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Scientists Discover New Clues To Regeneration: How Flatworms Regrow Heads

samzenpus posted 1 year,6 days | from the two-heads-are-better-than-none dept.

Science 76

An anonymous reader writes "Regeneration is one of the most useful skills that an organism can possess. Lizards can regrow their tails and starfish can regrow and entire part of themselves if they're cut to pieces. Yet scientists have long wondered why some creatures possess this ability while others don't. That's why they decided to examine the process of regeneration, looking at the masters of this particular adaptation: flatworms."

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76 comments

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Meanwhile, Slashdot ters Still Unsure How to Spell (-1)

Anonymous Coward | 1 year,6 days | (#44384491)

"Lizards can regrow their tails and starfish can regrow and entire part of themselves if they're cut to pieces."

Re: Meanwhile, Slashdot ters Still Unsure How to S (1)

Anonymous Coward | 1 year,6 days | (#44384961)

That's grammar; not spelling.

Re: Meanwhile, Slashdot ters Still Unsure How to S (1)

FrankSchwab (675585) | 1 year,6 days | (#44385301)

Not if the intention was to write "..regrow an entire...". A typo that comes out as a real word that makes the grammar wrong is still a typo ( a spelling error).

If you're going to be a Grammar Nazi on a Spelling Nazi's post, you should at least make sure that you're right.

A typo isn't the same as a spelling error. (0)

Anonymous Coward | 1 year,6 days | (#44385691)

A typo isn't a spelling error. A typo - typographical error - is when the wrong key is pressed, typically one that's adjacent to the intended letter. Spelling the word "separate" as "seperate" is a spelling error. Spelling it as "selerate" is a typo. I agree fully with your last sentence.

Re: Meanwhile, Slashdot ters Still Unsure How to S (1)

osu-neko (2604) | 1 year,6 days | (#44385701)

Not if the intention was to write "..regrow an entire...". A typo that comes out as a real word that makes the grammar wrong is still a typo ( a spelling error).

Heh. Since everyone is being pedantic today... not all typos are spelling errors. :p

Re: Meanwhile, Slashdot ters Still Unsure How to S (0)

Anonymous Coward | 1 year,6 days | (#44390107)

...you should at least make sure that you're right.

*your

(yes I'm joking.)

Re: Meanwhile, Slashdot ters Still Unsure How to S (1)

camperdave (969942) | 1 year,6 days | (#44385307)

That's grammar; not spelling.

Grammar is spelling at the sentence level.

Re: Meanwhile, Slashdot ters Still Unsure How to S (1)

K. S. Kyosuke (729550) | 1 year,6 days | (#44385847)

I'd say that it's more like "grammar is morphology on the sentence level".

Re: Meanwhile, Slashdot ters Still Unsure How to S (0)

Anonymous Coward | 1 year,6 days | (#44387195)

Noam Chomsky is coming to kill you because of that.

Re:Meanwhile, Slashdot ters Still Unsure How to Sp (1)

arth1 (260657) | 1 year,6 days | (#44385517)

Also, from TFA:

"Flatworms--more specifically, Schmidtea mediterranea--possess the amazing ability to regenerate. Even if the worm is cut into 200 pieces, 200 new worms will regenerate from each and every piece. "

No, I really don't think you get 40,000 worms.

Re:Meanwhile, Slashdot ters Still Unsure How to Sp (0)

Anonymous Coward | 1 year,6 days | (#44389145)

Ambiguous sentence structure...

It should have been written "each and every piece will regenerate into new worms"

Re:Meanwhile, Slashdot ters Still Unsure How to Sp (0)

Anonymous Coward | 1 year,6 days | (#44385523)

If you were granted an uninterrupted spree of ten thousand days of posts correcting English usage on slashdot, do you imagine that on day ten thousand and one there would be even one less mistake then when you began? Yes you do, you actually imagine that somehow you are making a difference. The reality is you are polluting the comments section, wasting everyone's time. Either contribute to the topic or go away.

Re:Meanwhile, Slashdot ters Still Unsure How to Sp (1, Funny)

Anonymous Coward | 1 year,6 days | (#44386339)

"If you were granted an uninterrupted spree of ten thousand days of posts correcting English usage on slashdot, do you imagine that on day ten thousand and one there would be even one less mistake then when you began?"

