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Zebrafish Regenerative Ability May Lead To Help In Humans

Soulskill posted more than 6 years ago | from the incredible-edible-zebrafish dept.

Medicine 106

esocid tips us to news out of Duke University Medical Center, where researchers have discovered a type of microRNA that is related to the ability of zebrafish to regenerate lost or damaged organs. This is the result of a study initiated after it was discovered that zebrafish were able to recover from "massive injury" to the heart through their own regenerative biology. The scientists hope to be able to use this information to bring about similar healing in humans. Zebrafish have also been helpful in cancer research. "In zebrafish, one or more microRNAs appear to be important to keep regeneration on hold until the fish needs new tissue, the Duke researchers say. In response to an injury, the fish then damp down levels of these microRNAs to aid regrowth. Poss and many other cell biologists believe that mammals may have the same tissue regeneration capability as zebrafish, salamanders and newts, but that it is locked away somewhere in our genome, silenced in the course of evolution."

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heh (5, Funny)

ionix5891 (1228718) | more than 6 years ago | (#22765634)

if i had a tail i'll play with it all day...

Re:heh (5, Funny)

CRCulver (715279) | more than 6 years ago | (#22765648)

If you know the etymology of Latin "penis", then your comment ends up saying something more than you probably intended.

Re:heh (0)

Anonymous Coward | more than 6 years ago | (#22765828)

If you know the etymology of latin "penitus invidia", then your comment ends up saying something more about your ATI ownership than you probably intended.

In case you didn't get it (2, Informative)

pxc (938367) | more than 6 years ago | (#22766316)

penis
1676, perhaps from Fr. pénis or directly from L. penis "penis," earlier "tail" (cf. Eng. tail in both senses, the sexual one slang), from PIE *pes-/*pesos- "penis" (cf. Skt. pasas-, Gk. peos, posthe "penis," probably also O.E. fæsl "progeny, offspring," O.N. fösull, Ger. Fasel "young of animals, brood"). The proper plural is penes. The adj. is penial. In psychological writing, penis envy is attested from 1924.
http://www.etymonline.com/index.php?term=penis

Re:In case you didn't get it (1)

layer3switch (783864) | more than 6 years ago | (#22769530)

The proper plural is penes.

It's one thing to know more than I can understand, but now I've learnt this, I'm just confused to where and when to apply this knowledge.

Re:In case you didn't get it (0)

Anonymous Coward | more than 6 years ago | (#22772418)

A nontraditional twist on classic penis insults:
"I'd still be more of a man than you if you had two penes!"

Accusations of perversion against a large group:
"Get your minds off your penes, you perverts!"

A variation of the penis game:
Rather than shouting penis, simply sing "99 preserved penes on the wall" progressively louder

And of course, the infamous "this isn't my finger":
"These aren't my fingers."
"What the hell?"
"They're my _penes_."

Okay, maybe you're right. Any other ideas?

Re:heh (0)

Anonymous Coward | more than 6 years ago | (#22766534)

So what does it mean if a girl has a tail and you play with it?

Re:heh (1, Funny)

Anonymous Coward | more than 6 years ago | (#22766918)

It means you're a furry.

Freak! >:(

Re:heh (1)

neomunk (913773) | more than 6 years ago | (#22767514)

That "she" is pre-op?

Can we grow our heads back? (1, Informative)

CRCulver (715279) | more than 6 years ago | (#22765638)

This reminds me of that godawful late Beowulf Shaeffer story by Larry Niven "Procrustes" (collected in Crashlander [amazon.com] ) where someone loses their head and an autodoc manages to grow one back. I mention this not hoping anyone would go read the story, but to provide a forum where other people who lost hours of their lives to late Niven can express their feelings and frustrations to a sympathic audience of people who did the same.

Re:Can we grow our heads back? (2, Interesting)

foobsr (693224) | more than 6 years ago | (#22766042)

where someone loses their head and an autodoc manages to grow one back

Hmm ...

Quote: "But they got him into the autodoc anyway. It was a puppeteer-shaped coffin, form-fitted to Nessus himself, and bulky Puppeteer surgeons and mechanics must have intended that it should handle any conceivable circumstance. But had they thought of decapitation?

They had. There were two heads in there, and two more with necks attached, and enough organs and body parts to make several complete puppeteers. Grown from Nessus himself, probably; the faces on the heads looked familiar.
From Ringworld, by Larry Niven."

CC.

Re:Can we grow our heads back? (3, Informative)

CRCulver (715279) | more than 6 years ago | (#22766080)

With Puppeteers it's slightly more "believable", because a Puppeteer's brain is under its back. The "heads" hold only the eyes and the mouth, as well as serving to manipulate objects like hands.

Re:Can we grow our heads back? (3, Informative)

Ambitwistor (1041236) | more than 6 years ago | (#22766410)

The autodoc didn't grow his head back. It grew his body back, starting from only a head.

Great so instead of dying from liver sclerosis (1)

Timesprout (579035) | more than 6 years ago | (#22765644)

after all my drinking sessions I now get a healthy liver and then get eaten by a lion.

