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What's the life expectancy of individual polyps?


Partially Submerged

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Yes. In theory.

 

Good deal and the theory does make sense.. but how would you pick which of the 2 nems was the mother at that point? In each the cells would be going through their lifecycles, but the actual two full organisms would seem to be the same age?

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Shi-at, nice find! Those are some old corals. And has only taken us a couple of decades to destroy so many of them. :(

 

As someone else mentined, I posted some incorrect information -- that's actually the age of old/dead coral formations that are above sea level or something lol

 

DNA has a life span. So does RNA. Polyps absolutely age and can die from old age. Nothing can live forever. A cell may divide and pass its genetic material on, and that being a clone, the cell technically "lives forever" but the original cell does not. The daughter cell lives, but the mother cell will die.

 

Edit: The halflife of DNA is ~521 years. RNA varies, but bacterial mRNA has a halflife of around 2 minutes.

 

So this is misleading, since old cells are constantly being replaced by old cells in an organism (along with DNA/molecules). Like, if you're older than 50, probably most of your living cells are less than 20 years old.

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So this is misleading, since old cells are constantly being replaced by old cells in an organism (along with DNA/molecules). Like, if you're older than 50, probably most of your living cells are less than 20 years old.

Yeah I didn't write that very clearly. I kept it way too simple. The hayflick limit basically is the limit to the number of times a cell can divide before dying. Each time a cell divides, the DNA telomeres shorten a bit. I'm not sure the exact number of divisions a cell can undergo before entering senescence and then apoptosis, but I think it varies between 40 and 60 divisions depending on the cell type. Cancer cells are cells that have mutated in such a way that they do not stop dividing, they just keep going.

 

Edit: Aging is thought to be due to DNA damage. Eventually we basically take so much DNA damage resulting in mutations that our body simply can't keep going and organs/cells/systems fail and we die.

 

Edit edit: I know you know this Hypo, I'm just writing it down for others

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There are biologically immortal organisms, organisms that truly do not die from old age. Like the immortal jellyfish.

 

Nobody said it is the same for corals, but fact is there are biologically immortal beings. Not through asexual reproduction and all that. Actual no-death-by-old-age.

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that is tremendous, think of the centuries or millennia it took to grow that big.

Yeah I didn't write that very clearly. I kept it way too simple. The hayflick limit basically is the limit to the number of times a cell can divide before dying. Each time a cell divides, the DNA telomeres shorten a bit. I'm not sure the exact number of divisions a cell can undergo before entering senescence and then apoptosis, but I think it varies between 40 and 60 divisions depending on the cell type. Cancer cells are cells that have mutated in such a way that they do not stop dividing, they just keep going.

 

Edit: Aging is thought to be due to DNA damage. Eventually we basically take so much DNA damage resulting in mutations that our body simply can't keep going and organs/cells/systems fail and we die.

 

Edit edit: I know you know this Hypo, I'm just writing it down for others

we must keep in mind proteins like telemerase that can re form telemeres and suppress ageing, potentially indefinitely.

There are biologically immortal organisms, organisms that truly do not die from old age. Like the immortal jellyfish.

Nobody said it is the same for corals, but fact is there are biologically immortal beings. Not through asexual reproduction and all that. Actual no-death-by-old-age.

lobster is one example, same as many trees
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Partially Submerged

DNA has a life span. So does RNA. Polyps absolutely age and can die from old age. Nothing can live forever. A cell may divide and pass its genetic material on, and that being a clone, the cell technically "lives forever" but the original cell does not. The daughter cell lives, but the mother cell will die.

 

Edit: The halflife of DNA is ~521 years. RNA varies, but bacterial mRNA has a halflife of around 2 minutes.

 

Well, yes, but the organism can - in theory - live forever. This is the "immortal" jellyfish: http://en.wikipedia.org/wiki/Turritopsis_dohrnii

 

For most organisms, aging is not relevant, of course. I listened to a lecture on senescence a few weeks ago. The professor used coffee mugs in a hotel as an example. Say the hotel buys 1,000 mugs. They will all break at some point, but at which exact time an individual mug breaks is more or less coincidence. That's - very simplified - the mortality pattern for animals. Of course, there are particularly dangerous life periods and events, but other than that an older animal has more or less the same chance of dying as a younger one because death is usually due to disease, accidents, predators, etc. Humans, on the other hand, are more likely to die the older they are (infancy being an exception) until at some very old age, that curve levels off. What's interesting is that this professor said this senescence curve is a pretty recent thing. Just 200 years or so, humans died a lot more like animals (or the mugs in the example). Someone in their 40s was more or less as likely or unlikely to die as a 60-year-old.