It's 'than', not 'then'.

uh huh (3, Funny)

MickyTheIdiot (1032226) | 1 year,6 days | (#44384499)

Matt Smith is pleased.

Re:uh huh (1)

K. S. Kyosuke (729550) | 1 year,6 days | (#44384705)

Matt Smith is pleased.

And so is Leonard Betts.

Re:uh huh (1)

Beorytis (1014777) | 1 year,6 days | (#44385739)

His hair was going to grow back anyway...

"Regeneration is one of the most useful skills" (2)

Joining Yet Again (2992179) | 1 year,6 days | (#44384511)

really? Cool, certainly, but it seems there hasn't been a need to evolve the skill in many species.

Re:"Regeneration is one of the most useful skills" (2)

Nrrqshrr (1879148) | 1 year,6 days | (#44384593)

Well, evolution at work, I guess. if you'r stupid enough to lose your head, you probably shouldn't regrow it.

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44384755)

I just wish i could grow myself a better head. This one sucks.

Re:"Regeneration is one of the most useful skills" (1)

SJHillman (1966756) | 1 year,6 days | (#44384871)

So that's the logic behind Highlander...

they don't Regeneration hand or other parts no hea (1)

Joe_Dragon (2206452) | 1 year,6 days | (#44384995)

they don't Regeneration hand or other parts no heads as well.

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44384619)

I guess you mean that there are species which don't regenerate, which could mean the ability reduced the species ability to reproduce overall, the ability provided no positive or negative effect on reproduction and genetic drift eliminated it at random, some gene showed up that was a net gain but deactivated regeneration, or that the species merely never acquired the ability. A species doesn't see another species walking around with a cool attribute and just say to itself, "That looks useful; I should try it out." (Except us, perhaps, but it's not the pattern of natural selection.)

Re:"Regeneration is one of the most useful skills" (2)

SJHillman (1966756) | 1 year,6 days | (#44384777)

I think he just picked a poor way of saying "if it was THAT useful, then we'd see regeneration-capable species outsurviving non-capable species". Since we don't see regeneration-capable species drastically outperforming non-capable species in the survival game, then it suggests that regeneration isn't the survival superpower that Wolverine would have us believe.

Or, as you said, he could just be anthropomorphizing evolution. Evolution hates when you do that.

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44385031)

My bet is that the ability to regenerate limbs reducing the overall lifespan of an organism due to the quantity of extra DNA needed to encode and provide for this ability. With a reduced lifespan, you get fewer chances to procreate and therefore it isn't necessarily a great trade-off. And, slashdotters should know, they get few chances if any to procreate.

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44386683)

Lobsters are long lived (over 100 years ins't uncommon) and regenerate quite well.

Re:"Regeneration is one of the most useful skills" (1)

SJHillman (1966756) | 1 year,6 days | (#44389565)

Some studies suggest that lobsters are effectively immortal and just keep growing larger and larger until they're killed by disease or predators, but generally never die of simple old age.

Re:"Regeneration is one of the most useful skills" (1)

ewibble (1655195) | 1 year,6 days | (#44387859)

Slightly of topic, but since you mentioned Wolverine.

I think death (old age) is a useful trait to have (most species have it, from a evolution stand point). It allows for change as new generations come in. If you never died there would be no intensive for reproduction, your offspring would simply consume your resources.

Re:"Regeneration is one of the most useful skills" (1)

John.Banister (1291556) | 1 year,5 days | (#44390661)

I think you've got the right idea, but I take a slightly different viewpoint. The impulse to reproduce exists without concern for thoughts of the future. After you instinctively reproduce, the species/evolution combo want the resources to go to your offspring rather than you. Once you enable them to survive well enough for them to reproduce, you fail to regenerate, age and die so that you don't consume their resources.

I think in order for a species of individuals that regenerate to successfully compete with one that does the - lots of reproduction with genetic mixing, survival of the fittest genetics - the individuals that regenerate will need to find a way to improve themselves. Otherwise they'll eventually fail at competition with future generations of the species that keeps improving its members the evolutionary way.

The wraith can regeneration real fast (1)

Joe_Dragon (2206452) | 1 year,6 days | (#44385175)

if they just fed on something.

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44384653)

really? Cool, certainly, but it seems there hasn't been a need to evolve the skill in many species.