Re:Great so instead of dying from liver sclerosis (1)

arivanov (12034) | more than 6 years ago | (#22765700)

That and walking at an angle based on your social rank. I do not have zebrafish nowdays, but IIRC they swim at different angles with the ones on the bottom of the society ladder at the steepest angle and the dominant one in the tank swimming nearly horisontally.

Re:Great so instead of dying from liver sclerosis (1)

FooAtWFU (699187) | more than 6 years ago | (#22765768)

Could be worse. Instead of zebrafish, you could have a bananafish problem [wikipedia.org] .

Re:Great so instead of dying from liver sclerosis (0)

Anonymous Coward | more than 6 years ago | (#22766114)

OH shit a lion get in the car!!!!!

Re:Great so instead of dying from liver sclerosis (1)

jcuervo (715139) | more than 6 years ago | (#22767032)

We looked in the car, and there's the fucking king of the jungle! I almost shit my pants!

They Turned Me Into A NEWT!!! (1)

Skeetskeetskeet (906997) | more than 6 years ago | (#22765694)

I got better.....

wouldn't get my hopes up (4, Insightful)

nguy (1207026) | more than 6 years ago | (#22765708)

Human life expectancy is quite long by animal standards, so it seems like we probably just don't need this anymore. On the other hand, there are usually tradeoffs with these kinds of mechanisms, and turning it on again may have rather negative side-effects.

Re:wouldn't get my hopes up (4, Interesting)

gravesb (967413) | more than 6 years ago | (#22765730)

Exactly. There must be some evolutionary reason to turn it off, as it seems that this gene, in and of itself, would lead to sturdier off-spring, and thus propagate. It would be interesting to know why it got turned off, though. Rampant cancer, maybe?

Homeotherms (5, Interesting)

overshoot (39700) | more than 6 years ago | (#22765792)

Rampant cancer, maybe?

That would be my guess. There's a good bit of research where they tinkered with mouse genes to accelerate or slow telomere erosion, and found that the natural mouse is pretty close to the maximum lifespan possible. Faster erosion causes the mice die of old age sooner, but slower erosion results in more cancer deaths.

Regeneration may well have similar costs. Since all of the natural regenerators are poikilotherms, I would speculate that their overall lower metabolic rate has less risk of cancer. Giving up regeneration may well be the price we pay for warm blood.

Re:Homeotherms (5, Insightful)

ScrewMaster (602015) | more than 6 years ago | (#22765830)

True, but on the other hand, if we are able to reactivate an ancient yet problematic self-repair mechanism, there remains the possibility that we might fix it. Evolution doesn't guarantee optimal solutions by any means.

Re:Homeotherms (4, Funny)

11223 (201561) | more than 6 years ago | (#22767320)

Yeah, I saw that episode of SG: Atlantis. It never ends well.

Re:Homeotherms (1)

ScrewMaster (602015) | more than 6 years ago | (#22767498)

Mainly because Dr. Weir is incompetent.

Re:Homeotherms (1)

Richard.Tao (1150683) | more than 6 years ago | (#22767428)

Exactly. Just because it wasn't evolutionary adaptive at the time doesn't mean it isn't helpful now. Our environment has changed quite a bit since we our genetics (supposedly) found it more adaptive to turn the trait off. And if we can activate it in the right situation, we're set.

Re:Homeotherms (1)

nguy (1207026) | more than 6 years ago | (#22767998)

It's not clear to me how extending life far beyond the reproductive age is any more adaptive today than it was 50000 years ago. Even healthy folks rarely reproduce past 40, and rarely contribute productively past 70. You may not want to die or grow old, but from the point of view of adaptation, a life span of 70 years may still be optimal.

Re:Homeotherms (1)

amRadioHed (463061) | more than 6 years ago | (#22769708)

It doesn't matter. The moment humans began to care for other members of their society survival of the fittest no long applied. What we want is far more relevant than what is evolutionarily beneficial to our species.

Re:Homeotherms (1)

ultranova (717540) | more than 6 years ago | (#22775968)

The moment humans began to care for other members of their society survival of the fittest no long applied.

Incorrect. What actually happened is that the definition of "fit" began including getting people to like you more than it did previously.

"Survival of the fittest" is an oxymoron and therefore always true, so long as something survives, because the definition of "fit" is "that which survives", so the saying translates to: "Survival of that which survives". The only set of circumstances in which it would not be true would be total annihilation of all life; and even then you could argue that none was fit.

Re:Homeotherms (1)

Wonko the Sane (25252) | more than 6 years ago | (#22766046)

Probably the best bet is to turn it on temporarily in a limited location.

Re:Homeotherms (1)

ScrewMaster (602015) | more than 6 years ago | (#22766066)

That's usually the way it's done in most science-fiction stories, anyway. Does make the most sense, although it would be cool to be like the guy that instantly regenerates in the movie Silent Rage. Well ... minus the murderous psychopathy, anyway.

Re:Homeotherms (1)

PieceofLavalamp (1244192) | more than 6 years ago | (#22767162)

Yes there may be trade offs that doesn't reduce its worth. If its die from wounds now or cancer later i'd be okay with cancer later.

