Tuesday, March 9, 2010

Stunting Natural Selection

Coyne says that the idea of natural selection is when "species differ genetically from one another, and some of those differences affect an individual's ability to survive and reproduce in its environment, then in the next generation the 'good' genes that lead to higher survival and reproduction will have relatively more copies than the 'not so good' genes" (11). Explain how today's society has stunted the process of natural selection in humans.


  1. I consider today's society to be the "Survival of the Fit Enough". I think this because certain traits that helped our population grow are no longer being selected for. It used to be that having a larger brain would help in communication. This increased hunting success. Now, people can either buy food at a grocery store or pick off a deer from two miles away. Clearly, intelligence is no longer the selective advantage. Furthermore, people with increased IQ's tend to have less offspring than those with low IQ's. However, intelligence is just one example.
    The comforts of modern society have diminished the effect of natural selection. People that have traits that would be fatal in the wild can still survive and reproduce. Medicine can keep people that are prone to diseases or with genetic conditions alive long enough to pass these traits on. We have no hunters, so the slow and weak can reproduce just as well as the fast and strong.
    There are many changes that we are seeing in our population. For example, due to shoes, the size of the pinky toe is shrinking. Potential shifts could be far more influential to us. Trying to unnaturally select our populations traits brings many ethical questions.

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  4. Today's society has stunted the process of natural selection by allowing people who are less fit to survive, going against the process of natural selection. Natural selection promotes organisms that can reproduce more to pass their genes on more often, causing those characteristics that allow for survival and reproduction to become more common in a population over time.
    Going along with what John said, modern society allows people who are less fit to survive. One example of this is people with appendicitis. According to National Digestive Diseases Information Clearinghouse, appendicitis is caused by the enlarging of the appendix due to a buildup of feces. If the appendix is not removed, the appendix will burst and cause an infection to spread through the abdomen, a condition called peritonitis. Coyne states that due to surgery "the chance of dying when you get appendicitis is only 1 percent"(61). Surgery today has allowed almost everyone with appendicitis to live due to a simple procedure in which the appendix is removed. This prevents people with this disease from being naturally killed off, allowing people who are less fit to survive.
    Other Medical advancements such as medicine have allowed people to survive that normally would have died if they had contracted that disease. One example of a disease that shows the importance of medicine today is tuberculosis. Tuberculosis has been around for hundreds of years and has a high mortality rate because it attack the whole body. According to eMedicineHealth, the first treatment to fight tuberculosis was not found until the mid-20th century. Since then, more medicines have come out that help battle this disease in which bacteria infect the body and cause fever, weight loss, and weakening of the body. The use of medicines today such as Rifater has helped to treat people with these disease. By allowing people to survive who normally would have died due to a weak immune system, modern medicine allows people with weaker immune systems to reproduce and have offspring that have a weaker immune system. Medicine therefore prevents natural selection from occuring.
    The percentage of people with certain diseases is on the rise due to humans affecting the process of natural selection. According to Scientific Theory of Evolution, a form of eye cancer in children called retinoblastoma is a rare disease that is passed on through a dominant trait. This disease used to kill nearly all its victims. Due to modern technology, 70% of kids with this disease survive if they go through treatment. These kids that survive then have a 50% chance of passing the gene on to their kids. In this way, modern technology has inhibited natural selection by allowing bad genes to be passed on, causing the percentage of the population with certain diseases to rise rather than to decrease which would happen if natural selection was at work.