Blog 7: Continuing Evolution

Humans are constantly evolving in ways that most people do not even think about. One who studies evolution may wonder why our bodies were built the way they were. If natural selection favors better evolutionary traits, then why do our bodies still get sick? Why do we still experience pain? What scientists have determined is that these traits are not disadvantages, but they are actually defenses against what could kill us. For example, vomiting is a way that the stomach can protect the body against harmful gasses. While it may seem unpleasant in the moment, the gasses that were removed in the process of vomiting could have been deadly. Morning sickness among pregnant women acts as a similar defense system.

In a way, these responses continue to evolve to be like “smoke detectors”. A smoke detector is meant to wake people up and alert them of a fire. While these fires could be dangerous, in order to do its job, the detector must also alert people of the slightest dangers such as burnt food in the oven. Even though these false alarms would not have killed someone, the detector is set up to be triggered by even the slightest thing in an effort to keep people safe. Much like these smoke detectors, our bodies respond to even the smallest threats by vomiting, coughing, running a fever, etc. For example, if people never coughed, they would not be able to remove foreign substances from their bodies. While not coughing one time may not have an effect, never coughing would cause people to die of pneumonia. So the body must react to every instance.

Due to studies, we can also link evolution to the increase in heart diseases. During times of famine, natural selection favored bodies that were able to eat more fats because they were more likely to survive than thinner people who were not getting as much fat in their diet. So over time, we evolved to favor diets higher in fat. This is why our society has become dependent on fast foods and other unhealthy items. When eaten in moderation, they are necessary, however we evolved to crave fats, and now we suffer the consequences of eating too many fats.

Another example of evolution in current society is how young some girls are beginning to menstruate. It used to be that girls would begin at age 15, bear a few children while menstruating in between, and then stop. However, this is not the case anymore. Nowadays, females begin at age 12 or 13 and do not bear children for many years after that, if ever. Females used to average about 150 cycles as opposed to 400 now. This is because the diets we now consume allow women to be able to nurture a child at a younger age.

One final example that was not mentioned in the reading that I have always found interesting is wisdom teeth. While the majority of my friends simply believe that everyone has wisdom teeth and most people get them removed, they are mistaken. I, along with multiple members of my family, were born without wisdom teeth. Since they serve no function in today’s society and are consistently removed, I believe evolution is causing some people to simply not have them.

4 thoughts on “Blog 7: Continuing Evolution

  1. Hey! This was a very interesting blog post to read and I’ve enjoyed reading it! A lot of the ways you mentioned humans have evolved and are still evolving are not concepts I had put too much thought into previously.

    I also really appreciate your analogy to the smoke detector. I had never really thought about the mechanisms and reasons why humans do things as simple as coughing and how important they are to our own survival.

    I’ve also thought about wisdom teeth before. I wonder if more and more humans will become more evolved to simply not have them in the future. I’m sure this will likely be the case. I have mine but they have fully erupted and haven’t caused me any issues fortunately and do not need mine removed.

  2. Hi, great blog! You’ve made a lot of good points about how humans are continuing to evolve. Your point about why pregnant women throw up left me with more questions though. Why is this a triggered response even if the women haven’t ingested anything dangerous? I know this wasn’t a main point of your blog but it made me curious! These responses, like coughing and sneezing, are so interesting. Our bodies have amazing ways of keeping us alive. Your discussion about female menstruation is fascinating. I knew that girls were starting their periods earlier due to our diet, but I hadn’t considered that the greater reason behind this was because it means the girls are able to nurture children earlier. Very interesting! This makes me wonder about what the potential negative side effects could be of having so many more menstrual cycles.

  3. Hi Teresa,
    I agree as you say that our bodies have developed some defense mechanisms that allow us to eliminate foreign particles at a cost of an unpleasant experience. This does seem more efficient than an attempt to develop specific molecular defense mechanisms against one bacteria or virus because a whole host of invaders can be eliminated with vomiting or diarrhea prior to the infection reaching our bloodstream. When I considered your discussion of heart disease I first thought that we could not have evolved to favor a high fat diet, but I had to stop to consider it more carefully. The fact that humans enjoy or crave fats and carbohydrates is a function of our taste buds and cerebral mindset. Since these physiologic mechanisms are linked to genetic development, it is hard to deny that our current diet is linked to our genome. I hope, as you suggest, that we can modify these cravings to improve our heart health.
    -Jaclyn Kyko

  4. Your first paragraph really sucked me in! I also really liked your examples. They were personal and really easy to connect to the reader. I think I was thinking too broad when I was writing mine. Your last example about wisdom teeth made me look back and think about my own family. I guess a trait that a lot of my family members on my dad’s side has is a genetic condition where our skin aggressively heals itself and leaves a scar called a keloid. This could’ve appeared from a mutation to help heal wounds quicker probably because being a klutz runs in my family. I guess you can also look at other traits such as ADD (also genetic) and try to trace them back to why that mutation could’ve benefited a person and have them successfully pass down their genes.

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