Re:Homeotherms (1)

amRadioHed (463061) | more than 6 years ago | (#22769866)

To me that would all depend on how painful the cancer and how much later it happens.

Re:wouldn't get my hopes up (4, Insightful)

nguy (1207026) | more than 6 years ago | (#22765822)

Cancer is a likely risk. I doubt it's rampant, though; just enough to make it problematic.

There is one ray of hope: some of these genes may have been turned off not because they are harmful, but because they use energy and have been made largely redundant. If you have good eyes and a good brain, for example, you are less prone to injury. Since energy isn't a problem anymore, reenabling these genes may make you both slim and healthy. It's a possibility, but I still wouldn't get my hopes up...

Re:wouldn't get my hopes up (1)

Takichi (1053302) | more than 6 years ago | (#22766632)

I dunno. From what I've learned, you can't give reason to evolution. Perhaps there was a different characteristic that provided better fitness to an individual, but that same individual lacked proper regenerative capabilities. No real reason for it to happen, it just did.

Re:wouldn't get my hopes up (1)

TheRaven64 (641858) | more than 6 years ago | (#22767100)

Evolution does not produce optimal individuals, it produces optimal[1] populations. It is against the interests of a species (from an evolutionary perspective) for individuals to live forever. If individuals live forever there is no evolution of the species because there is no change. If there is no change, then environmental changes can cause the extinction of the species.

Even if the self-repair has no side effects then it will likely lead to extinction of the species if it doesn't have the intelligence and technology to modify itself. Producing sturdier offspring is not a good thing in this case, because the parent, by not dying, will compete directly with its own offspring. Eventually, they will consume all of their available food and become extinct. Or they will recognise this, stop breeding, and die off when their environment changes.


[1] Locally optimal, anyway.

Re:wouldn't get my hopes up (1)

comradeeroid (1048432) | more than 6 years ago | (#22771768)

Well, there are a few things to take into consideration here. One is that procreation won't stop just because dying stops. Which will mean that there are still opportunities for the population to evolve.
The other on is that longer lifespans and regenerative abilities would definitely help us in the conquering of space, which is an evolutionary advantage compared to staying around here waiting for the next ELE to come around.
And since we as a species have the life expectancy of about (pulling random but plausible number out of hat) another 500 years or so (at best) unless we shape up signifcantly, we're not doing any natural evolution. Let's just kickstart all the genes we have and hope one of them does something usefull.

Re:wouldn't get my hopes up (0)

Anonymous Coward | more than 6 years ago | (#22767208)

"There must be some evolutionary reason to turn it off..."

Not necessarily. Evolution isn't survival of the fittest. It's survival of the good enough. If our ancestors had a mutation preventing regeneration, they'd do just as well by having more offspring, hiding better, being faster, being stronger, or just plain luckier.

Re:wouldn't get my hopes up (0)

Anonymous Coward | more than 6 years ago | (#22774300)

There must be some evolutionary reason to turn it off

Couldn't this have evolved recently in zebrafish? As in, why assume this gene existed in any other species, particularly ancestors of humans?

Re:wouldn't get my hopes up (1)

ScrewMaster (602015) | more than 6 years ago | (#22766036)

Well ... assuming this ability still exists in humans, and further assuming that we find a way to turn it on, there are situations where one might be willing to accept an increased risk of cancer or some other infirmity. I mean, suppose you were someone that had had his penis shot off: wouldn't you take the chance of a little cancer to get your rod back?

Re:wouldn't get my hopes up (0)

Anonymous Coward | more than 6 years ago | (#22767584)

The Darwin awards will NOT like this one bit.

Re:wouldn't get my hopes up (1)

ScrewMaster (602015) | more than 6 years ago | (#22767710)

Huh. Yeah, I hadn't thought of that.

Re:wouldn't get my hopes up (1)

nospam007 (722110) | more than 6 years ago | (#22768758)

I mean, suppose you were someone that had had his penis shot off: wouldn't you take the chance of a little cancer to get your rod back?

OMG, I already can imagine the spam:
Turn on regeneration in your penis, make it grow 5 inches, only 99$, minimal cancer risk, money back guaranteed.

Re:wouldn't get my hopes up (1)

Arancaytar (966377) | more than 6 years ago | (#22769830)

I'm pretty sure that a fair number of cancer patients would part with their organs in a second if it meant another thirty to forty years. Living without sex and peeing awkwardly may sound awful, but a slow death isn't so great either.

Re:wouldn't get my hopes up (1)

LaughingCoder (914424) | more than 6 years ago | (#22766444)

It seems likely that such a mechanism would be used mostly later in life ... after the reproductive years have passed. And so, evolution would not likely promote or demote this trait.

Re:wouldn't get my hopes up (1)

MichaelSmith (789609) | more than 6 years ago | (#22768128)

It seems likely that such a mechanism would be used mostly later in life ... after the reproductive years have passed. And so, evolution would not likely promote or demote this trait.

Grandparents help in the raising of their childrens children. I don't think being too old to reproduce isolates you from evolution. And how old would a man have to be to not become a parent?