What does one have to do with the other? Teleportation would be extremely useful, the fact that no species has achieved teleportation doesn't negate it's usefulness

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44384835)

I agree that it probably isn't one of the most useful skills, but be careful with your natural selection logic. Remember that evolutionary forces only cause organisms to react to factors that affect reproduction rates and in non-directly proportional relation to the size of the effect. So, for instance, if you have evolutionary forces A, B, and C that show up at different times, you're likely to select for solutions for each one as they come up, even if something like regeneration would be more "useful" and do almost as good of a job of solving A and immediately solving B and C. Also, not all mutations are equally likely.

Ergo, the number of species with a given trait is not necessarily a good metric for how useful that trait is.

Re:"Regeneration is one of the most useful skills" (1)

similar_name (1164087) | 1 year,6 days | (#44387823)

cause organisms to react to factors

All in all good, but this one set of words is incorrect. The organisms do not react at all. They vary and if selective pressure is high (ie a high mortality rate), then the species features will be redefined by the survivors. If aliens came to earth and decided to kill everyone except those with 6 fingers on their hands the human race would have 6 fingers on their hands.

Do it yourself experiment:

Take 100 dogs. Get them to stand on their back legs. Take the 10 that stand the longest. Breed them until you have a 100 dogs again. Repeat until you have dogs that are comfortable on 2 legs.

Or you can see in Soviet Russia fox turns to dog [youtube.com] .

Evolution & scarring (5, Interesting)

Valdrax (32670) | 1 year,6 days | (#44385183)

Actually, it's more like the skill was lost in favor of one that was considered far more useful for survival -- inflammation and scarring.

Scarring stops bleeding and infection far faster than regeneration can and is a vital advantage in quick and dirty wound recovery. Scarring comes about because of a mutation that allows collagen to cross-link and build quicker scaffolding to seal the wound, but it comes at the cost of not being able to regrow tissues in the now "paved over" area. In the wild, this gave our distant mammalian ancestors the valuable ability to just kind of "write-off" the area and get up and going as fast as possible and avoid being preyed upon in a moment of weakness.

We may dismiss scarring today as ugly and wasteful of an opportunity to be made whole again, but without it, we probably wouldn't exist today.

Re:Evolution & scarring (0)

Anonymous Coward | 1 year,6 days | (#44386287)

Error: Bad sector. Write around it.

Re:Evolution & scarring (1)

Thanshin (1188877) | 1 year,6 days | (#44388681)

"Scarring is OP!"

(Sometimes I think I may have liked being a teacher.)

(Sometimes I think how wonderful would school have been if my teacher had explained the world instead of just showing it.)

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44386377)

Amongst human beings the experiments that have succeeded have all been politicians...

Re:"Regeneration is one of the most useful skills" (0)

Anonymous Coward | 1 year,6 days | (#44386943)

Faggots don't evolve. They just die like the cock smokers that they are.

Paywall ugh (5, Insightful)

earlzdotnet (2788729) | 1 year,6 days | (#44384567)

Article is paywalled. I can get it on "readcube" for either $5 or $10. Or I can get it in a sane format (PDF) for $32. ORRR I can pay a lowly $200 to "subscribe to Nature" for some amount of time. And companies wonder why people pirate their material

Re:Paywall ugh (0)

Anonymous Coward | 1 year,6 days | (#44385085)

Because the majority of piracy isn't 99 cent songs or 5 dollar DVD movies, it's science journals! Riiiiight.

Re:Paywall ugh (1)

nurb432 (527695) | 1 year,6 days | (#44387277)

which most of the time are funded by tax dollars, at least in part.

Re:Paywall ugh (0)

Anonymous Coward | 1 year,6 days | (#44385387)

Have you tried simply having the internet 'regrow' the article?

which is the "real" starfish (3, Interesting)

callmebill (1917294) | 1 year,6 days | (#44384595)

Suppose you could cut a starfish into 5 segments, and they could each regenerate the missing 4. Which is the real one? How much of a body can one replace before it's a different body?

Re:which is the "real" starfish (1)

cusco (717999) | 1 year,6 days | (#44384677)

In the case of flatworms the second link (which plays a really annoying audio ad) says that some species can be cut into as many as 200 pieces and regrow into 200 new flatworms. IIRC, flatworms have a (fairly limited) ability to learn. I wonder if any of the regenerated worms maintain the learned behavior.

Re:which is the "real" starfish (4, Insightful)

camperdave (969942) | 1 year,6 days | (#44385649)

I wonder if any of the regenerated worms maintain the learned behavior.

