Some of our closest invertebrate cousins, like this Acorn worm, have the ability to perfectly regenerate any part of their body that's cut off - including the head and nervous system. Humans have most of the same genes, so scientists are trying to work out whether human regeneration is possible, too.
Regeneration – now that'd be a nice superpower to have. Injure an arm? Chop it off and wait for it to grow back. Dicky knee? Ingrown toenail? Lop off your leg and get two for one!
It sounds ridiculous, but there's a growing number of scientists that believe body part regeneration is not only possible, but achievable in humans. After all, not only are there plenty of animals that can do it, we can do it ourselves for our skin, nails, and bits of other organs.
Perhaps humans don't regrow body parts because, unlike worms, they have an idea 'how much that stings.'
(Score: 3, Funny) by jmorris on Friday December 02 2016, @03:13AM
And of course we can all think of a few people who could lose their head, regrow it and nobody would ever notice the difference.
(Score: 1) by anubi on Friday December 02 2016, @04:11AM
Sure would be nice to regrow teeth. We get to do it once. Why just once?
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 1) by Francis on Friday December 02 2016, @04:33AM
Probably because we only need to do it once. Unlike sharks and other animals that regrow teeth regularly, we don't do anything that really requires new teeth. Our teeth tend to last a lifetime and when we lose our teeth we have a tendency to not have sufficient jaw left to keep new teeth anchored.
Until we can regenerate the bone, ligaments and gum that keep teeth in place, there's not much point in regrowing teeth as they'd fall out pretty much immediately anyways.
(Score: 1) by khallow on Friday December 02 2016, @06:57AM
we don't do anything that really requires new teeth
Eating. Teeth get lost through injury or illness.
(Score: 1) by anubi on Friday December 02 2016, @08:44AM
Exactly. Abrasion. The perfect businessword for dental insurance... not covered if the problem is a result of abrasion.
So I ended up paying full price for a crown when I thought I was "covered".
Coverage, my ass. I was just about as covered as a pretty girl at the beach wearing a string bikini, but not nearly as sweet to look at.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2) by quacking duck on Friday December 02 2016, @02:24PM
I may be getting a crown myself in the near-ish future. Did you submit a pre-determination before getting the procedure done, to see if your insurer would in fact cover it?
(Score: 1) by anubi on Saturday December 03 2016, @05:32AM
I had my first go-around with insurance about ten years ago. I had a terrible misunderstanding of the word "covered".
The first thing my dentist did was give me an estimate of dental work, then when I questioned why the bill was so high when I supposedly was "covered" by insurance, I was told that my "erosion" was due to "abrasion" ( aka. grinding teeth at night ), and not covered. His estimate was full of "not covered".
I dropped my dental insurance the next day. The dentist told me the only thing that my so-called "insurance" paid for was the office visit, exam, and cleaning. The rest was "peace-of-mind" talk to give me the illusion of being covered so I would continue to pay the premiums.
It sounded good until one reads the exclusions. Anything pricey? Not covered. They say it is in big print, but have another clause somewhere else in small print that says it isn't.
It finally sank in.
Where do insurance companies get the money to pay for all that staff, big buildings, and advertising? Gullible people like ME, who are under the illusion of thinking someone else is gonna pay my bills.
I had to wake up to the notion I was just being taken along for a ride at my expense.
Covered, my ass.
Speaking in retrospect ten years later ( I just had dental work done today, incidentally ), I am coming out better by paying the dentist directly - and I am speaking as one who has spent over ten thousand dollars in dental work over the last twenty years. ( works out to about $500/year ... most of it going into coronation ceremonies, aka "crowns" ).
I am over 65, for what that's worth... but still find dental insurance a very poor deal. You like to *think* you are covered, but all you seem to do is finance a hierarchy of desk hens to shuffle paperwork back and forth and finance rounds of high salaries and bonuses for insurance executives. They aren't making money come out of thin air to pay your bills. They just play games with words to make it *sound* like a peace-of-mind move, until the bill comes due - and you are left holding the bag.
Or, at least, that has been my experience with those goons.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 0, Troll) by Francis on Saturday December 03 2016, @04:41PM
Eating, never destroys teeth unless you're nutritionally deficient already. If your getting sufficient amounts of calcium, vitamin D, mangesium and the other necessary ingredients of teeth as well as being in generally good health, you should never have problems with teeth decalcifying. Our teeth were evolved to survive to an age of nearly a hundred and they generally do that just fine as long as you're not deficient in the necessary building blocks of healthy teeth.