Re:wouldn't get my hopes up (1)

pseudochaos (1014063) | more than 6 years ago | (#22770120)

Well right now the main detriment that aging brings to the table is cardiovascular health, so after a certain age (depending on the person) they're no longer healthy enough to have sex. I'm curious if regeneration would perhaps mitigate this factor, as cardiac cells could conceivably be regenerated to undo the effects of aging as well.

creators' planet/population rescue could use.... (0)

Anonymous Coward | more than 6 years ago | (#22765716)

some help from the so-called human race/man'kind'. it's not a requirement, but it could lead to yOUR survival. let yOUR conscience be yOUR guide. you can be more helpful than you might have imagined. there are still some choices. if they do not suit you, consider the likely results of continuing to follow the corepirate nazi hypenosys story LIEn, whereas anything of relevance is replaced almost instantly with pr ?firm? scriptdead mindphuking propaganda or 'celebrity' trivia 'foam'. meanwhile; don't forget to get a little more oxygen on yOUR brain, & look up in the sky from time to time, starting early in the day. there's lots going on up there.

http://news.yahoo.com/s/ap/20071229/ap_on_sc/ye_climate_records;_ylt=A0WTcVgednZHP2gB9wms0NUE [yahoo.com]
http://news.yahoo.com/s/afp/20080108/ts_alt_afp/ushealthfrancemortality;_ylt=A9G_RngbRIVHsYAAfCas0NUE [yahoo.com]
http://www.nytimes.com/2007/12/31/opinion/31mon1.html?em&ex=1199336400&en=c4b5414371631707&ei=5087%0A [nytimes.com]

is it time to get real yet? A LOT of energy is being squandered in attempts to keep US in the dark. in the end (give or take a few 1000 years), the creators will prevail (world without end, etc...), as it has always been. the process of gaining yOUR release from the current hostage situation may not be what you might think it is. butt of course, most of US don't know, or care what a precarious/fatal situation we're in. for example; the insidious attempts by the felonious corepirate nazi execrable to block the suns' light, interfering with a requirement (sunlight) for us to stay healthy/alive. it's likely not good for yOUR health/memories 'else they'd be bragging about it? we're intending for the whoreabully deceptive (they'll do ANYTHING for a bit more monIE/power) felons to give up/fail even further, in attempting to control the 'weather', as well as a # of other things/events.

http://video.google.com/videosearch?hl=en&q=video+cloud+spraying [google.com]

dictator style micro management has never worked (for very long). it's an illness. tie that with life0cidal aggression & softwar gangster style bullying, & what do we have? a greed/fear/ego based recipe for disaster. meanwhile, you can help to stop the bleeding (loss of life & limb);

http://www.cnn.com/2007/POLITICS/12/28/vermont.banning.bush.ap/index.html [cnn.com]

the bleeding must be stopped before any healing can begin. jailing a couple of corepirate nazi hired goons would send a clear message to the rest of the world from US. any truthful look at the 'scorecard' would reveal that we are a society in decline/deep doo-doo, despite all of the scriptdead pr ?firm? generated drum beating & flag waving propaganda that we are constantly bombarded with. is it time to get real yet? please consider carefully ALL of yOUR other 'options'. the creators will prevail. as it has always been.

corepirate nazi execrable costs outweigh benefits
(Score:-)mynuts won, the king is a fink)
by ourselves on everyday 24/7

as there are no benefits, just more&more death/debt & disruption. fortunately there's an 'army' of light bringers, coming yOUR way. the little ones/innocents must/will be protected. after the big flash, ALL of yOUR imaginary 'borders' may blur a bit? for each of the creators' innocents harmed in any way, there is a debt that must/will be repaid by you/us, as the perpetrators/minions of unprecedented evile, will not be available. 'vote' with (what's left in) yOUR wallet, & by your behaviors. help bring an end to unprecedented evile's manifestation through yOUR owned felonious corepirate nazi glowbull warmongering execrable. some of US should consider ourselves somewhat fortunate to be among those scheduled to survive after the big flash/implementation of the creators' wwwildly popular planet/population rescue initiative/mandate. it's right in the manual, 'world without end', etc.... as we all ?know?, change is inevitable, & denying/ignoring gravity, logic, morality, etc..., is only possible, on a temporary basis. concern about the course of events that will occur should the life0cidal execrable fail to be intervened upon is in order. 'do not be dismayed' (also from the manual). however, it's ok/recommended, to not attempt to live under/accept, fauxking nazi felon greed/fear/ego based pr ?firm? scriptdead mindphuking hypenosys.

consult with/trust in yOUR creators. providing more than enough of everything for everyone (without any distracting/spiritdead personal gain motives), whilst badtolling unprecedented evile, using an unlimited supply of newclear power, since/until forever. see you there?

