Live data from Hacker News

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

washington.edu

81–90 of 167 posts

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

#81

The "we have the same genes" argument is completely absurd. So alright, some set of DNA sequences in the context of a worm enable the regeneration of worm parts; does it follow that the same set of DNA sequences in the context of a human enable the regeneration of human parts? Of course not! In the same way that the knowledge of how fix a bike has little bearing on being able to fix a cellphone, or that the touchscre…

> does it follow that the same set of DNA sequences in the context of a human enable the regeneration of human parts? Of course not!

But that isn't really the argument. We know we can grow limbs because we've all done it once before.

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

#82
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.

At some point in our evolutionary history the cells in our body made this choice. Evolution favors survival and potentially reproduction, because otherwise you are no longer in the game. So there was some evolutionary constraint that caused those genes not to regenerate parts.

It's possible we can change things so that those genes are active again. But we don't really understand these systems well enough to do that and won't anytime soon. But science carries on and I am sure you can make lab mice to test hypotheses of how this might work in mammals. And we probably will very soon, if not here then in China.

Evolution is perfectly fine even if you don't reproduce much, as long as you continue to survive in your environment. There are creatures out there that have changed very little and we know this because we have fossil records, and this is because they have been adapted to their environment and stayed adapted despite the environmental changes. And there are even immortal creature that die not because their bodies age and kill them but because they are eaten by other things, but still they don't change much over time. I guess you could say they are better evolved than other creatures that have to constantly change. They made better evolutionary decisions than other creatures very early on.

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

#83
post #63

Few years back I remember reading a story about the guy who lost his finger in an accident and then regrew it by dipping it into some kind of a powder. Edit: found it! > The magical formula to regrow a finger apparently includes a doctor, a pig, and some “pixie dust.” This is no fairytale, though; this is a medical breakthrough being explored at the University of Pittsburgh, Pa. In Science Channel’s video, “How to Gr…

> In Science Channel’s video, “How to Grow a New Fingertip”

Just wow! This story is about actually regrowing a finger on the man's hand.

It's so incredible, I'd skeptical. Is this really correct? Why didn't they make a time lapse video of the man's finger regrowing -- even taking just one photo per day. That would have been the obvious thing to do, but they didn't do it (or didn't show it).

UPDATE: On further research, I guess it was just too good to be true. Here's one rebuttal to the claims from the exuberant video:

https://www.theguardian.com/science/2008/may/01/finger.claim

tl;dr: The finger was not so badly injured. It healed rather than regrew.

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

#84
post #53

"Why can't we break off half a microchip, and then rebuild the missing part so it works again? We have all the mask artwork and silicon wafers ..."

This doesn't strike me as a reasonable analogy. 1) Microchips don't grow autonomously in the first place, unlike organisms. 2) The article's point is that not only do humans have the "mask artwork and silicon wafers", but also the genes that other organisms use to regenerate portions of their body. A closer equivalence would be "the instructions on how to rebuild the missing half of the microchip from what remains".

Microchips grow autonomously if you regard the entire fab and its staff as a big organism.

And note that the blueprints for the chip do actually encode more or less what it looks like: as a genotype they resemble the phenotype. Yet such a repair is not feasible.

DNA genes do not encode an arm or a leg directly, but a convoluted process by which the structure develops.

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

#85

The "we have the same genes" argument is completely absurd. So alright, some set of DNA sequences in the context of a worm enable the regeneration of worm parts; does it follow that the same set of DNA sequences in the context of a human enable the regeneration of human parts? Of course not! In the same way that the knowledge of how fix a bike has little bearing on being able to fix a cellphone, or that the touchscre…

> does it follow that the same set of DNA sequences in the context of a human enable the regeneration of human parts? Of course not! But that isn't really the argument. We know we can grow limbs because we've all done it once before.

I boned toad today.

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

#86

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.

Whoever down voted this is boring.

or they don't like spiderman

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

#87
post #82
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. At some point in our evolutionary history the cells in our body made this choice. Evolution favors survival and potentially reproduction, because otherwise you are no longer in the game. So there was some evolutionary constraint that caused those genes not to regenerate parts. It's possible we can change things so that those genes are acti…

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.

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

#88
We regenerate plenty. Our bodies are constantly regenerating. We keep growing new skin to replace old (dandruff is a simple example), damaged organs can recover (eg liver problems), and even exercising to increase strength involves regeneration (broken muscle fibres grow back stronger). We don't regenerate large external body parts in general, but we do regenerate some bits quite well - like the palms of our hands.

If you cut us, do we not bleed? Then clot? Then grow new tissue to heal the wound? Sometimes so that there is no evidence of a cut afterwards?

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

#89
post #63

Few years back I remember reading a story about the guy who lost his finger in an accident and then regrew it by dipping it into some kind of a powder. Edit: found it! > The magical formula to regrow a finger apparently includes a doctor, a pig, and some “pixie dust.” This is no fairytale, though; this is a medical breakthrough being explored at the University of Pittsburgh, Pa. In Science Channel’s video, “How to Gr…

> In Science Channel’s video, “How to Grow a New Fingertip” Just wow! This story is about actually regrowing a finger on the man's hand. It's so incredible, I'd skeptical. Is this really correct? Why didn't they make a time lapse video of the man's finger regrowing -- even taking just one photo per day. That would have been the obvious thing to do, but they didn't do it (or didn't show it). UPDATE: On further researc…

Here's some pictures of finger regeneration. DO NOT open these images if medical imagery bothers you. They're gruesome :)

http://www.mebo-international.com/sites/default/files/field/...

Page with a lot more pictures:

http://www.mebo.com/a/books/HUMAN/2011/0221/2934.html

These examples are from stem-cell activation therapy:

http://www.space-age.com/fingertipregeneration.html

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

#90
post #82

Earlier quoted context omitted.

> Evolution evolved to ensure the survival of the species, not the individual. At some point in our evolutionary history the cells in our body made this choice. Evolution favors survival and potentially reproduction, because otherwise you are no longer in the game. So there was some evolutionary constraint that caused those genes not to regenerate parts. It's possible we can change things so that those genes are acti…

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.
Post reply on HN