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Telomerases are partly what cause cancer.

true, but then again a lobsters body is probably equipped in some way to avoid these risks. Also his environment to a degree helps prevent cancer in the first place. To think of in the deep sea where lobsters can be found there is significantly less UV and similar radiation to mutate cells.
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true, but then again a lobsters body is probably equipped in some way to avoid these risks. Also his environment to a degree helps prevent cancer in the first place. To think of in the deep sea where lobsters can be found there is significantly less UV and similar radiation to mutate cells.

My lobster will live forever and reign supreme! Bow before him you puny mortals. :D

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My lobster will live forever and reign supreme! Bow before him you puny mortals. :D

too bad crustaceans die from moults occasionally, that's how I've lost many of them crayfish.
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too bad crustaceans die from moults occasionally, that's how I've lost many of them crayfish.

Yes so I hear, supposedly lack of iodine can cause this but there are many other reasons. Mine has gone through 3 molts so far, they seem to be about 6-8 weeks apart. He regrew his whole arm he dropped off when I first put him in the tank so I have decided he is immortal. ;)

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What about the HeLa line of "immortal" human cells? http://en.wikipedia.org/wiki/HeLa

 

There has been more than 20 tons of cells grown since 1951!

 

 

 

Those are a cancer line. They were made immortal by becoming a cervical cancer in Henrietta Lacks. We do it with many human cells in lab settings through viruses, etc.

true, but then again a lobsters body is probably equipped in some way to avoid these risks. Also his environment to a degree helps prevent cancer in the first place. To think of in the deep sea where lobsters can be found there is significantly less UV and similar radiation to mutate cells.

They can still get cancer. Every multicellular organism can get cancer. Fossil evidence shows that even the first multicellular organisms got cancer. Lobsters eventually die from energy exhaustion during molts. They can't keep going. They do express telomerase throughout adulthood, which explains their "immortality" but eventually their carapace becomes too large to molt easily, and they die during a molt.

 

Well, yes, but the organism can - in theory - live forever. This is the "immortal" jellyfish: http://en.wikipedia.org/wiki/Turritopsis_dohrnii

 

For most organisms, aging is not relevant, of course. I listened to a lecture on senescence a few weeks ago. The professor used coffee mugs in a hotel as an example. Say the hotel buys 1,000 mugs. They will all break at some point, but at which exact time an individual mug breaks is more or less coincidence. That's - very simplified - the mortality pattern for animals. Of course, there are particularly dangerous life periods and events, but other than that an older animal has more or less the same chance of dying as a younger one because death is usually due to disease, accidents, predators, etc. Humans, on the other hand, are more likely to die the older they are (infancy being an exception) until at some very old age, that curve levels off. What's interesting is that this professor said this senescence curve is a pretty recent thing. Just 200 years or so, humans died a lot more like animals (or the mugs in the example). Someone in their 40s was more or less as likely or unlikely to die as a 60-year-old.

There are some instances of biological immortality, but the organisms involved are very simple, i.e. Jellyfish. Senescence is an interesting topic, for sure. But even there it is only a few jellyfish that express specific proteins to replenish their Cells post-reproduction.
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Yes so I hear, supposedly lack of iodine can cause this but there are many other reasons. Mine has gone through 3 molts so far, they seem to be about 6-8 weeks apart. He regrew his whole arm he dropped off when I first put him in the tank so I have decided he is immortal. ;)

I've also read somewhere calcium in the water can help some.
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Those are a cancer line. They were made immortal by becoming a cervical cancer in Henrietta Lacks. We do it with many human cells in lab settings through viruses, etc.They can still get cancer. Every multicellular organism can get cancer. Fossil evidence shows that even the first multicellular organisms got cancer. Lobsters eventually die from energy exhaustion during molts. They can't keep going. They do express telomerase throughout adulthood, which explains their "immortality" but eventually their carapace becomes too large to molt easily, and they die during a molt.There are some instances of biological immortality, but the organisms involved are very simple, i.e. Jellyfish. Senescence is an interesting topic, for sure. But even there it is only a few jellyfish that express specific proteins to replenish their Cells post-reproduction.

never said it was impossible for lobster cancer, just it would be more difficult for them vs us getting cancer. We need to keep in mind its not totally out of the realm of possibility for a coral to be ageless so to speak.
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