Monday, March 8, 2010

Technology and "Natural" Selection

Jerry Coyne describes the human appendix as a vestigial organ which no longer has any use in our bodies (pg. 61). The appendix can become clogged and infected easily, a process which can cause it to rupture and kill a person. However, with the advent of appendectomy, we have reduced the chances of dying of appendicitis from over twenty percent to about one percent.

What effect does the relatively safe surgical removal of an infected appendix have on the process of natural selection as it pertains to humans and the appendix? Think of how the survival of affected individuals that would otherwise have died impacts future generations. What other examples of medical technology alter patterns of human survival, and how does the increased survival rate affect traits of future generations of humans? (Hint: think vaccines)


  1. The surgical process of removing an infected appendix prevents the process natural selection from eliminating those that are less fit to survive. Instead of appendicitis naturally killing these people off, the surgery allows those people to survive and pass their genes on to future generations despite the fact that these people are not neccessarily the best adapt to survive. Future generations could become increasingly weaker and weaker in fighting off diseases and infections on their own because surgeries allow less fit people to have offspring. These surgeries potentially weaken the human immune system of fighting off disease because the use of surgery makes a strong immune system to fight off diseases less neccessary. Vacinnes allow people to survive who normally would have died due to a bad virus. By allowing people with weaker immune systems to survive by giving them vaccines, we are propogating a cycle of progessively weaker immmune systems as the generations go on.

  2. I agree with everything that Annie said; we continue to keep people without immunity and with unfit genes (genes for appendixes, bad vision, bad hearing, etc) survive and have offspring.

    In the African savannah, hereditary nearsightedness would have almost certainly meant death. But now that people can put on a a pair of glasses, their genetic defects aren't so bad anymore. The survival of these individuals and their genes impacts future generations by spreading the vision impairment genes, which goes against natural selection. This is another example of our technology interfering with selection.

    I do not think that this affects us in a negative way. We have the brainpower to override natural selection and prevent death. Just because an individual has "unfit" genes doesn't mean that it is better for humanity if they were to die and not pass on their genes (think Beethoven, Helen Keller, anyone with glasses...). The fact that we can take our survival into our own hands despite any genetic deficiencies is a unique quality of human nature that allows us to contribute many valuable human beings to our society.

  3. Even though I agree with Anna's point of view that our ability to overcome hereditary deficiencies with modern technology is good and allows us to let many humans who wouldn't survive in the past survive now, I am scared at what this means for the future. Before, people that were "unfit" died before they could reproduce. Yet, according to the Population Reference Bureau, the human population has more than tripled (from 2 billion to 7 billion) since the 1950s. How long can this exponential growth go on? I am scared for a future where the earth is overpopulated. We could be facing worldwide starvation and overcrowding in big cities. This overcrowding could cause disease to spread much faster than before, causing worldwide pandemics of incurable diseases! Is this what we want modern technology to cause?
    Now, I am not suggesting that we start limiting the amount of babies we can have or kill unfit people. That is murder and genocide. Still we have to find a solution to what will be a huge problem in the immediate future. We cannot continue exponential growth or there will soon be a sharp decline in our population (the same thing we see when other populations grow exponentially). What solution (that isn't barbaric) can we find to help prevent this unavoidable crash? Or, is it inevitable?