Aging Is a Programmed Remodeling of the Body's Cell Society, Not Random Decay
Aging may be a program, not a breakdown
By profiling 21 million mouse cells across 14 tissues and five life stages, Rockefeller University cell biologist Junyue Cao found that aging unfolds in discrete, coordinated waves: vulnerable cell types are depleted early, then immune cells expand. Only about a quarter of cell subtypes shift strongly with age, and the same genomic regions reliably open or close at each stage, suggesting aging is a programmed process that begins before age 30 in humans.
The destruction of the system is programmed at a very early stage.
- anonporridge
It's probably a bit of both.
Maintaining order and fighting entropy is hard, but also planned obsolescence is a good thing for systemic resilience.
You have to regularly clear out the old for at least two reasons...
a) keep the process of creating new things well exercised. "We can't build that anymore. We don't know how." A factory that builds things that last too long eventually goes out of business.
b) prevent old things from monopolizing resources due to more time to compound interest. Otherwise, you end up with Saturn devouring his son.
- aeturnum
There are animals that don't "age"[1] so of course it's programmed. There's a balance between how often you want to recombine genetics and how long you want to be able to remember. It seems like a better system would have humans decline differently (i.e. no dementia) but having people grow old is almost certainly beneficial to the species.
[1] Their risk of death does not increase after reaching adulthood. I.e. every year after adulthood has the same risk of unexpected death. Humans and other animals that age have their risks of death climb in "old" age.
- jvanderbot
I've always thought eternal life would steal from the next generation if resources are scarce. If your reaction times, intelligence, etc are always good, and your experience and memories get better, it just seems like you'd out compete your kids and younger cohorts. All well and good but basically stops genetic turnover that got us to this point.
OTOH, you'd accumulate uncurable disease, injuries, etc as well. Maybe you become a disease resevoir inside your own growing family. Or you pass on as-yet-unknown genetic anomalies that are unhelpful, and you do so forever.
Granted that's a modern take, and in particular a modern rpg-like take. Regardless though getting rid of oldies seems like a reasonable way to move a species forward if natural selection is driving "forward".
- ____tom____
In biology, there are always many causes, of course.
I wonder if people are familiar with the hypothesis of parasite-driven aging.
Parasites are vastly more prevalent than most people in modern, sanitary, medicated societies realize. Studies show that over half the biomass in a region may be parasitic.
Parasite frequently keep the host alive, but inhibit reproduction. This leaves the host alive, and competing with healthy members of its species for resources, but no capable longer reproducing. It's evolutionary dead weight.
Death is basically "turning it off and on again", just as you would do with a computer, and for very similar reasons. It clears the accumulated parasites and starts fresh.
This would also help explain why death is strongly conserved.
- thinking_cactus
I think death has some actual benefits. Yes, some of our comfort with death comes with learning to live with its inevitability, but it has genuinely some upsides. I think they have some to do with being able to change things and institutions, but mostly it centers around our brains and psychology. Our life cycle is connected to how our brain develops and matures, inherently I think.
For example, if you go through some events in your childhood, they may stick with you until your death, as an inevitable part of you. Sure, treatment helps, but probably some memories you can't just erase.
Recycling things into a next generation, with probably better living conditions seems like generally pretty positive thing.
Also, some time you'd probably start to stop learning, not necessarily due to brain aging and neuron death, but simply because of basic architecture of our brain and how information solidifies and it starts to become more difficult to learn new things. We are a little more bored of most things and a lot of mystery and wonder diminishes somewhat.