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It just dawned on me that getting old and dying is most likely an evolutionary chicken and egg problem. If you didn't get old and die, evolution of your specie

It just dawned on me that getting old and dying is most likely an evolutionary chicken and egg problem. 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.

jhedwards 7y ago
I would imagine there's a fundamental limitation in DNAs ability to be copied over and over without information loss.
- SolarNet 7y ago
  Sure, but we can correct for that, we have the ability to reliably store copies of the information in DNA (a person's full genome is only a few gigabytes) with error correction (or at least verification).
  - thfuran 7y ago
    Our cells are mostly diploid. But some organisms have many more copies of each chromosome - strawberries have eight. With that kind of redundancy, it should be vanishingly unlikely for a random error in DNA replication to make it into a majority of copies and any systematic error severe enough to cause it probably messes up the cell enough for it to be culled by other mechanisms.
- aflag 7y ago
  Hasn't it been doing so for billions of years now?
  - jjoonathan 7y ago
    Only with strong selective pressure killing off the bad mutations (with is many/most of them). "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 :)
SolarNet 7y ago
Exactly. Relatedly, we are still evolving, and social policy is part of what dictates this.
DuskStar 7y ago
> 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 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)
- simcop2387 7y ago
  > 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 https://en.wikipedia.org/wiki/Turritopsis_dohrnii
ericmcer 7y ago
Maybe there were some early species that didn't die naturally, or lived for a very long time? Definitely an interesting theory.
whatshisface 7y ago
No, only reproduction is required. If there was still an early Hominid walking around, we wouldn't be any dumber.
- oh_sigh 7y ago
  The problem is that old species members generally rely on the same resources as young species members. So if you're in a resource-constrained environment, you need to clear the old out.
  - whatshisface 7y ago
    Death through old age isn't the only way to do that.
throwaway_law 7y ago
Biological immortality in plants and animals isn't unheard of. 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.
- mensetmanusman 7y ago
  Are you saying there is a floating jelly fish in the ocean that is 500 million years old (‘years old’ in the common parlance of usage)?
  - skosch 7y ago
    The life/reproduction cycle of jellyfish makes it difficult to talk about "common parlance" age. Someone even made a website about it: https://immortal-jellyfish.com/ https://immortal-jellyfish.com/
  - djrogers 7y ago
    Highly unlikely - statistically speaking, predation and disease would kill any individual specimen long before 500M year passed. That said, there are ‘immortal jellyfish’ that do not die of aging - don’t worry about an uprising though, they can be killed! [1]https://en.wikipedia.org/wiki/Turritopsis_dohrnii https://en.wikipedia.org/wiki/Turritopsis_dohrnii
    - throwaway_law 7y ago
      >predation and disease would kill any individual specimen long before 500M year passed. 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.
dcolkitt 7y ago
No. You're succumbing to the fallacy of group selection. Evolution operates on a gene-specific level. A trait that maximizes an individual's inclusive genetic fitness at the expense of the species will always out-complete. 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.
- derefr 7y ago
  Wouldn't a gene prefer to transmit copies of itself into descendants that replace all the other genes in the DNA it shares, with better fitness-maximizing ones? 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.
  - dcolkitt 7y ago
    Yes, if a gene's surrounded by copies of itself, then there might be certain scenarios where it will destroy a copy of itself to help other copies of the same gene. 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.
zarkov99 7y ago
If a mutation occurred in an individual such that it would not age, while everything else remained the same, that individual would have more reproductive opportunities and so would its offspring, but there would still be differential success, that is not all individuals would reproduce at the same rate. So you would still have reproduction, heredity and differential reproductive success. So evolution would continue. The fact that all creatures age suggest there is some fundamental trade off between longevity and other types of fitness.
- WhoBeI 7y ago
  Buildup of damage due to radiation, chemicals and the like would introduce more errors/damage into offspring.
  - copperx 7y ago
    I like David Sinclair's idea that while DNA can be considered digital data, copying it is an analog process and we end up with copies of copies of copies, each a little worse than the previous one, while DNA is still intact. It sounds too simple to be true, but it's an interesting information theoretical based hypothesis.
kgin 7y ago
Dying isn't required for evolution. 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.
- spenczar5 7y ago
  Wouldn’t that mean there is evolutionary pressure to keep reproducing as long as possible (and so, evolution should lead you to live forever and keep making babies)?
  - kgin 7y ago
    Not sure about the exact math here, but there is diminishing "returns" to the genes with every additional offspring. Going from "zero offspring" to "one offspring" is the biggest jump genes can make. Two is 100% better than one. But three is only 50% better than two. Four is only 33% better than three.... etc 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.
solotronics 7y ago
This is only true if you have limited resources and still expand the population by reproduction. When we start colonizing space living forever would not be a problem.
deleted 7y ago
[deleted]

jhedwards 7y ago

I would imagine there's a fundamental limitation in DNAs ability to be copied over and over without information loss.