Likewise, it's more or less impossible to get a cavity forming in a healthy tooth. It just doesn't happen as the tooth never weakens enough for it to happen due to the constant outflow of minerals.
(Score: 1) by khallow on Saturday December 03 2016, @05:04PM
(Score: 0) by Anonymous Coward on Wednesday December 07 2016, @03:48AM
Yes, but there's no evidence that eating causes damage to teeth. As long as your getting adequate vitamins and minerals, the teeth will continually remineralize to deal with that damage. We evolved to live decades without access to dentists.
(Score: 0) by Anonymous Coward on Friday December 02 2016, @07:24AM
Until we can regenerate the bone, ligaments and gum that keep teeth in place, there's not much point in regrowing teeth as they'd fall out pretty much immediately anyways.
This is one of the most ignorant things I have ever read. Jaw loss? What are you talking about? Have you never heard of dental implants? New teeth, just not ones you grow yourself, you have to have someone grow them in a lab, in a petri dish, cloned from stem cells taken from your bone marrow and cultured to be an exact match to the holes in your head! No, none of that is true, either. But implants are. Why do you post stuff like this, Francis? It is wrong, and does not even at least provoke or amuse.
(Score: 0, Informative) by Anonymous Coward on Friday December 02 2016, @02:06PM
his is one of the most ignorant things I have ever read. Jaw loss? What are you talking about? Have you never heard of dental implants?
I have heard of dental implants. I have heard that they cause jaw bone loss.
http://www.webmd.boots.com/healthy-ageing/news/20100119/dental-implants-and-bone-loss [boots.com]
(Score: 1, Informative) by Anonymous Coward on Friday December 02 2016, @02:15PM
Nice, a fake WebMD ran by a beauty supply company. I believe EVERYTHING I read there.
(Score: 2) by butthurt on Friday December 02 2016, @11:38PM
It isn't fake. If you go to http://www.webmd.com/ [webmd.com] and look under the "WebMD Network" section, there's a link to the BootsWebMD site.
(Score: 2) by butthurt on Friday December 02 2016, @11:46PM
Here are links to the abstract of the scientific paper.
https://dx.doi.org/10.1111/j.1600-0501.2005.01137.x [doi.org]
https://www.ncbi.nlm.nih.gov/pubmed/16117768 [nih.gov]
(Score: 0, Offtopic) by Francis on Saturday December 03 2016, @04:57AM
Hi Aristarchus, I see you're posting this BS as though you're being insightful. Ask just about any dentist out there, you lose teeth because the jaw and connective tissues can no longer support the tooth. Some people will lose teeth due to severe decay and injury, but that's less common.
You don't think the bone loss isn't visible on an X-Ray? Dentists do a lot of stupid stuff, but surely, you're not suggesting that when they consider installing implants, they just ignore the jaw when they do that?
Also, dental implants are not real teeth. They look like real teeth, but they're not real teeth. They don't have circulation and they don't recalcify the way that a real tooth does. They're typically attached to a metal screw or similar.
(Score: 0, Troll) by aristarchus on Saturday December 03 2016, @07:43AM
Wow, Francis, are you suggesting you actually know what you are talking about? This is a vast improvement. Keep it up. Tooths recalcify? I did not know that! Wow. Metal screw? Implants? Not. You almost pulled it off, Francis. But your post here reveals your ignorance even further. I will not point it out in detail, since I am already embarrassed enough for you. But seriously, you missed the fact that the original article was about regeneration of all human body parts, including jaws and gums. I know something about this, since I had a finger cut off, and it grew back.
Always acted a little strange, however. Seemed to want to salute Hitler all the time. Just call me, "Dr. Strangelove"
(Score: 2) by maxwell demon on Friday December 02 2016, @08:53AM
Any dentist will tell you that is not true. However we do it less now because dentists warned us not to do it if we want to keep our teeth.
Solution: Regrow jaw as well.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 2) by mcgrew on Saturday December 03 2016, @12:11AM
And I'm pretty sure they'll eventually be able to regrow a crushed and amputated arm or leg. I probably won't live to see it. Medical science advances really fast, though. I never thought my 20/400 eyes would ever be fixed, that I'd always need glasses, but now after surgery in 2006 when I had a CrystaLens planted in one because of a cataract I have better then 20/20 in that eye.
