Why Do We Die?

Darwin taught us that only the fittest survive. The term “fittest” has seen a lot of ink being spilled since. However, it is worth it also to spend some time discussing the term “survive.” A discussion is necessary because we all die. But why? Why don’t you just live forever? Or at least why can’t the fittest evolve genetically to be able to live forever? Surely, all it would take would be a few tweaks in your genetic makeup? Then you could live forever without having to wait for some medical miracle to arrive. Is there possibly an evolutionary reason for us to carry the trait of senescence or have a terminal life?

Purely biologically speaking, the purpose of your life is only to produce offspring that can carry your genes. In 1957 George Williams first proposed the theory of antagonistic pleiotropy. The theory attempts to resolve the contradiction of a gene carrying multiple traits – one which is beneficial to your survival and another that is detrimental. It is in some sense the process of selection. If you are healthy early in life and this can result in healthy offspring, trading this trait for death later on in life is worth it.

The way this manifests in your body is called Autophagy. Autophagy is the process by which your body destroys its dead cells. When you are young, autophagy works in your favor helping you eliminate your dead cells. As you age, the process of autophagy slows down finally completely deteriorating or breaking down, which ultimately results in death. This trade-off biologically speaking is worth it. Scientists are now attempting to turn off the process by which autophagy stops working. If they do, it will be interesting to see the impact on the way your body functions in early life. Doesn’t nature always seek harmony?