"If my people, which are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land."

meanwhile, the life0cidal philistines continue on their path of death, debt, & disruption for most of US. gov. bush denies health care for the little ones;

http://www.cnn.com/2007/POLITICS/10/03/bush.veto/index.html [cnn.com]

whilst demanding/extorting billions to paint more targets on the bigger kids;

http://www.cnn.com/2007/POLITICS/12/12/bush.war.funding/index.html [cnn.com]

& pretending that it isn't happening here;

http://www.timesonline.co.uk/tol/news/world/us_and_americas/article3086937.ece [timesonline.co.uk]
all is not lost/forgotten/forgiven

(yOUR elected) president al gore (deciding not to wait for the much anticipated 'lonesome al answers yOUR questions' interview here on /.) continues to attempt to shed some light on yOUR foibles. talk about reverse polarity;

http://www.timesonline.co.uk/tol/news/environment/article3046116.ece [timesonline.co.uk]

Uh-huh (0)

Anonymous Coward | more than 6 years ago | (#22765718)

Riiiiiight, cause we all know our genome is soooo special... we will someday be able to coax our genetics to do aaaanything we want. I'm sure every single genetic possibility is locked away in our genome, silenced by evolution. I'm particularly interested in the "T-Rex gene". Let me know when we've found that one.

The unavoidable question is, (4, Insightful)

overshoot (39700) | more than 6 years ago | (#22765748)

... what is the evolutionary benefit that mammals get from not regenerating?

I'm reminded of a story from Analog in the 60s, where they figure out how to stimulate toot regeneration. Except that, once the technique has been in use for a while, they find out that it doesn't stop producing new teeth ...

Re:The unavoidable question is, (2, Interesting)

CRCulver (715279) | more than 6 years ago | (#22765772)

Interesting. In Gene Wolfe's novella Seven American Nights (collected in The Island of Doctor Death [amazon.com] ), the inhabitants of a post-apocalyptic America where some kind of nuclear radiation accident had occured repulse the narrator with their extra teeth. Perhaps your story in Analog is where Wolfe got the idea from?

This Slashdot story seems to be bringing up more associations with science fiction than usual.

Re:The unavoidable question is, (1)

hicksw (716194) | more than 6 years ago | (#22772744)

Like "End of Summer", by Algis Budrys, Astounding Science Fiction, November 1954?

A cure for cancer/death also cured long term memory.

Re:The unavoidable question is, (0)

Anonymous Coward | more than 6 years ago | (#22765860)

Less cancer

Re:The unavoidable question is, (0)

Anonymous Coward | more than 6 years ago | (#22765914)

Zebra danios? I always wondered why those little f***ers lived so long. Other fishies would jump out of the tank and be found later under my bed in a mummified state or float upside down in my tank, but those zebras never stopped darting around in the water like they were on a mission from God. Gotta love em.

Re:The unavoidable question is, (3, Insightful)

FatalChaos (911012) | more than 6 years ago | (#22766006)

Well one problem with regenerating is that it probably requires a LOT of energy, which would speed up metabolism a lot. Maybe our regenerating ancestors couldn't find enough food to support the feature, and plus if food is scarce and you are pooling a lot of energy to support this regeneration, this might lower your overall muscle mass or brain size, etc.

Re:The unavoidable question is, (0)

Anonymous Coward | more than 6 years ago | (#22767826)

Just what we need: "Amputate your leg diet"

Re:The unavoidable question is, (1)

happyemoticon (543015) | more than 6 years ago | (#22769748)

Perhaps there is something to the fact that, by and large, animals who can regenerate profoundly are cold-blooded, and no natural warm-blooded animals I'm aware of can do that. We already expend huge amounts of energy just keeping ourselves warm. Perhaps the regeneration faded with the increased energy expenditure from warm-bloodedness.

Re:The unavoidable question is, (1)

ScrewMaster (602015) | more than 6 years ago | (#22766104)

I'm reminded of a story from Analog in the 60s, where they figure out how to stimulate toot regeneration

Nothing special about that. I do it with pepperoni pizza all the time. Legumes also work well.

Re:The unavoidable question is, (5, Insightful)

vertinox (846076) | more than 6 years ago | (#22766450)

... what is the evolutionary benefit that mammals get from not regenerating?

Given the hostile everyday nature of the wild, an animal has a far better chance of surviving in the long run if he gets back on his feet after an injury even if it isn't a full one. Its far quicker for scar tissue to reform than it is to recreate all the tissue back in a perfect fashion.

So rather having an open wound for several weeks on on end, a wild mammal would have a scab within 24 hours and then later initial scar tissue within a week

Re:The unavoidable question is, (1)

Epistax (544591) | more than 6 years ago | (#22766730)

... what is the evolutionary benefit that mammals get from not regenerating?

Well, if the typical regeneration benefit would come to someone who is too old or otherwise too hurt to possibly be a parent, there's no way for a genetic advantage to pass along. I don't know if that's what's going on here.

Or conversely, perhaps the regeneration scheme has a better chance of screwing things up than that of a freak accident occurring. The opposite might be true for a zebra fish, thus it could develop.

I'm talking ottah my butt here, but it sounds good to me at the moment.

Re:The unavoidable question is, (1)

Translation Error (1176675) | more than 6 years ago | (#22766854)

The resources devoted to being able to regenerate could be used to avoid injury, instead. Even if you heal quickly and from grievous injuries, it's better not to get hurt in the first place--especially if the lack of regeneration means you're better able to avoid mishaps that would kill you instantly.

