Why do we age?
In: Biology
There’s a bit at the end of our DNA strands called a telomere. This ties the strand together somewhat how the little plastic bits on your shoelaces keep the ends from fraying.
Each time a cell divides the process of creating a new cell wears down the telomeres. There is “telomerase” in your cells that does work to repair the wear, but it doesn’t fully reverse it before the next division.
Eventually the telomeres wear down enough that errors start to make it into your cell division, which leads to degradation that manifests as aging.
Why don’t we have more telomerase to fix up the telomeres? Well because if you have too much telomerase you end up with cancer, which is a much more acute problem than aging.
Imagine two life forms. One is a complex life form that doesn’t die. One is a complex life form that does.
As environmental conditions change, the life form that does die will slowly evolve to adapt to those changing conditions. On the other hand, the undying life form will not. Over many, many years, this means the mortal life form will simply out-compete the immortal one.
So either you have a life form adapted for an environment that doesn’t change (much/in important ways) or you’re going to need death.
That death can either come via aging and ‘natural causes’ or it can come via the more direct approach of murder (by other life forms or the life form’s descendants).
Well aging is a bit of a human concept. This isn’t going to be the best answer.
Energy (and biological size) requirements means no animal can afford to carry an offspring to maturity in the womb (ie through pregnancy). So the offspring will be birthed pretty much as soon as it can have a reasonable chance to survive. Then it grows and matures independently.
At this point, there is another energy/evolutionary factor – it takes too much energy/complexity to keep an animal surviving long past where it can breed the next generation. Injuries, etc come into play and biologically it is too complex to have “infinite” regeneration potential while avoiding things like cancers etc. These are just the tradeoffs of biology.
So, as humans we call it “aging” but it is fairly natural. Obsolescence is a part of the outcome of evolution.
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