Live data from Hacker News

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

washington.edu

21–30 of 167 posts

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

#21

It seems like the cells in a worm are relatively position-independent, so they can regrow using only local information. If you lopped off your leg, a cell would need to know how much of the leg to regrow to get to the kneecaps, how much to grow to get to the foot, or more. If you chopped off a foot, it seems hard to know which parts need to be regrown and which don't. There's a lot of complexity in a foot.

This has to be a solved problem unless the womb offers some sort of telemetry.

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

#22
post #7
post #2

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. A reasonable default assumption is that each switch in our "genetic configuration" is set to a quite good value. The only exception is if we see a feature that is beneficial at a high calorie cost - those features have been (reasonably) optimized away during our evolution, but would be use…

>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…

Cancer is probably selected against to a degree.

At least for most normal healthy males, not dying prematurely of cancer means you've got probably 50 or so years to pass on your genes. If a cancer causing mutation kills you at 30, you may still have the chance to pass on your genes, but you're still being outcompeted in the larger gene pool by those who don't die early and have more children than you. And if not you, then your children who die prematurely may not procreate. Evolution doesn't really have much noticeable effect at the scale of single generations anyways.

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

#23

It seems like the cells in a worm are relatively position-independent, so they can regrow using only local information. If you lopped off your leg, a cell would need to know how much of the leg to regrow to get to the kneecaps, how much to grow to get to the foot, or more. If you chopped off a foot, it seems hard to know which parts need to be regrown and which don't. There's a lot of complexity in a foot.

It's more than just worms that regenerate body parts. Some salamanders can regenerate whole limbs.

https://www.youtube.com/watch?v=EsCSwVx3GvA

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

#24

It seems like the cells in a worm are relatively position-independent, so they can regrow using only local information. If you lopped off your leg, a cell would need to know how much of the leg to regrow to get to the kneecaps, how much to grow to get to the foot, or more. If you chopped off a foot, it seems hard to know which parts need to be regrown and which don't. There's a lot of complexity in a foot.

This has to be a solved problem unless the womb offers some sort of telemetry.

[deleted]

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

#25
post #11
post #5

Earlier quoted context omitted.

if you got cancer, just cut that piece off and eat more?

Yeah, just regrow that brain, liver, thyroid gland. It could be those genes raise chance of cancer everywhere. Not just limbs.

I'd be willing to activate that feature if I was about to die.

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

#26
post #15
post #14

This is the type of research where I like to fantasize about the outcome. As a human race we've managed to basically cheat evolution with our advances in medicine and technology. If somehow we can stay alive as a species long enough we very well might be able to discover the secret to regeneration and immortality in some way.

> If somehow we can stay alive as a species long enough we very well might be able to discover the secret to regeneration and immortality in some way. Hopefully we won't figure that out before we figure out how to not overcrowd Earth.

Forbid procreation for those who chosen immortality. If you decided to spawn children, then free space for them - die. (Or go cryopreservation and be kept in a small box occupying little space. In this case you and your decedents can live in turns: they live for one century while you sleep frozen; next century other way around).

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

#27
post #20
post #2

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. A reasonable default assumption is that each switch in our "genetic configuration" is set to a quite good value. The only exception is if we see a feature that is beneficial at a high calorie cost - those features have been (reasonably) optimized away during our evolution, but would be use…

The ability to regenerate body parts and cancer are not inextricably linked. Take the axolotl. It has the ability to regenerate entire limbs. It's also estimated to be a couple orders of magnitude more resistant to cancer than humans.

Maybe that's the ticket? The cancer resistance is something that allows the axolotl to also keep regrowing limbs around in the genome?

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

#28
post #3
post #2

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. A reasonable default assumption is that each switch in our "genetic configuration" is set to a quite good value. The only exception is if we see a feature that is beneficial at a high calorie cost - those features have been (reasonably) optimized away during our evolution, but would be use…

And perhaps some people might risk the chance of cancer to grow their body parts back.

Perhaps it could be turned on and off as needed: lose a finger in an accident, and take a drug to turn regeneration on. Grow your finger back in a week, and then take another drug (or stop taking the first drug) to go back to normal.

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

#29

I'm a huge believer that humans can cherry-pick the best traits of many different species and apply them to ourselves. It might sound like science fiction right now, bit give it time and we humans will have unlocked some crazy things that we claimed to be "impossible." It's always impossible until it's done. And to be honest, I think the second something is thought of, it becomes possible. I live for this shit.

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.

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

#30
post #2

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. A reasonable default assumption is that each switch in our "genetic configuration" is set to a quite good value. The only exception is if we see a feature that is beneficial at a high calorie cost - those features have been (reasonably) optimized away during our evolution, but would be use…

> A reasonable default assumption is that each switch in our "genetic configuration" is set to a quite good value.

I'd question that assumption-- each switch in our "genetic configuration" is set to a value, and it's set to one that results in survival often enough for the species to reproduce, but it's not necessarily the optimal value, or even a particularly good one. It's just one that happened to be able to survive under environmental pressures at some particular time.

To put this into a computer science context, genetic algorithms have the same problem-- they can find local maxima easily, but can have difficulty (depending on the nature of the search space) locating global maxima because they can't sacrifice short-term fitness to gain long-term fitness.

Post reply on HN