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Our closest worm kin regrow body parts, raising hopes of regeneration in humans

washington.edu

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Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#101

Post by badminton1 »

dpark wrote: post #67
badminton1 wrote: post #36

Probably because limb regeneration wasn't a favored trait during our evolution. e.g: we managed to survive and be fertile without it. Rather than limb regeneration we evolved pain and fear to prevent losing a limb in the first place. A similar question would be why aren't fruit toxic so animals stop eating them? Because they pass their genes anyways. Rather than that, animals that were too good at eating fruit, destr…

> Another interesting phenomenon are lemmings. Why lemmings kill themselves en-masse? Because they're too fertile. And as a population their own way to control their size is to mass suicide. Lemmings don't commit mass suicide. https://en.m.wikipedia.org/wiki/Lemming#Misconceptions

OK, fine. Disregard the lemmings.

They do die massively, but it's not intentional, I get it.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#102

Post by haywirez »

xux wrote: post #74

A lot of people are focusing on the mechanics, but it seems like humans don't generate body parts just like cells don't generate organelles. The entity is not _meant_ to exist by itself, but form a cohesive living group. A cell doesn't need to repair itself, it can simply clone itself and then die. A human being doesn't need to regenerate itself because it can reproduce and be cleared away. Evolution evolved to ensur…

> Evolution evolved to ensure the survival of the species, not the individual.

Depending on which view you take, evolution can be seen optimized for the survival of individual genes, not species[0]. In Dawkins' book, bodies are portrayed as mere useful survival vehicles for various genes.

(I'm ignorant on this, would love to read counterarguments from someone better versed!)

[0] https://en.wikipedia.org/wiki/Gene-centered_view_of_evolutio...

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#103

Post by badminton1 »

Gustomaximus wrote: post #61
badminton1 wrote: post #29

Earlier quoted context omitted.

Well, it depends what you consider to be "the best". If you have watched the olympics, you can see that different body types are better suited for different sports. A basketball player playing ping pong or viceversa? probably not very successful.

> Well, it depends what you consider to be "the best". There are clearly traits that are best, bar exceptionally rare scenario e.g. regenerating a lost limb, improved hearing, or improved longevity. So while I understand your analogy will fit some option, it is limiting too assume there will always be a trade off.

Well, we do not regenerate limbs, we just reproduce and make more of ourselves. If one dies then other survive and keep multiplying. Same as with limbs but at a population level.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#104

Post by coldtea »

toasterlovin wrote: post #90
piptastic wrote: post #87

Earlier quoted context omitted.

You don't have to regenerate parts to live long enough to have offspring. You can do it at like 15 years old. So evolution isn't going to help in that regard much.

Living for a long time after you have children is incredibly useful from the standpoint of genetic fitness. After all, grandparents play an important role in pretty much every human culture. And a grandparent with all their body parts is a whole lot more useful than one without.

>Living for a long time after you have children is incredibly useful from the standpoint of genetic fitness. After all, grandparents play an important role in pretty much every human culture.

In the time scale that matters to evolution, grandparents played absolutely no role for the Homo Sapiens, and neither did culture.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#105

Post by songgao »

Imagine you chop off your head, give both your head and body necessary environment to regenerate. It'd be like cloning.

Although the head gets a brand new body that works just as good if not better, while the body gets a head that is completely blank. Sounds pretty unfair to the latter...

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#106

Post by [deleted] »

PhasmaFelis wrote: post #64
SilasX wrote: post #7

Earlier quoted context omitted.