When I was twenty that was as impossible as supercomputers that everybody kept in their pockets. We never stop progressing.
mcgrewbooks.com mcgrew.info nooze.org
(Score: 2) by maxwell demon on Saturday December 03 2016, @07:48AM
But apparently you used the other eye for your spell-checking. :-)
(I have no idea what 20/400 means, but with a large number, I guess it's very bad).
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Saturday December 03 2016, @11:49AM
I'm pretty sure the two numbers are distance at which you can resolve something, and distance at which normal vision can resolve it.
If you can read a street sign at 400 ft, mcgrew had to be within 20 ft to read it.
(Score: 2) by mcgrew on Saturday December 03 2016, @07:56PM
That's what I get for being careless, and it's the kind of mistake I shouldn't be making, ever.
20/20 is normal eyesight. 20/400 means what I can read 20 feet (ft~1/3m) a normal sighted person can read at 400 feet. Now I can read at 20 feet what a normally sighted person can't see any farther than 16 feet (20/16). The doctor said that 98% of people's vision is better than 20/25 after surgery.
It was correctable with glasses before surgery, now I don't need glasses, even reading glasses, and I'm 64 years old. Best thousand bucks I ever spent!
mcgrewbooks.com mcgrew.info nooze.org
(Score: 0) by Anonymous Coward on Friday December 02 2016, @02:38PM
Our teeth tend to last a lifetime and when we lose our teeth we have a tendency to not have sufficient jaw left to keep new teeth anchored.
Actually much of that jaw bone loss is a result of losing teeth. Once the teeth are gone, the jaw bone gets less stimulation and so you lose jawbone.
(Score: 0) by Anonymous Coward on Friday December 02 2016, @08:02AM
I believe that technically we never regrow teeth.
The two sets are quite different (at least the roots are different).
As an aside, being able to regrow teeth would make a very big difference for old people.
If you can't eat properly, everything in your body ages much faster.
(Score: 3, Interesting) by Taibhsear on Friday December 02 2016, @04:27PM
Correct. Here's a link with some photos of the two sets of teeth in a shaved skull so you can see them more clearly.
https://io9.gizmodo.com/5910844/the-mouth-of-a-child-is-a-terrifying-thing-to-behold [gizmodo.com]
(Score: 3, Funny) by deimtee on Saturday December 03 2016, @11:52AM
I don't think I want to shave with a razor like yours. It seems a tad aggressive.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 0) by Anonymous Coward on Friday December 02 2016, @12:34PM
How I would love to mark this down as introspection and self-awareness... But I suspect you are talking about others? :-)
(Score: 2) by Azuma Hazuki on Friday December 02 2016, @03:28PM
I'd love to try the experiment. Here, stick your head through this hole with the giant, slanted razor blade a few feet above it. You may feel a sharp pinch. I'll let you know the results of the experiment once I find a good medium :D
I am "that girl" your mother warned you about...
(Score: 0) by Anonymous Coward on Friday December 02 2016, @03:44AM
“You see,” he began, “the whole problem was that the ambassador is very definitely not a female. That
threw me for a while, but I couldn't give it my full attention until I figured out what had caused its problem
in the first place. But there were so many hints I should have seen it even sooner: the fact that its tissue
kept growing, even when it wasn't cultured; the fact that we couldn't find any sexual apparatus; the fact
that there were no outlets for spores. So of course, what could it be but an entity that is capable of
reproduction by fission, and hence of regeneration? I should have guessed something like that the first
day, when only one of my scrapings drew any blood at all, and that coagulated in just two or three
seconds.”
“But can it grow a head?” asked Hammett. “After all, you've removed its brain and all its orifices. Even a
starfish has to have part of the core remaining to regenerate.”
“I think it will. If not, the body and head would probably have died immediately. Neither did, which is
why I destroyed the head: I didn't want that mindless pseudo-cranium growing another body. Also, if I
can coin a word, we occasionally tend to Earthomorphize, to give certain Earthly qualities to all forms of
non-Earthly life. It seems unlikely to me that any creature could survive with its head severed, but the fact
remains that it is indeed surviving. However, the really major problem still remains.”
“And what is that?” asked Hammett.
“The new brain won't know that it's an ambassador, or that we saved its life—so I think we'd better
prepare for a little war.”
(Score: 0) by Anonymous Coward on Friday December 02 2016, @05:17AM
Wtf?
(Score: 2) by rob_on_earth on Friday December 02 2016, @09:16AM
Just google i.....
crap! non of the phrases in that post produce even a hint at a real text.
Anyone got a source?