Re:The unavoidable question is, (1)

TheRaven64 (641858) | more than 6 years ago | (#22767150)

Evolution works on species, not on individuals. It doesn't select individuals likely to survive, it selects species. For evolution to work, it needs some random elements introduced into the genes regularly, which means it favours short-lived creates since they go through more evolutionary cycles in a given amount of time. If individuals live longer then competing species will become better adapted to their evolutionary niche. At this point the species dies out in most cases. Intelligence skews this since it means that adaptation is no longer a random process. Humans can adapt to their environments without changing their biology, which reduces the advantage of a short lifespan.

Re:The unavoidable question is, (2, Funny)

jdelisle (582839) | more than 6 years ago | (#22774240)

I'm reminded of a story from Analog in the 60s, where they figure out how to stimulate toot regeneration.
A can of beans, perhaps?

Lend me your ears (5, Funny)

pizzach (1011925) | more than 6 years ago | (#22765750)

AGH! I have ears regenerating all over my body! Get them off!

Re:Lend me your ears (1, Funny)

Anonymous Coward | more than 6 years ago | (#22765938)

>> AGH! I have ears regenerating all over my body! Get them off!

But please do it quietly!!

Why would regeneration ability be lost in mammals? (4, Interesting)

temcat (873475) | more than 6 years ago | (#22765758)

In my fairly limited understanding of evolution theory, the features that help to survive are retained through the natural selection. Regeneration ability seems to help to survive - why would it be lost then? Could it be that the time required to naturally regenerate was so long that the animal weakened by the injury died anyway by natural (lack of food and/or water access, climatic factors) or violent (predators) death?

Re:Why would regeneration ability be lost in mamma (1, Informative)

Anonymous Coward | more than 6 years ago | (#22765992)

It seems to me that regeneration ability might be closely related to uncontrolled cell growth and mutation - cancer. I'd bet that if we turn on the regeneration, we end up with more tumors growing on us too.

Trying to 2nd guess evolution probably isn't such a good idea.

Re:Why would regeneration ability be lost in mamma (1)

stephend (1735) | more than 6 years ago | (#22766054)

Evolution isn't really about survival into old age, more survival to an age where reproduction is possible -- just ask a male praying mantis. So one possible reason why regeneration abilities didn't survive is that it mainly benefits older animals who are less likely to be generating off-springs.

Re:Why would regeneration ability be lost in mamma (2, Informative)

OeLeWaPpErKe (412765) | more than 6 years ago | (#22766146)

The problem is cancer.

Regeneration is ... massive and nearly unlimited cell growth
Cancer is ... massive and unlimited cell growth

A tiny mistake in regeneration will therefore cause cancer very reliably, and quite deadly. In order to let people get really old, cancer must be prevented (most dogs could easily live up to 25, with reduced bodily function, instead of 15 without cancer, but they have more chance of recovering from large injuries during those 15 years).

There is another problem. Another very important reason human bodies don't regenerate is the immune system blocking the regeneration process. (you can prevent cuts from becoming scars with a large dose of aspirin and making sure the wound is not in contact with air (by making sure it's soaked in warm liquid for example)).

You can make regeneration easily very effective in humans ... just cut the immune system to a very low level, and disable a few cancer prevention mechanisms. Of course, make one tiny mistake, say 100 viral particles, and your patient probably won't survive.

Maximum age and regeneration are forces pushing in opposite directions. You can't have your cake and eat it, I guess. This research will, if it works, present a choice to people, a short, very robust life, or a long one where you'd probably best avoid any injuries. "Forever young" this is not.

Re:Why would regeneration ability be lost in mamma (4, Insightful)

ScrewMaster (602015) | more than 6 years ago | (#22766212)

"Forever young" this is not.

Maybe not ... but as another poster pointed out, if this capability were activated on a temporary basis solely for the purpose of regenerating lost or damaged tissue, it would prove invaluable. Hell, if this did become practical, one could chop out diseased parts of an organ and simply regenerate them. Transplants could become a thing of the past. Lose an extremity? Regrow it!

Re:Why would regeneration ability be lost in mamma (1)

OeLeWaPpErKe (412765) | more than 6 years ago | (#22766440)

And in the process turn any not-yet-cancerous warts into footballs ...

Re:Why would regeneration ability be lost in mamma (1)

amRadioHed (463061) | more than 6 years ago | (#22769892)

Maybe, or maybe not. At this point nobody knows what would happen.

Re:Why would regeneration ability be lost in mamma (1)

bar-agent (698856) | more than 6 years ago | (#22766538)

Mod parent up! It would be great to turn this off or on as needed.

That's apparently what the zebra fish do: the regen mechanism is dormant until they get injured and need to use it; then they "release control art restriction level" and allow the mechanism to work.

I'm guessing the mechanism either never evolved in mammals, or else something about our biochemistry means whatever chemicals the fish use to either inhibit or activate the mechanism become unstable, thus leading to uncontrolled regen and cancer.