Yes, they can [io9.com] .

Re:which is the "real" starfish (0)

Anonymous Coward | 1 year,6 days | (#44387935)

That. Is. Fucking. Awesome.

Re:which is the "real" starfish (1)

SJHillman (1966756) | 1 year,6 days | (#44384807)

An old thought experiment, I've heard it most repeated with cars, as well as by George Carlin. If you have a car and you replace a bolt, is it still the same car? Most people would say yes. What if you replaced another bolt? Most would still say yes. What if you replace every single part, one at a time? What if you then took all of those original parts and reassembled them into a new car. Which is the original?

Personally, I'd say none of your starfish are the "original" unless there's a core piece that you can point to and say that's what defines a starfish. The others would have to create a new core piece, and thus are no longer the original. If there is no core piece to make that individual unique, then all five are clones of the original.

Re:which is the "real" starfish (3, Informative)

Anonymous Coward | 1 year,6 days | (#44385403)

The original conception was not cars, but the Ship of Theseus. [wikipedia.org]

It's mostly about how we define identity and doesn't really have an answer.

Re:which is the "real" starfish (2)

osu-neko (2604) | 1 year,6 days | (#44386063)

The original conception was not cars, but the Ship of Theseus. [wikipedia.org]

It's mostly about how we define identity and doesn't really have an answer.

It has an answer, just not one most people are looking for. If you want to know which ship is Theseus' ship, go ask the Athenian Port Authority. Property is a legal concept, and they're the authorities -- they can give you the definitive answer, and can't possibly be wrong, because they determine the right answer by virtue of their authority and what it means for it to be "his" ship.

(Despite what it looks like, this is not actually dodging the question. Rather, it's making a point about it. Property is a "legal fiction", it's an abstraction of a particular sort. Identity is also an abstraction... people are only flustered by the Ship of Theseus if they mistakenly think otherwise.)

Re:which is the "real" starfish (0)

Anonymous Coward | 1 year,6 days | (#44386695)

If I restate the Ship of Theseus in slightly different terms, is it still the Ship of Theseus?

Re:which is the "real" starfish (1)

osu-neko (2604) | 1 year,6 days | (#44385759)

Suppose you could cut a starfish into 5 segments, and they could each regenerate the missing 4. Which is the real one?

Huh? They're all real. You don't end up with one real and four imaginary starfish.

How much of a body can one replace before it's a different body?

Your body is different today than it was yesterday. Life is change...

Flatworms? (2)

TheCarp (96830) | 1 year,6 days | (#44384623)

Please. Flatworms are great but plants.... plants are the champions here. Cut them off at the base, and they regrow from their roots. Cut off a branch and keep it from drying out, and it will regrow roots. Cut off leaves, it grows more, cut branches, it grows more.

Cut a flatworm up, you get more of the same. Cut a plant, and it will not just regrow....it will actually grow more limbs than you cut off. Wake me up when you cut a lizards tail off and he grows 6 more tails in response.

Re:Flatworms? (0)

Anonymous Coward | 1 year,6 days | (#44384699)

Please. Flatworms are great but plants.... plants are the champions here. Cut them off at the base, and they regrow from their roots. Cut off a branch and keep it from drying out, and it will regrow roots. Cut off leaves, it grows more, cut branches, it grows more.

Cut a flatworm up, you get more of the same. Cut a plant, and it will not just regrow....it will actually grow more limbs than you cut off. Wake me up when you cut a lizards tail off and he grows 6 more tails in response.

Actually lizards do sometimes grow a double or triple tail when they regenerate a lost one.

Re:Flatworms? (1)

SJHillman (1966756) | 1 year,6 days | (#44384857)

The difference is whether we can apply it to us. Flatworms are at least in the animalia kingdom, so it's a big step closer to being useful for humans compared to plantae.

Re:Flatworms? (1)

snadrus (930168) | 1 year,6 days | (#44385333)

Regeneration was found in some mice last year. Mammals is an even closer subgroup.

6 more tails (1)

dutchwhizzman (817898) | 1 year,6 days | (#44385093)

6 more tails wouldn't be functional, so it regrows only one, often just partially and only if the lizard species possesses the capability at all. Most species that do, often have a limited capability to regrow the tail more than once. A lizard needs it's tail to balance itself during running and climbing and more than one would hinder it.

