Although the subject is interesting the page, published on 16th March 2010, is poorly researched blog-spam. It is essentially just copied from one of the numerous pages that say the same thing, such as this one published on 27th January 2009
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.
Lots of animals can do that, although the ones that can survive in a body—for example, tapeworms—usually start preferring to survive in that body (it relieves you of all the work of creating a biological equilibrium of your own), so they evolve to hold on inside instead of coming out.
They are jellyfish, and jellyfish thrive on the recent development that is large amounts of nitrates in the oceans. Think greenhouse gases, but instead of heat in the atmosphere, it's algae and jellyfish in oceans.
Overfishing is the culprit here. With less fish in the seas jellyfish - immortal and regular - can procreate much more easily, and have access to more food. Here's a relevant article: http://www.digitaljournal.com/article/273850
I am surprised the tourism lobbies are not fighting the fishing lobbies on that one.
Good observation. A spike in population implies a recent change in the organism or its environment. Since most multicellular organisms cannot evolve that quickly, it's more likely that there was a change in the environment which this organism was able to take advantage of. I doubt that their numbers are spiking because "they are bale to bypass death".
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.
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.
I believe that they do,and at very high rates but they get run over by cars much more frequently.
I think that neither really makes them less 'immortal' in the sense that this article means.
Though I can see the argument that errors in cell replication leading to cancerous growths could be counted as a form of natural life span limitation, I would be surprised if it didn't also happen to this jellyfish.
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.
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.
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.
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.
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?
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.
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.
It all depends on how well the organism can distinguish between the incorrectly copied DNA (this is probably what you mean by damage) and the right sequence. Given that most of the DNA will be copied correctly, if slightly wrong bits can be detected and excised, then the organism should stay healthy. Biological codes are just as digital as computer ones.
I think @hristov is referring to the cells eventually not being able to perform their function... as a result of friction (or something else) eventually making each cell less effective.
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!
"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."
This is the same sort of reasoning as "either I win the lottery or I don't, so there's a 50% chance". More mutations are neutral, than harmful, than beneficial.
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.
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?
> That means 2/3 of the time- mutations do nothing or help the organism.
Imagine you have a series of integers being multiplied. Each step, you increase 1/3 of them and decrease 1/3 of them - you leave the remaining 1/3 untouched.
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.
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...)
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.
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.
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).
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.
"The City and the Stars" by Arthur C. Clarke includes that concept—humans edit their memories before their death and recover them after being born again. I recommend reading it, just for the extreme transhumanism within the story.
Depends on whether or not you can selectively preserve memory. If could be useful if it acted sort of like amnesia where you retain things like muscle memory and factual memory, but not personal memory. Though I wouldn't necessarily look forward to the prospect of losing my life experiences.
It still is immortality. In a world with a large population we might think more about what makes us individuals as what we wish to preserve, but from a survival-of-the-species point of view, it is immortality.
I wonder if this kind of immortality would be that great. Most of my
motivations to do things now come from the time limit factor. If I
were immortal with unlimited memory, I think I'd just procrastinate and continue to postpone
all the tasks I have to accomplish just because I can.
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.
Did they like ... just evolve or something? You'd think they'd have spiked before now and reached equilibrium.