(Score: 0) by Anonymous Coward on Friday December 02 2016, @09:42AM
I did JFGI
sigh.
(Score: 2) by TheRaven on Friday December 02 2016, @11:12AM
Google produced a link to the 2016 Democratic Primary Debate as he top hit.
Bing produced a link to Meryl Streep's Wikipedia page as the top hit.
sudo mod me up
(Score: 0) by Anonymous Coward on Friday December 02 2016, @12:16PM
Google thinks this is about Tara Moss or a feminist book shop
(Score: 1, Informative) by Anonymous Coward on Friday December 02 2016, @07:47PM
https://duckduckgo.com/?q=%22The+new+brain+won%27t+know+that+it%27s+an+ambassador%22 [duckduckgo.com]
http://www.rulit.me/books/birthright-read-241876-31.html [rulit.me]
http://dado.msk.ru/rlib/utf8/378138.html [dado.msk.ru]
Birthright, by Mike Resnick, Chapter 9, The Medics
(Score: 0) by Anonymous Coward on Saturday December 03 2016, @12:04AM
I 100% AC - someone upvote parent please, those are golden links
(Score: 2) by Snotnose on Friday December 02 2016, @03:46AM
is rather pointless.
I blame the French revolution folks who made the guillotine a necessary addition to every French asshole's repertoire.
When the dust settled America realized it was saved by a porn star.
(Score: 2) by mcgrew on Saturday December 03 2016, @12:17AM
To be fair, if I were the victim I'd prefer it to an axe, or a jehadist's knife.
mcgrewbooks.com mcgrew.info nooze.org
(Score: 4, Interesting) by opinionated_science on Friday December 02 2016, @09:55AM
Another ludicrous attempt to get funding, without even a basic thought of the logic.
The species that *can* regrow limbs (Salamander) may have a much bigger genome (10x human), but they are also *much* smaller.
I will go out on a limb (sic) and say, that we could regrow a leg - only it would take 15 years and need a suitable environment to ensure the musculature, bones and venal system all become adapted.
Regrowing a tooth is relatively easy, but still might take 6 months.
One of the facts glossed over is just how much of our bodies *does* regrow on a regular basis - only it is a massively parallel action (everywhere, a little bit).
There is a colossal energetic cost to growing an animal the size of humans.
That is why it takes 20 years....
...and a great deal of beer!
(Score: 4, Insightful) by GreatAuntAnesthesia on Friday December 02 2016, @10:39AM
I'm pretty sure that most of your counterpoints could be addressed by technology, and even if not I don't think those restrictions make it entirely useless. 15 years to grow a new leg? Well, better than nothing, except for the very elderly. 6 months to replace a tooth? Yeah, I'd go for that right now if the cost was right (and in theory, the cost could be very low), I have several teeth that I'd like replaced.
Also, sometimes just a small amount of regenerated tissue could be life changing: Imagine if we could regenerate damaged spinal cords? Regrow missing fingers and toes? Genitals? Eyes and ears?
(Score: 3, Interesting) by opinionated_science on Friday December 02 2016, @11:01AM
I am working proximal to some of this technology - stem cells can repair some very subtle structures.
Organs will need considerable amounts cellular framework, but might be doable (heart, kidneys).
But a complex biomass such as a limb, has issues due to the fundamental mechanism of cellular growth.
My musing is that our technology might be able to "print" or otherwise give a major structural template, it maybe possible.
But to my original point, energetics will make it slow... (think of reverse entropy - you are turning a bag of chemicals into a tissue! That's some energetic incline...).
(Score: 3, Interesting) by GreatAuntAnesthesia on Friday December 02 2016, @12:49PM
> My musing is that our technology might be able to "print" or otherwise give a major structural template, it maybe possible.
In other words it's a choice between "growing a new leg" as in "start off with a tiny foetus-leg that gradually develops into an adult-sized one" and "growing a new leg" as in "skip the intermediate steps and just build an adult leg directly."
i.e. https://www.youtube.com/watch?v=h9OBbsLYGOE [youtube.com] vs https://i.ytimg.com/vi/sWr7rcoAWaQ/maxresdefault.jpg [ytimg.com]
(Score: 0) by Anonymous Coward on Saturday December 03 2016, @12:23AM
It's "build the new leg in the lab, then surgically attach" really.
(Score: 2) by geb on Friday December 02 2016, @10:48AM
Cold blooded creatures have far larger genomes than mammals because they have multiple overlapping layers of metabolism, to allow them to function at a range of temperatures. With a fixed body temperature, you can live with a single enzyme to do a single job. If the environment determines your body temperature, you need several enzymes, all tuned to operate at different temperatures.