Re:Flatworms? (1)

camperdave (969942) | 1 year,6 days | (#44385603)

Wake me up when you cut a lizards tail off and he grows 6 more tails in response.

I've heard of one where if you cut off its head, another two would grow in its place.

Re:Flatworms? (1)

LongearedBat (1665481) | 1 year,6 days | (#44388287)

....known as a hydra.

Re:Flatworms? (1)

nospam007 (722110) | 1 year,6 days | (#44386369)

"Cut a flatworm up, you get more of the same. Cut a plant, and it will not just regrow....it will actually grow more limbs than you cut off."

That's exactly the reason, why it was switched off in higher organisms, they can't handle the extra limbs.

Re:Flatworms? (1)

Walruzoar (514362) | 1 year,6 days | (#44389129)

Please don't tell the zombies about this.
We'll never be able to stop them!

New head (4, Funny)

Sponge Bath (413667) | 1 year,6 days | (#44384681)

Maybe John Wayne Bobbitt could benefit?

Re:New head (0)

Anonymous Coward | 1 year,6 days | (#44384709)

Wow, that reference is older than your user id number!

Re:New head (1)

Sarius64 (880298) | 1 year,6 days | (#44385195)

He only takes tips!

Useful for kaiju (1)

jphamlore (1996436) | 1 year,6 days | (#44385187)

Regrowing body parts or even growing new ones is certainly useful for kaiju.

You i8sensitive clod? (-1)

Anonymous Coward | 1 year,6 days | (#44385275)

th54t the project

Reminds me of a starfish story (1)

Solandri (704621) | 1 year,6 days | (#44385303)

Some city was suffering from reduced tourism because their beaches had been invaded by starfish. So they paid some kids to go to the beach and kill every starfish they found by cutting it in half...

What a way to cure a hangover (2)

Alain Williams (2972) | 1 year,6 days | (#44385453)

Cut off your head & grow a new one. Cool!

So can my cut-off finger grow a new me? (0)

Anonymous Coward | 1 year,6 days | (#44385659)

Exactly what defines the "self" vs. the "piece"? If you have a way to keep the piece alive, can it become a new self?

Re:So can my cut-off finger grow a new me? (1)

osu-neko (2604) | 1 year,6 days | (#44386113)

Exactly what defines the "self" vs. the "piece"?

You do.

If you have a way to keep the piece alive, can it become a new self?

In the same sense that any bit of everything can itself be considered its self, sure.

Re:So can my cut-off finger grow a new me? (0)

Anonymous Coward | 1 year,6 days | (#44388193)

Actually with the research being done with this they sort of asked exactly that question, although in the form of "but does the new body retain the memories of the old body before the brain was cut off".

Turns out it does to one specific extent, they isolated a bunch of the flatworms such that they had to reach their food a certain way. They then cut off their heads and waited for them to regrow.

They then watched to see if the cut off head worms retained the training and it turned out they did, compared with flatworms that hadnt had to seek their food by that method the regrown head ones were much more proficient at reaching the food sources still.

Messed up stuff.

Excellent... (1)

Kazoo the Clown (644526) | 1 year,6 days | (#44385835)

This could be useful, I know quite a few politicians that need to grow new heada...

Hell, just transplant my head (1)

Impy the Impiuos Imp (442658) | 1 year,6 days | (#44386379)

I want new feet. I want a new right arm. I want a new penis. I want new teeth.

Not necessarily in that order.

If you .. (0)

Anonymous Coward | 1 year,6 days | (#44386469)

If you cut off my head, is it me and my head or me and my body?

Cut a starfish exactly in half.. (0)

Anonymous Coward | 1 year,6 days | (#44387563)

When they regrow, are they then clones?
If so, which one is the clonee and which one is the original?

helps out the BBC (1)

rossdee (243626) | 1 year,6 days | (#44388471)

So this gets around the 12 regeneration limit for Time Lords?

John Hurt is not going to be the last Doctor

Re:helps out the BBC (0)

Anonymous Coward | 1 year,6 days | (#44389185)

There is always the Doctors Daughter...

Really a mystery? (0)

Anonymous Coward | 1 year,6 days | (#44388953)

"Yet scientists have long wondered why some creatures possess this ability while others don't."

Really? Are scientists that stupid? More complex organisms can't do it that easily and they probably also don't need it. Well of course: for the people in the U.S. natural selection is just a "faith" of the minorities.

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