Re:Why would regeneration ability be lost in mamma (1)

Frozen Void (831218) | more than 6 years ago | (#22766172)

Genome has interrelated genes, so turning regeneration on can be beneficial, but it also can turn on undesirable genes/RNA.Not necessary cancer but it may be something like 20% more susceptibility to malaria or something selected against in the far past.
it could be something which monkeys had problem with or entirely freak mutation which had more survival potential.
Its like the case with internal Vitamin C production which humans lack,but goats possess.

Re:Why would regeneration ability be lost in mamma (2, Insightful)

maxume (22995) | more than 6 years ago | (#22766288)

Evolution doesn't happen along cleanly defined lines; lots of people are trotting out cancer as an easy problem to relate to regeneration, but it doesn't need to be anywhere near that complex. It could be as simple as the developments leading to warm blooded metabolism accidentally turning off regeneration, so as those organisms took over niches where being exothermic was a big advantage, regeneration disappeared.

So the breakage of the regeneration mechanism could be completely incidental, even if was advantageous, if some species with broken regeneration evolved some other mechanism that conferred a larger advantage.

how it works (0)

Anonymous Coward | more than 6 years ago | (#22767134)

Could it be that the time required to naturally regenerate was so long that the animal weakened by the injury died anyway by natural (lack of food and/or water access, climatic factors) or violent (predators) death?
Of course; but that's just speculation, and we're limited to speculation in some sense. It helps to understand in detail the mechanisms of evolution: mutation and selection.

Evolution doesn't "converge" on optimal solutions/implementations; it diverges from existing implementations (through random mutation). New traits preserved by selection pressure can just as easily be dead-ends, evolutionarily speaking, as they can be incremental progress in a continuum of adaptively beneficial traits.

Although the analogy will break down (because biological evolution diverges instead of converging), you can think of this as gradient descent through a solution space. Local extrema in the solution space can trap change. An adaptation can be "successful" in the local sense simply by being better than its ancestors, but it might be a far less successful (in the sense "effective") than other branches in the tree.

Look at a simplified subset that I've seen simulated by computer (somewhere; no citation off the top of my head):
Computer starts with a population of geometric blocks/shapes/etc, in a physically modeled environment with gravity/energy/etc. Each epoch, it mutates this population randomly, tests for selection criteria, and selects those individuals which improve from the previous generation according to the selection criteria. The selection criteria is locomotion; how far can the thing move given its initial energy store and energy gathering ability. Crawling, ambling, "slithering", and something akin to walking result from this of course, but so did an object which simply fell forward under gravity and tumbled end-over-end one and a half times over its relatively large height (its longest dimension).

That was certainly a dead end and a local extremum, but that path was followed because in natural selection, the criteria is a greedy search.

So: de-selection of some trait in the mammal population could just as easily be a dead end as a necessary, incremental step in a longer, "global" path. I know that doesn't answer your question, but it illustrates the opacity of the situation and why we are largely limited to speculation. It may be possible for regeneration to be manifested in viable mammals, but we would have to be able to solve any problematic baggage it brings.

(It seems to me that with biological systems, you're constrained by two things: physical possibility and logical possibility. The latter is further constrained as a subset of the expressiveness of the language of implementation; in this case, DNA encoding. Therefore, any configuration which is physically possible and expressible is within the realm of the achievable, ipso facto. So if regeneration is expressed but deactivated in mammals, there are probably activated expressions too, including some viable, and even some successful evolutionarily speaking.)

Don't do it! (1)

Dr. Curt Conners (1257212) | more than 6 years ago | (#22765782)

It will end in pain. Trust me on this one. The world really doesn't need a Zebrafishman.

Re:Don't do it! (0)

Anonymous Coward | more than 6 years ago | (#22766326)

I saw a documentary on your condition yesterday morning. Very sad. I hope your wife and son are okay.

miRNA (3, Informative)

Anonymous Coward | more than 6 years ago | (#22765790)

FYI, as I guess this is not going to be obvious to everyone reading the article - microRNAs are a type of small RNA that are currently very popular in biology because they allow to "turn off" genes. Basically, microRNAs as well as related types of small RNA molecules switch off the synthesis of the product of a gene. Obviously, Wikipedia is going to offer more detail... Look up "RNA interference".

re-growing Hillary-babe (1)

noshellswill (598066) | more than 6 years ago | (#22765896)

Who wants a 2nd Hillary Clinton to regrow after the 1st one self-destructs ? Darwin Awards are given for a GOOD reason, ya know ...

The Paper Reference.... (1, Informative)

Anonymous Coward | more than 6 years ago | (#22765912)

Here's the reference for those who have access to Genes and Development, its not been published yet, but will be soon:
 
Viravuth P. Yin, J. Michael Thomson, Ryan Thummel, David R. Hyde, Scott M. Hammond, and Kenneth D. Poss
  Fgf-dependent depletion of microRNA-133 promotes appendage regeneration in zebrafish
 
Posting Anonymously because I don't need the karma.

