
The world's only immortal animal - ph0rque
http://green.yahoo.com/blog/guest_bloggers/26/the-world-s-only-immortal-animal.html
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glhaynes
_Because they are able to bypass death, the number of individuals is spiking._

Did they like ... just evolve or something? You'd think they'd have spiked
before now and reached equilibrium.

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CUViper
According to one of the linked articles, they are suspected to be hitchhiking
in the ballast of large ships, so their habitat is unnaturally expanding.
There could always be other factors too, like an over-fished predator.

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jared314
That sounds similar to the C. taxifolia Algae threat.
<http://www.pbs.org/wgbh/nova/algae/chronology.html>

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steveitis
It's my understanding that certain turtles don't exhibit telomere shortening,
and are effectively 'immortal' as well in that they don't age.

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zackattack
Do they not get cancer?

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Groxx
There's still background radiation.

That the telomere doesn't shorten basically means the DNA doesn't "age"; cells
don't become more likely to mutate after X duplications begin to damage the
code, like ours do.

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zackattack
Is telomere shortening the sole cause of DNA replication errors? (Besides
radiation, which damages the DNA directly?)

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a-priori
No, it's not. DNA transcription errors occur all the time in our bodies, but
there are elaborate repair mechanisms in the DNA that either correct it or, if
its uncorrectable, kill off the cell.

But, sometimes these mechanisms fail and a cell survives with mutated DNA. If
the right genes are mutated, then it grows uncontrolled and you've got cancer.

In order to get immortality, these repair mechanisms would have to be as
robust after 1000 years as they are after 20 years. In humans, the repair
mechanisms tend to degrade as you age, which is why, the theory goes, people
are more likely to get cancer as they get older. It's not that there are more
errors then, but that they're not corrected as well.

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kissickas
What about Hydra? <http://en.wikipedia.org/wiki/Biological_immortality#Hydra>

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Groxx
Yeah, I think there are a few animals like that. So while it's not likely the
only "immortal" animal, this jellyfish does definitely seem to have a _unique_
kind of immortality.

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sambeau
Most living things are 'immortal' in that they do not age. This is true of
bacteria, fish, lobsters, birds etc.

It just happens that most creatures we have close contact with - i.e. Mammals,
do.

What is unusual about this Jellyfish is not it's lack of ageing, but it's
ability to return to "childhood" at times of stress and then become an adult
once again, later.

It's a weird and fascinating concept for us Mammals. Although I am pretty sure
I wouldn't want to repeat my teenage years over and over.

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paraschopra
Like most living systems, Jellyfishes are self organizing systems. But the
difference is that a jellyfish is quite minimalistic in structure and their
neural system is simple too. And most certainly, it lacks emotions of any
kind.

That is what amazes me about jellyfishes: a very, very simple system
genetically programmed to for reproduction lacking any "purpose". And, now
they say it can even go back to its proto stage. Wow, evolution is
fascinating.

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woadwarrior01
Biologically speaking, the only "purpose" of every organism is to just to
reproduce. I've always been fascinated by the idea of how our brain acts like
a higher level abstraction on top of the rather slow process of evolution,
since ideas evolve a couple of orders magnitude faster than plain old
evolution.

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bh23ha
What about single celled life? In a division one call seems to get renewed
while another seems to age, you say. What if this animal is doing something
similar?

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pyre
There are a number of things that lead to cell mortality in multi-cellular
organisms.

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whyenot
_says Dr. Maria Miglietta of the Smithsonian Tropical Marine Institute._

There is not Smithsonian Tropical Marine Institute. The author of this article
meant the Smithsonian Tropical _Research_ Institute.

[http://www.stri.org/english/research/facilities/marine/bocas...](http://www.stri.org/english/research/facilities/marine/bocas_del_toro/postdocs.php)

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jdunck
<http://en.wikipedia.org/wiki/Turritopsis_nutricula>

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gort
It's worth noting that there's probably no fundamental reason why animals that
live forever couldn't evolve. Sadly though, evolution favours whatever genes
multiply fastest. There are trade-offs between living forever and reproducing
as quickly as possible; and selection favours the latter.

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hac
As some already noted, there are other animals like this:
<http://en.wikipedia.org/wiki/Negligible_senescence>

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hristov
What about enthropy? I would expect that after going between polyp and adult
many times the DNA of some cells may get damaged, and the cells may not
convert correctly to their new cell types, and eventually the organism will
become more and more wrong until it dies.