Also, size has nothing to do with complexity. Many whales have about the same size of genome as humans.
(Score: 2) by opinionated_science on Friday December 02 2016, @10:57AM
I did not imply size had anything to do with complexity - I happened to work with the group that sequenced that beasty!
I was pointing out that novelties like huge genomes (this used to be used as grant justification..) , are not sufficient to overcome the energetics of the biochemical machinery required to achieve regrowth.
An interesting point about metabolic diversity, though I have not read anything that directly enumerates the enzymatic taxonomy of the non-mammalians.
(Score: 0) by Anonymous Coward on Saturday December 03 2016, @12:35AM
> Many whales have about the same size of genome as humans.
And they are -extremely- intelligent, and certainly some species not only have language but have oral traditions.
> size has nothing to do with complexity
Size has to do with complexity of regrowth actually. The larger the organism the larger its constituents at the high side (blood vessels, bones, soft organs) but the same size at the smallest (elephants don't have larger capillaries than mice; individual cell size doesn't scale with (multicellular) organism's size, etc.). So you end up with a 'deeper hierarchy' for blood, which is much more work to build than a shorter hierarchy eg. at the capillary level in human dermis (which we do regrow). You end up with innervation that branches more levels deep to control an elephant's hamstring vs. a mouse's (citation needed?). As someone else has pointed out the energretic cost matters: regrowth of a newt leg is like going to the gym for a few weeks, but regrowing an arm would be like going to the gym for years and years, and due to size scaling (note gestational and developmental times *do* correlate to size) by volume it gets costly, fast.
(Score: 3, Insightful) by q.kontinuum on Friday December 02 2016, @11:44AM
A cow in a feedlot becomes ready for slaughter after ~13 months. That's way more muscle an bone grown than would be necessary to re-grow a human bone.
Registered IRC nick on chat.soylentnews.org: qkontinuum
(Score: 2) by q.kontinuum on Friday December 02 2016, @11:46AM
I mean of course "[...] to re-grow a human arm or leg"
Registered IRC nick on chat.soylentnews.org: qkontinuum
(Score: 2) by opinionated_science on Friday December 02 2016, @11:55AM
well the block diagram in my mind has "bioreactor" , but yeah....
(Score: 2) by edIII on Friday December 02 2016, @06:25PM
I dunno about the rest of your post, but I do believe parents need a lot of beer to raise a child till 20.
Technically, lunchtime is at any moment. It's just a wave function.
(Score: 2, Insightful) by Anonymous Coward on Friday December 02 2016, @10:56AM
Could this be simply because regrowing limbs requires lots of stem cells, and those are limited in the number of divisions they can do, so regrowing something large would cut a lot of time off your expected life span. Meanwhile, getting rid of the limit to the number of divisions happen all the time by accident, and is named "cancer".
(Score: 3, Interesting) by Immerman on Friday December 02 2016, @03:01PM
Actually, stem cells have a much larger Hayflick Limit than most, potentially infinite for some of the more pluripotent strains if provided with the right "chemical soup" to allow them to stop or even reverse telomere loss.
I'm pretty sure most stem cells are also pretty localized, so even if regrowing a leg did drastically reduce the "downstream" cellular lifespan, it would mean only that *the leg* had a reduced life span, not the whole organism.
And eliminating the Hayflick Limit isn't what causes cancer - it's just what makes certain kinds of cancer particularly dangerous. What makes cells cancerous isn't just that they can replicate indefinitely, but the fact that they keep replicating without a reason, rather than waiting to be signaled to replicate in order to repair damage. It generally takes several independent mutations in a pre-cancerous cell line before it becomes truly dangerous, as various "checks and balances" get removed.
(Score: 0) by Anonymous Coward on Saturday December 03 2016, @12:42AM
> I'm pretty sure most stem cells are also pretty localized
Yeah, no. Turns out they can be extremely mobile, it's just very uncommon. IIRC this was done with mitochrondial swaps in local pluripotents, later found in pluripotents (and downstream) across the organism. I forget the location and model organism, I think it was mice though. One fascinating find was unipotence to pluripotence, I know it's old news now but it still impresses me.
(Score: 2) by Immerman on Thursday December 08 2016, @09:44PM
Seems like we're not disagreeing - very mobile in rare circumstances would not be inconsistent with fairly localized under normal circumstances.