Queue Intelligent Design people... (1)

RightSaidFred99 (874576) | more than 6 years ago | (#22765978)

Here they come... "But why would evolution get rid of a useful trait!". I'll tell you one possible reason why - random mutation. Offspring mutates to inactive "regen gene". Offspring lives. Bingo - whole line of offspring with inactive gene. It could also be that other mutations mitigated the benefit of this gene making it of small use and hence when it went away it didn't, in practice, limit viability of the offspring without it. For example (I'm making this up, but sounds plausible to me), cold-blooded species maybe able to live longer to allow repair mechanism to repair some types of catastrophic damage that would nearly instantly kill other species.

[Not that only ID people will wonder about this, btw, just that they love to harp on this stuff - if, indeed, the research is even correct and this is actually even in our genome somewhere.]

Re:Queue Intelligent Design people... (0)

Anonymous Coward | more than 6 years ago | (#22766466)

And to toss in a philosopher or many. Why does evolution do anything at all? As in why would it even care?

One small catch... (1)

creimer (824291) | more than 6 years ago | (#22765984)

The regenerative ability doesn't help a zebrafish when swallowed up by a larger fish.

Speed (2, Interesting)

KillaGouge (973562) | more than 6 years ago | (#22766218)

I always though it was because that it is simply faster and easier to let the body scab over the wound then to try to let the internal structure regenerate. So the human body developed the scabbing ability so that humans who did get injured could quickly escape whatever injured them.

Re:Speed (1)

amRadioHed (463061) | more than 6 years ago | (#22769906)

I think it's safe to say that both scabbing/scarring and regeneration are both damn slow compared to the mountain lion that just bit off your hand.

Mighty Mice regenerate organs too (0)

Anonymous Coward | more than 6 years ago | (#22766272)

For those that missed out on the 2005 article, Mighty Mice [wired.com] can regenerate organs too when an inactive mouse gene is activated. There are possibilities that Humans have a similar dormant gene also.

Re:Mighty Mice regenerate organs too (5, Informative)

Morten Hustveit (722349) | more than 6 years ago | (#22768060)

I recently contacted Ellen Heber-Katz, asking how the regenerating mice were progressing; they have not published anything about them in nearly two years. She replied that the mice are in fact still alive and breeding, which means that they have passed their life expectancy by at least half a year. She also said they will be releasing "lots of papers" in 2008.

Re:Mighty Mice regenerate organs too (1)

BiggerIsBetter (682164) | more than 6 years ago | (#22771602)

She also said they will be releasing "lots of papers" in 2008.
So she's been waiting on some new grad students then?

Regeneration does occur naturally in humans (0, Troll)

adj2375 (936912) | more than 6 years ago | (#22766468)

Skin, hair, fingernails, toenails. Imagine a world if evolution decided to make it so skin didn't regenerate anymore? Or if our hair stopped growing after it was cut or lost in an accident. Recall all those moments in your life that your hair was cut/ripped out and if that hair didn't grow back, what your head would look like now??
If there were humans that were "phased out" because of their regeneration ability, it was probably because they didn't have the science/technology to stop the immediate trauma of the lost limb. So they quickly died before their body had the time to regenerate (bled to death). Hence, this species of humans wouldn't have had the quantity and lifespan to properly gain a foothold in the history of humans.

Re:Regeneration does occur naturally in humans (1)

amplt1337 (707922) | more than 6 years ago | (#22774562)

Recall all those moments in your life that your hair was cut/ripped out and if that hair didn't grow back, what your head would look like now??

Like this [nrw.co.uk] ?

And /. was first on reporting the (1)

krkhan (1071096) | more than 6 years ago | (#22766484)

Plot of next Spiderman sequel.

Re:And /. was first on reporting the (0)

Anonymous Coward | more than 6 years ago | (#22767096)

But is the villain half-man, half-zebrafish, or a man with a zebrafish skin grafted onto his own skin?

"May be in mammals" (1)

The_mad_linguist (1019680) | more than 6 years ago | (#22767106)

Um... yeah. Mice have already been discovered that regenerate. (The MRL strain)

Several years ago.

It was on /.

sharks (0)

Anonymous Coward | more than 6 years ago | (#22769108)

So what... it's been long known that sharks can grow back their lost tooth, still we don't know how we could do the same...

Humans can regenerate, so I dont see the big deal (0)

Anonymous Coward | more than 6 years ago | (#22770252)

If scientists just focussed on how we already regenerate tissues in our largest organ our skin, than maybe they'd be able to figure out how to harness it for other organs instead of focusing on an animal with a different body makeup and different genes.

Zebrafishes aren't the only ones (1)

WaroDaBeast (1211048) | more than 6 years ago | (#22771520)

Axolotls do possess regenerating abilities as well.

OLD NEWS! Explosm got there first (1)

L4t3r4lu5 (1216702) | more than 6 years ago | (#22771738)

Lizard tails? [explosm.net]

Obligatory Star Trek reference... (1)

zarmanto (884704) | more than 6 years ago | (#22773266)

"The doctor gave me a pill, and I grew a new kidney! The doctor gave me a pill, and I grew a new kidney!"

"Fully functional?"

"Fully functional!"
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