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dbz
In humans, DNA Polymerase (the thing that replicates DNA) makes about 1 in
10,000 base pairing errors. After other enzymes "proof read"- the mistake
count is 1 in 1 billion. Keep in mind, that there is a lot of "junk DNA." junk
DNA is DNA that does nothing, but a lot of mistakes are made in the junk DNA
and the introns (parts of the junk DNA that do nothing) are cut out and we
only keep in exons.

Now I have another _very_ important point to make. Errors in base pairing,
also known as mutations- are usually very very good. Why? Because 1/3 of
errors are bad, 1/3 do absolutely nothing, and 1/3 are good and provide
benefits. That means 2/3 of the time- mutations do nothing or help the
organism.

So, I guess I am saying I think you should expect a different result =p.
Mutations are good!

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hristov
Suppose the one in a billion number is right. But that thing has to have at
least several billion cells. So each transformation will ensure that there are
several cells that go wrong.

I mean people live a limited time and do not have to have their cells do these
complex transformations, yet a large part of us still manage to get cancer
before we die.

Also, I do not believe that stuff about mutations being just as likely to be
good. If you have a complex organism any change is far more likely to be
detrimental than positive. When you hit your watch with hammer, it is very
unlikely you will get a better watch. It is much more likely you will get a
broken watch.

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dbz
The number is right, and again one mutation most certainly will NOT ensure a
cell goes wrong. Most "bad" mutations are not anything like cancer.

You don't have to believe the "stuff" about mutations being just as likely to
be good because it is true. Furthermore, that's not how cancer works.

Cancer might happen when a beam of light hits the nucleus and blasts the DNA
out of the nucleus. (This is normally at x-ray or gamma-ray level, and the
common skin cancer has to do with our repair cycle for skin when UV light hits
it, and our not repairing fast enough.) Other cancers happen other ways, and I
don't want to pretend I know everything either, but I do know- the idea of the
cells being degraded enough over time to just kill the animal is a little far
fetched. Yeah, could happen, but the degrading will take a _hell_ of a long
time based on what I know.

Also on a side note: How many base pairs do you think there are? That 1 in 1
billion may look bigger if I tell you that there are 30,000 base pairs in
humans, most of which is junk DNA, and then there are also probably quite a
few less in a sea jelly. 1 in 1 billion is a pretty big number now isn't it?

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donaq
We need to capture one and feed it for a couple of centuries to see if it is
truly immortal.

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javajones
So is this animals natural predator diminishing in numbers, which is why they
are spiking?

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pyre
It could be any number of things. I saw a documentary about a different type
of jellyfish that is becoming a problem in East Asia due to a combination of
over-fishing of predators and warmer waters which increases their reproduction
yields.

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MattSimmons
In that case, they'd better be delicious, in order to keep the population
down...

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khelloworld
Someone should start a business that breeds/sells those 'immortial beings.'

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stevejohnson
This is a decidedly time lord-like form of immortality.

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JCThoughtscream
But /how do they taste/?

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itistoday
This form of immortality displeases me. I'd rather not turn back into a fetus
for the sake of immortality.

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tyler
Personally, I'm not particularly picky about my forms of immortality.

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boucher
Seems like immortality without memory is useless, so really that's the
question.

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patio11
Write stuff down! BAM, problem solved. (Seriously speaking, consider the sci-
fi short story possibilities of an individual who had to reboot every 80 years
or so, but who had had access to a computer and competent legal/investment
advice for roughly the same timescale as the present-day Catholic Church has
been in operation. Age 0 through 24 is essentially one _long_ data dump, but
he's gotten pretty good at constructing his curricula, given a few millenia to
practice it. They call him Jerome the Eldest, he is richer than most nations,
and he lives life depressed and alone, until one day...)

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a-priori
Keeping a journal probably wouldn't help. Take the case of Clive Wearing, who
developed anterograde amnesia after a bout of encephalitis. He can conduct an
orchestra, but he can't remember what he did 10 minutes before.

He keeps a journal. It's a timestamped log of him saying that he's "finally
awake" over and over.

<http://en.wikipedia.org/wiki/Clive_Wearing>

In addition to robbing you of your past, amnesia makes the future unknowable.
Amnesia traps you perpetually in the present with no way of improving it.

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kiiski
But unless I missed something, amnesia doesn't have anything to do with the
subject. In this case you don't forget what you did 10 minutes ago; you forget
what you did 80 years ago (which I suppose most people do anyway).

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a-priori
Yes, I agree this has gone off-topic. This was a rebuttal to patio11's remark
that immortality without memory could be compensated for by writing everything
down.

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albertcardona
Planarians (flatworms) have many immortal species as well. They are able to
grow and degrow, changing their cell populations to the proportions found in
juveniles. They are able to divide by fission, where the head remains and the
tail grows a new brain _from scratch_.

