The Bubonic Plague: The Black Death

The bubonic plague, also known as the Black Death, was one of the deadliest pandemics in history. While mostly everyone who came into contact with the plague or another individual who was infected would soon become sick and eventually die for the deadly plague. But, there were a select few the didn’t become infected at all or became infected and then over came the sickness. How did some individuals live and most individuals die? This is because of natural selection. Natural selection is the process by which heritable traits the make it more likely for an organism to survive and successfully reproduce become more common in a population over successive generation. It is a key mechanism of evolution. Individuals who were resistant to the bubonic plague were later found to have a rare mutated gene called Delta 32. This gene provides immunity to the deadly
But, unlike sadness, depression can be passed down to passed down to offspring. Some mild and temporary depression is normal for an individual to experience in a lifetime but sever depression, or manic-depressive disorder, is not. If manic-depressive disorder is not normal and can be a huge threat to survival then why are we able to carry the gene and pass it down to our offspring? The answer is similar to why we experience sadness, “They probably offer some advantage, either in certain circumstances or in combination with certain other genes” (Nesse & Williams, Pg. 218). I believe that the purpose of depression isn’t to drive people to suicide or other extremely low states of depression that are life threatening. I think natural selection favors depression to help people become aware that they need to make some kind of change in their life. It drives individuals to reach a point of happiness again. Even for the people who self-isolate or become unable to connect emotionally with others and get trapped in their depression there is a way