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It kind of depends on how you define "lifespan," although some recent research seems to suggest that turtles may never die of old age.
But how old is an ameba? Do you date from the last division, or from the first ameba?
I was going to say the same thing, Darby.
Do you don't consider dividing as dying, (and usually it is not considered as dying), then you can never know how old a single celled organism is.
PS: I remember a similar debate a few months ago.
It matters not how strait the gate
How charged with punishment the scroll
I am the Master of my fate
I am the Captain of my soul.
Me too. And about ageing in single cell organism, you can read this paper. Have fun.
Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)
The estimate on Galapagos tortoises was revised up a few years' back.
Someone doing restocking of eggs (they and hatchlings get quickly dispatched by rats and so need to be gathered and raised to non-ratfood size before release) estimated from shipping accounts when some of the islands picked up their rat populations and figured that on at least one island there had been no new tortoises for over 300 years (but there were still lots of old ones there).
And a longterm study of regular turtles in Michigan (there was an article in Discover a couple of years ago) found that many turtles that were present as adults back in the 1920's were still around, showing no sign of aging, and their reproductive rates were actually still rising. I've had turtles, adults of uncertain age when rescued, in my lab for 25 years, and they have not changed a bit (maybe they're a teensy bit bigger).
so, what is the revised lifespan?
and about the turtle in your lab, animal in captivity do tend to have longer lifespan
300 years plus.
The lifespan effects of captivity vary - there's no way to be sure whether it works that way with reptiles (except that they're unlikely to be predated on).
Lifespan is a weird thing, anyway. How long is a non-domestic animal's lifespan? Could you design a field study to determine how long a given critter lives in the wild (and be sure that anything you do to find out wouldn't stress it and shorten that span)? It can be done with large animals in a semi-confined space (like elephants in a national park, or Galapagos tortoises), but how would you do it with, say, a monkey, or a swordfish, or a pond turtle?
The lifespans you find in lists are largely anecdotal. Kind of like their speeds, which are all based on individual guesses.
This is the immortal being with the longest lifespam even if its not an animal but natures only error was that made this immortal being so small hehe : Turritopsis nutricula or immortal jellyfish is a hydrozoan whose medusa, or jellyfish, form can revert to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage. It does this through the cell development process of transdifferentiation. Cell transdifferentiation is when the jellyfish "alters the differentiated state of the cell and transforms it into a new cell. In this process the medusa of the immortal jellyfish is transformed into the polyps of a new polyp colony. First, the umbrella reverts itself and then the tentacles and mesoglea get resorbed. The reverted medusa then attaches itself to the substrate by the end that had been at the opposite end of the umbrella and starts giving rise to new polyps to form the new colony. Theoretically, this process can go on infinitely, effectively rendering the jellyfish biologically immortal, although in nature, most Turritopsis, like other medusae, are likely to succumb to predation or disease in the plankton stage, without reverting to the polyp form. It's one of the longest-living organisms in the world, However, no single specimen has been observed for any extended period, and it is impossible to estimate the age of a specimen.
On average, reptiles live longer than mammals and birds. The giant tortoise is the longest living animal, averaging a whopping 152 years. The box turtle is a close second with 123 years, followed by the turkey buzzard at 118 years. These averages all assume the possibility of the animal getting sick and dying young. A healthy tortoise can live upwards of 170 years!
Last edited by canalon on Tue Jul 13, 2010 2:10 pm, edited 1 time in total.
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