Genes aren't what they used to be

The Survival of the Sickest by Dr. Sharon Moalem takes a look at different genetic issues and diseases and attempts to connect these issues to evolutionary factors and the history of the human race. The book presents how some disease that still effect us today like diabetes or even hemochromatosis are side effects of our evolution and although are troublesome today, were methods of survival for environmental issues like Younger Dryas and the plague.

What I found interesting was his link of hemochromatosis, an excess of iron in the blood, to Northern European survival to the plague. Apparently, those suffering from this issue have a lack of iron in their macrophages which causes their immune system to be able to better combat bacteria. Those with the genetic mutation were more likely to survive the mutation and pass this trait on to their offspring.  Certain environmental factors may cause traits to be more beneficial at a specific time than others, causing a sort of natural selection in humans to continue the lineage of those with a predisposition to beat whatever environmental threat in going on. He creates this same argument for diabetes and the great freeze that took places thousands of years ago, and how this trait that didn’t break down sugar gave the body antifreeze in this environmental time.

 Additionally, the same goes for bacteria. They also when given a threatened environment have a sort of natural selection.  The book notes that when penicillin was discovered, at first it treated staph, but eventually a percentage of staff infections were penicillin resistant. Just as humans were able to adapt to their harsh surroundings and reproduce offspring with genes for survival, so have bacteria. Just as we can use evolution to discover that natural selection has taken place so that species may survive and reproduce, we must also use that information to understand that by attacking bacteria in certain ways may speed along their natural selection evolution. Ewald was cited in this book stating that we should take control of their evolution by “favoring those mild strains and thereby domesticating those disease organisms, making them into mild versions of what they were before” (121). Through knowing our own history and evolution we should do what we can to not make bacteria stronger but to treat them in a way that would produce weaker versions of themselves.

The book through its examples of high cholesterol, hereditability, the Barker Hypothesis and others, what I gained from this book is that the human body is a complex system driven by primal forces to survive and reproduce.  Only when we trace what genes our ancestors used to survive in their harsh environment do these genes seem to be beneficial for us humans. Although we may understand some of nature and how our biological system works, the way in which we live our lives may not be the most beneficial. Just as what stress today isn’t dealt the same way as the Zebra running from the lion, certain issues in our body that could have been beneficial for us in the Savannah may not be as beneficial in the modern realm.