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Comment by hackinthebochs | Hacker News Reader

Yup. I'm of the opinion that aging just is a "feature" of evolution. A population with aging has a significant fitness advantage over a population without aging so its not surprising that everything ages (the next generation is almost always more fit than the previous gen so the faster a population transitions to the next gen the more fit it is). But if aging just is a trait rather than some inevitable result of entropy, it leads one to be optimistic for reversing aging at least in principle.

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Aging as a feature doesn't make sense to me. It seems more likely to me that immortality simply hasn't been 'cracked' yet, intelligence that could create immortality would seem more likely to evolve first than immortality itself.

You have to get so many things just right for immortality to 'work', i.e. to actually be useful in a survival context. It does no good for creatures to not age if they lose a significant amount of viability.

But real immortality in the complete reversal of aging, I think would be an immense advantage. Instead of having to teach your young over a very short period of time the tricks they need to be viable adults, creatures could super-specialize. One creature could supply all the food needed for a huge colony. They'd just get better and better at exploiting their niche and other creatures could find other niches.

I think if intelligence hadn't 'gotten there first', immortal creatures would be running the show.

> One creature could supply all the food needed for a huge colony.

We call this a "single point of failure".

Other creatures could provide security.

Against a really clever predator, perhaps with wings? Against accident and illness? Against a change in circumstance such that those overspecialized strategies no longer work sufficiently well or at all?

A colony could stockpile food for the interrim period where the backup could be trained up.

Trained up by whom? All that's left of the colony's institutional knowledge on the subject of provisioning is an owl pellet's worth of tiny bones and hair.

With immortality, institutional knowledge doesn't have to go away. Everybody can know everything, and the specialist that has all the experience dies, then a new one can just be selected, and the whole colony can pick up the slack until the new specialist is experienced enough to do it all himself.

Everybody becomes T-shaped.

So immortality implies perfect recall, such that skills not exercised cease to grow rusty and fade with time?

Your experience could serve as limitation to your view of the world. Younger ones without the baggage of experience, has greater chance of discovering new approaches. Due to this, population with changing generations, might be more intelligent than one without these clean slates.

Immortality has been cracked. There are a number of "immortal" species that do not age.

Whether a population that ages beats out one that doesn't doesn't matter as much as whether an individual that ages beats out one that doesn't.

Well the issue is whether a gene survives. Sometimes the individual is a good proxy for this, sometimes the population. Sometimes you just gotta consider the dynamics of a gene in a sea of other genes.

In the case of a supposed aging gene, consider that genes themselves preferentially want to exist in more fit organisms. If a gene could somehow manage this (i.e. be embodied with more fit genes), it will itself spread. But this is exactly what an aging gene does! Consider how an advantageous gene spreads through a population. This spread is a function of the number of generations that have passed. So a gene that could speed up the passing of generations will increase its own likelihood of existing in more fit organisms (increasing its own fitness), as advantageous genes within the population spread faster and are more frequently "paired up" with the aging gene. But the subpopulation with the aging gene is more fit than the subpopulation without it since the time for advantageous genes to spread is decreased, and so the aging population overtakes its counterpart.

I don't think this is correct. I've never heard of any evidence for pro-aging genes, but I have read molecular biology rebuttals against this theory (Stephen Jay Gould or perhaps textbook sources, though unfortunately I can't recall well enough to cite them).

You don't need extra genes or information to prefer organisms that age out of reproductive fitness. If advanced age during reproduction confers lower fitness, then the offspring are automatically less fit. While you could argue that there would be a competition for resources amongst the young offspring, this isn't much different than other scenarios that produce less fit or disabled offspring.

True, you don't need extra information to prefer organisms that age out of reproductive fitness, but you might need extra information to ensure a timely death. It remains to be seen whether aging is just due to entropy or that regenerative processes are programmed to stop after a certain amount of time. Programmed death confers very specific fitness advantage to one's offspring as you're no longer competing with them for resources.

The sharing of genes within a population creates a nice analogy between the population and a single organism. Programmed death for members of an organism is a standard feature of evolution. It's not implausible that such a feature exists at the level of population as well.

This Wikipedia article has a review of several evolutionary aging theories:

https://en.wikipedia.org/wiki/Evolution_of_ageing

None of these has been proven or widely accepted, and the entire class of theories has many rebuttals. They are interesting to consider, though.

In many cases, it might matter much more. There are many species of animals that reproduce mostly within their own group. Group selection effects are much more pronounced in these species.

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