SolarNet 7y ago
Sure, but we can correct for that, we have the ability to reliably store copies of the information in DNA (a person's full genome is only a few gigabytes) with error correction (or at least verification).
- thfuran 7y ago
  Our cells are mostly diploid. But some organisms have many more copies of each chromosome - strawberries have eight. With that kind of redundancy, it should be vanishingly unlikely for a random error in DNA replication to make it into a majority of copies and any systematic error severe enough to cause it probably messes up the cell enough for it to be culled by other mechanisms.
aflag 7y ago
Hasn't it been doing so for billions of years now?
- jjoonathan 7y ago
  Only with strong selective pressure killing off the bad mutations (with is many/most of them). "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 :)

SolarNet 7y ago

Exactly. Relatedly, we are still evolving, and social policy is part of what dictates this.

DuskStar 7y ago

> 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 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)

simcop2387 7y ago
> 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 https://en.wikipedia.org/wiki/Turritopsis_dohrnii

ericmcer 7y ago

Maybe there were some early species that didn't die naturally, or lived for a very long time? Definitely an interesting theory.

whatshisface 7y ago

No, only reproduction is required. If there was still an early Hominid walking around, we wouldn't be any dumber.

oh_sigh 7y ago
The problem is that old species members generally rely on the same resources as young species members. So if you're in a resource-constrained environment, you need to clear the old out.
- whatshisface 7y ago
  Death through old age isn't the only way to do that.

throwaway_law 7y ago

Biological immortality in plants and animals isn't unheard of. 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.

mensetmanusman 7y ago
Are you saying there is a floating jelly fish in the ocean that is 500 million years old (‘years old’ in the common parlance of usage)?
- skosch 7y ago
  The life/reproduction cycle of jellyfish makes it difficult to talk about "common parlance" age. Someone even made a website about it: https://immortal-jellyfish.com/ https://immortal-jellyfish.com/
- djrogers 7y ago
  Highly unlikely - statistically speaking, predation and disease would kill any individual specimen long before 500M year passed. That said, there are ‘immortal jellyfish’ that do not die of aging - don’t worry about an uprising though, they can be killed! [1]https://en.wikipedia.org/wiki/Turritopsis_dohrnii https://en.wikipedia.org/wiki/Turritopsis_dohrnii
  - throwaway_law 7y ago
    >predation and disease would kill any individual specimen long before 500M year passed. 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.

dcolkitt 7y ago

No. You're succumbing to the fallacy of group selection. Evolution operates on a gene-specific level. A trait that maximizes an individual's inclusive genetic fitness at the expense of the species will always out-complete. 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.

derefr 7y ago
Wouldn't a gene prefer to transmit copies of itself into descendants that replace all the other genes in the DNA it shares, with better fitness-maximizing ones? 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.
- dcolkitt 7y ago
  Yes, if a gene's surrounded by copies of itself, then there might be certain scenarios where it will destroy a copy of itself to help other copies of the same gene. 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.

zarkov99 7y ago

If a mutation occurred in an individual such that it would not age, while everything else remained the same, that individual would have more reproductive opportunities and so would its offspring, but there would still be differential success, that is not all individuals would reproduce at the same rate. So you would still have reproduction, heredity and differential reproductive success. So evolution would continue. The fact that all creatures age suggest there is some fundamental trade off between longevity and other types of fitness.

WhoBeI 7y ago
Buildup of damage due to radiation, chemicals and the like would introduce more errors/damage into offspring.
- copperx 7y ago
  I like David Sinclair's idea that while DNA can be considered digital data, copying it is an analog process and we end up with copies of copies of copies, each a little worse than the previous one, while DNA is still intact. It sounds too simple to be true, but it's an interesting information theoretical based hypothesis.

kgin 7y ago

Dying isn't required for evolution. 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.

spenczar5 7y ago
Wouldn’t that mean there is evolutionary pressure to keep reproducing as long as possible (and so, evolution should lead you to live forever and keep making babies)?
- kgin 7y ago
  Not sure about the exact math here, but there is diminishing "returns" to the genes with every additional offspring. Going from "zero offspring" to "one offspring" is the biggest jump genes can make. Two is 100% better than one. But three is only 50% better than two. Four is only 33% better than three.... etc 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.

solotronics 7y ago

This is only true if you have limited resources and still expand the population by reproduction. When we start colonizing space living forever would not be a problem.

deleted 7y ago

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