Discussion in 'The Sanctuary' started by TheBigPayback, Aug 7, 2013.
Yes. deff sig worthy.
I believe it was in hopes thread
ahahaha good times!!!
There are a few species that are functionally immortal. Which is to say that given the necessities of life, they will never succumb to old age.
lobsters die of natural causes... couldnt that be considered old age?
all functionally immortal means is that they basically continue growing till they die
its not like theyd live forever if kept in a safety box
Speaking of immortal lobsters. i take back the appeal of my statement about bugs.
Not sure which thread but when we discussed bugs and how they didnt always exist. well technically thats actually an accurate statement.
they didnt always exist. for example ants are only 230m yrs old
then we have cockaroaches which are quite a bit older and
the oldest known bug is the dragon fly.
but they didnt all exist at the same point in time.
So they didnt always exist.
Biological immortality is an absence of aging, specifically the absence of a sustained increase in rate of mortality as a function of chronological age. A cell or organism that does not experience aging, or ceases to age at some point, is biologically immortal.
Biologists have chosen the word immortal to designate cells that are not limited by theHayflick limit, where cells no longer divide because of DNA damage or shortenedtelomeres. The first and still most widely used immortal cell line is HeLa, developed from cells taken from the malignant cervical tumor of Henrietta Lacks without her consent in 1951. Prior to the 1961 work of Leonard Hayflick and Paul Moorhead, there was the erroneous belief fostered by Alexis Carrel that all normal somatic cells are immortal. By preventing cells from reaching senescence one can achieve biological immortality; telomeres, a "cap" at the end of DNA, are thought to be the cause of cell aging. Every time a cell divides the telomere becomes a bit shorter; when it is finally worn down, the cell is unable to split and dies. Telomerase is an enzyme which rebuilds the telomeres in stem cells and cancer cells, allowing them to replicate an infinite number of times. No definitive work has yet demonstrated that telomerase can be used in human somatic cells to prevent healthy tissues from aging. On the other hand, scientists hope to be able to grow organs with the help of stem cells, allowing organ transplants without the risk of rejection, another step in extending human life expectancy. These technologies are the subject of ongoing research, and are not yet realized.
nobody said they always existed.
this is all i was getting at.
''It’s true that lobsters continue eating, reproducing and growing until the end. And there is an end—they’re not immortal. But like most decapod crustaceans, which also include crayfish and shrimp, they have indeterminate growth. That means they don’t reach a set size limit in their lifetimes, continuing to grow until they die of natural causes or are killed.
Lobsters grow by molting their hard exoskeleton, and they do so a lot: the average lobster can molt 44 times before it’s a year old. By the time lobsters reach the age of seven, they molt once a year, and after that, once every two to three years, growing larger with each successive shedding of its exoskeleton. The largest lobster on record, caught in Nova Scotia in 1977, weighed 44 pounds, six ounces and measured 3.5 feet in length. Last year, fishermen caught a 27-pound lobster, roughly the size of a toddler–the largest in Maine’s history. For lobsters, bigger bodies translate into more reproductive success: females can carry more eggs as their body volume increases,and they keep producing them until they die.
Molting is a stressful process. Losing an exoskeleton leaves the critter, now without a hard shell and strong pincers, temporarily vulnerable to predators. But predation isn’t senescence. So what would be a natural death for lobsters?
According to Carl Wilson, lead lobster biologist with the Maine Department of Marine Resources, between 10 and 15 percent of lobsters die naturally each year as they shed their exoskeletons because the exertion proves to be too much. Each molting process requires more and more energy than the one before it as lobsters grow in size.
Finally, older crustaceans stop shedding their exoskeletons altogether—a clue that they’re near the end of their lifespans. They run out of metabolic energy to molt, and their worn-and-torn shells contract bacterial infections that weaken them. Shell disease, in which bacteria seeps into lobster shells and forms scar tissue, adheres the crustaceans’ bodies to their shells. The lobster, attempting to molt, gets stuck and dies. The disease also makes lobsters susceptible to other ailments, and in extreme cases, the entire shell can rot, killing the animal inside.
“Is that senescence? Maybe not in how we think about it,” says Jeffrey D. Shields, a marine science professor in the Virginia Institute of Marine Science of the College of William & Mary. “But it is senescence in the way that older people die of pneumonia.”
But one question about lobsters’ lifespans still remains. Scientists do not yet have a truly validated way of determining the age of lobsters. “The problem with lobsters is when they molt, they molt their entire exoskeleton, including their digestive tract and gastric mill and the like, so there are no hard parts that are left,” Wilson says. These hard parts, if a trace of them were left after every molt, would help determine a creature’s age—without them, approximating lobsters’ birth years is difficult.
Previous research has suggested that the biggest European lobster males in the wild live an average of 31 years, and the females an average of 54 years. The work is based off assumed accumulation rates of fat residues found in the creature’s eyestalk. Other scientists are approximating the age of lobsters by measuring a pigment called neurolipofuscin that builds up in the crustaceans’ brains over time. Still more are studying discarded exoskeletons and counting growth bands deposited in the calcified body structures (PDF) to determine an average rate of growth for a given lobster, allowing scientists to estimate its age.
Scientists, however, are not looking for the secret of lobster immortality—it doesn’t exist.
Read more: http://blogs.smithsonianmag.com/sci...bsters-arent-actually-immortal/#ixzz2d9ZLHujA
Follow us: @SmithsonianMag on Twitter''
Well.. wow. I've learned more about lobsters tonight then I ever imagined I could.
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