>Well, a plausible answer is that if we (or random mutations) re-enable those genes then the end result is simply a lot of cancer. Interesting idea, but does the risk of cancer have that much selective pressure? It tends to be the "last thing that kills you", after you live long enough to survive everything else. So it seems like any increased risk of cancer would have to be pretty high before it traded off against i…

> Interesting idea, but does the risk of cancer have that much selective pressure? It tends to be the "last thing that kills you", after you live long enough to survive everything else. You're assuming that's the default state, rather than the result of millions of years of cancer-preventing trade-offs. If e.g. being able to regenerate lost limbs gives you a 10% chance of dying of out-of-control cancer before reachin…

[deleted]

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#107

Post by erelde »

richardw wrote: post #98
xux wrote: post #74

A lot of people are focusing on the mechanics, but it seems like humans don't generate body parts just like cells don't generate organelles. The entity is not _meant_ to exist by itself, but form a cohesive living group. A cell doesn't need to repair itself, it can simply clone itself and then die. A human being doesn't need to regenerate itself because it can reproduce and be cleared away. Evolution evolved to ensur…

Those mechanisms are good enough to have brought us to this point, but that has no bearing on what kind of future we choose to create for ourselves. Metals rust and seep into the ground, but we dig them up and build spacecraft from them. Metals aren't _meant_ to do that, but we have some influence over our environment. We might end up having a similar influence over our cells.

This, to me, brings up the question of "where does myself ends and where does my environment begins?". I could change parts of my brain like I'm changing the environment around me, what would I be changing, the environment around me or myself directly? Both?

Classic greek Boaty McBoatface question I know. (cf Ship of Theseus)

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#108

Post by vacri »

arcticfox wrote: post #96
vacri wrote: post #92

Earlier quoted context omitted.

There are plenty of species where the male dies during mating, and squillions more where the male isn't around after mating. Evolution only requires that you get to reproduction, however that happens. It doesn't require that you're happy, sad, whatever, just that you reproduce.

> Evolution only requires that you get to reproduction, however that happens. It doesn't require that you're happy, sad, whatever, just that you reproduce. It requires that your offspring actually survive as well. Humans are, at least historically, exceptionally well-equipped to influence the survival of their offspring.

Humans also take figuratively forever to be self-sufficient. Herd animals are born with the ability to walk, for example. Humans take about 10 years before they can be taught to be even somewhat self-sufficient, which is a ridiculously long time in comparison to others.

So, given that humans are sexually mature before they're fully self-sufficient, that enhanced ability to support their offspring is not all advantage - it's actually required for the propagation of the species. If older folks weren't taking care of the younger ones, none of them would reach reproductive age.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#109

Post by dualogy »

erelde wrote: post #107
richardw wrote: post #98

Earlier quoted context omitted.

Those mechanisms are good enough to have brought us to this point, but that has no bearing on what kind of future we choose to create for ourselves. Metals rust and seep into the ground, but we dig them up and build spacecraft from them. Metals aren't _meant_ to do that, but we have some influence over our environment. We might end up having a similar influence over our cells.

This, to me, brings up the question of "where does myself ends and where does my environment begins?". I could change parts of my brain like I'm changing the environment around me, what would I be changing, the environment around me or myself directly? Both? Classic greek Boaty McBoatface question I know. (cf Ship of Theseus )

> This, to me, brings up the question of "where does myself ends and where does my environment begins?".

Good question this! Until you find a conclusive answer, ie. until you clearly define/delineate "myself" & "env", you can ignore your follow-up question as irrelevant sophistry:

> I could change parts of my brain like I'm changing the environment around me, what would I be changing, the environment around me or myself directly

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#110

Post by derefr »

toasterlovin wrote: post #90
piptastic wrote: post #87

Earlier quoted context omitted.

You don't have to regenerate parts to live long enough to have offspring. You can do it at like 15 years old. So evolution isn't going to help in that regard much.

Living for a long time after you have children is incredibly useful from the standpoint of genetic fitness. After all, grandparents play an important role in pretty much every human culture. And a grandparent with all their body parts is a whole lot more useful than one without.

The counterpoint being that in resource-scarce evolutionary environments, every grandparent (or even parent) that stays around is consuming resources that could instead go toward creating+maintaining an additional child.
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