If you didn't get old and die, evolution of your species would grind to a halt.
Getting old and dying is required for evolution to transpire.
I can't see any reason why it must be an absolute truth.
> Getting old and dying is required for evolution to transpire.
I don't think this is actually the case - only dying is required, not the getting old part. If a lion is still having no trouble catching zebras at 20, why shouldn't he stick around having kids? (The answer is probably something along the lines of "keeping this gene carrier at maximum health is significantly harder than spreading through fresh, if diluted, gene carriers" - though some species do seem to manage agelessness, most intriguingly the naked mole rat)
Though far more removed from us or many other things, some Jelly Fish take this even further by reverting to earlier stages of life. https://en.wikipedia.org/wiki/Turritopsis_dohrnii
Genes most definitely do not want to promote evolution in any sense. Since evolution by definition implies the replacement of currently existing genes with new genes.
That is, if a gene's options are "copy into clone" or "copy into 100% optimal genetic superman, with the only common gene being me, left completely untouched", I assume any given gene would "choose" the latter.
Which is to say, presuming a given gene is already helpful and is "core" to the organism's functionality, that gene would see evolution as a helpful service that causes it to end up copied into better-performing descendants, rather than same-performing descendants.
This also serves as a decent explanation of why sexual reproduction persists even in species that can also parthenogenetically reproduce: the "good" genes are betting on being retained, and getting the "bad" genes culled out in the process.
For example apoptosis happens all the time in human cells. If a cell believes it's infected by a virus or a cancerous mutation, it will voluntarily destroy itself. That's because its continued existence threatens its genetically identical cellular neighbors. Thus genetic inclusive fitness is maximized.
But what absolutely wouldn't happen is such self-sacrifice on a species wide level. Two random members of a species are not closely enough related for self-sacrifice to maximize inclusive genetic fitness. Almost certainly a non-complying free rider mutation would arise in one or more individuals, and exploit the other species' members altruism.
The hypothesis was that aging evolved as an adaptation to accelerate the evolution of the species. To see the absurdity of this hypothesis, consider that if this logic held, then mate guarding would definitely not exist. In fact just the opposite, males would routinely solicit the highest-quality males they could find to mate with their females. And be happy about it. After all this would also accelerate species wide evolution, at the expense of individual fitness.
Which means that, if there's a trade-off that involves killing the current host of the gene, in exchange for creating a new host (a descendant) that has the same gene, but is otherwise more inclusively-fit because it has better other genes—then any given gene will "want" to take that trade. Thus the evolution of reproductive strategies that require the deaths of one or both parents.
Mate-guarding (and, really, sexual reproduction preference generally) can be understood as a desire of your more-fit genes, to kick out your less-fit genes and replace them (in your descendants) with more-fit immigrant genes, to build a more-inclusively-fit descendant where the gene has higher likelihood of continuing the next step of exponential-spread-to-fixation.
Take Jelly Fish, they are biologically immortal, been around 500 million years, not to bad. They were the first animals to evolve nervous systems, not sure the timeline of the biological immortality evolution, but they must have continued evolving because there are different species (some have evolved eyes and others not) and I believe all species are biologically immortal.
Only via predators. The immortal Jellyfish not only don't die from aging, they don't generally die of disease, starvation, temperature changes or any other stresses...in fact it is those stresses that trigger their reversion from sexual maturity to biologically rewind to a polyp colony where they begin the start of their life cycle all over.
I tend to agree statistically speaking it seems highly unlikely, but its such a bizarre thought experiment, I can wind up concluding it is statistically highly unlikely there isn't Jellyfish in the wild that are older than the dinosaurs. Unfortunately, we can't age these Jellyfish.
Unfortunately we can't age these Jelly fish or even confirm they have undergone the reversion transformation process (except under lab observation).
So while I am not saying yes, a single jelly fish has lived the entire 500 million years, its certainly possible and the idea behind biological immortality. Maybe one day we can figure out a way to age them and find some older than the dinosaurs.
It's just that after you reproduce and get your offspring on their own feet, continuing to live is optional (for evolution), so no optimizations evolved to continue life far beyond that.
Evolution isn't trying to kill you, it just doesn't care about helping you beyond reproductive age.
So once you get to like 10 kids, you're really not getting much more evolutionary advantage for each additional kid. You don't have the same relentless pressure that privileges genes that are provide extreme longevity.
It sounds too simple to be true, but it's an interesting information theoretical based hypothesis.
"But most human babies don't die. There are a bunch of mutations per generation, but not an exponentially compounded bunch of infant deaths, so how does our population get rid of bad mutations?"
Because sperm are unit tests. The overwhelming majority of them die. You've got to regularly run the unit tests if you want to keep the codebase healthy :)
Relatedly, we are still evolving, and social policy is part of what dictates this.