we are becoming more intelligent with every generation, we are able to eliminate these problems through the increasing of medical knowledge for the benefit of the human race. I agree with Katie and believe that we should not consider giving up the benefits of modern medicine in order to progress evolution. We invented vaccines for the purpose of curing diseases so that we won't have to wait for evolution to rid us of this problem.
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