Not all immortal beings come to us from Hollywood. In the same league as Peter Pan, Dracula and The Highlander, nature’s real-life examples of immortal beings include the turritopsis nutricula. This fairly small species of jellyfish—at 0.18inches—may be the only animal in the world to have truly discovered the fountain of youth. It can cycle from a mature adult to an immature polyp stage—its first stage of life—and back again. We do not know whether turritopsis nutricula retains any memory, or if it goes through an endless cycle of brainless regeneration—much like Hollywood's creations. It could be using its own body to provide the nutrients for a new being. The same mistake was made by French eugenist Alex Carrel, the Nobel prize winner in 1912, when he kept chicken heart cells alive “indefinitely” by feeding them stem cells.
The modern crusade to find immortality continues. However exciting turritopsis nutricula might be for biologists, it does not stir the hearts of modern Americans, who are accustomed to drawing their inspiration from fictional ideals. Besides, immortality has one simple problem to surmount, but it is a big one--physics.
One of the few all-encompassing laws in biology, which is determined in turn by physics, is Kleiber's Law. Max Klieber, a Swiss agricultural chemist, predicted that mass determines metabolism, and metabolism determines longevity. Larger animals live longer.
Kleiber’s Law, however, was complicated by Caleb Finch from the University of Southern California who, while researching aging among animals, found "negligible" aging among rougheye rockfish (who can live up to 205 years), sturgeon (150 years for females), giant tortoise (152 years), bivalves and possibly lobsters. These included no observable age-related increases in mortality rate or decreases in reproduction rate after maturity, and no observable age-related decline in physiological capacity or disease resistance. Finch coined the term "negligible senescence" to describe very slow or negligible aging. But these are just freaks of nature, exceptions to the rule. Or are they?
All this was changed dramatically by a little known experiment in the 1970's. Michael Rose began manipulating the life spans of fruit flies. He allowed fruit flies to reproduce only at late ages. This forced researchers to pay attention to the survival and reproductive vigor of the flies through their middle age. The flies evolved longer life spans and greater reproduction over the next dozen generations. This demonstrated that a “death clock” exists in each of us--which nature can re-set to give us a better chance of reproducing.
This is the kind of stuff that scientists can manipulate. And that is exactly the work done at UC San Francisco by Cynthia Kenyon--who by manipulating genes in the flatworm nearly doubled their life span. These long-lived worms still looked and acted younger than their control group brethren. This changed the way we think about aging on two counts. First, that a death clock exists that can be modified by manipulating genes, and second that longevity is associated with being healthy.
Ageless animals have thought us that there are two ways to live longer: increasing the lifespan and slowing down the aging process. Individually all we can do for now is to try to not accelerate aging by excessive behaviors.
The modern crusade to find immortality continues. However exciting turritopsis nutricula might be for biologists, it does not stir the hearts of modern Americans, who are accustomed to drawing their inspiration from fictional ideals. Besides, immortality has one simple problem to surmount, but it is a big one--physics.
One of the few all-encompassing laws in biology, which is determined in turn by physics, is Kleiber's Law. Max Klieber, a Swiss agricultural chemist, predicted that mass determines metabolism, and metabolism determines longevity. Larger animals live longer.
Kleiber’s Law, however, was complicated by Caleb Finch from the University of Southern California who, while researching aging among animals, found "negligible" aging among rougheye rockfish (who can live up to 205 years), sturgeon (150 years for females), giant tortoise (152 years), bivalves and possibly lobsters. These included no observable age-related increases in mortality rate or decreases in reproduction rate after maturity, and no observable age-related decline in physiological capacity or disease resistance. Finch coined the term "negligible senescence" to describe very slow or negligible aging. But these are just freaks of nature, exceptions to the rule. Or are they?
All this was changed dramatically by a little known experiment in the 1970's. Michael Rose began manipulating the life spans of fruit flies. He allowed fruit flies to reproduce only at late ages. This forced researchers to pay attention to the survival and reproductive vigor of the flies through their middle age. The flies evolved longer life spans and greater reproduction over the next dozen generations. This demonstrated that a “death clock” exists in each of us--which nature can re-set to give us a better chance of reproducing.
This is the kind of stuff that scientists can manipulate. And that is exactly the work done at UC San Francisco by Cynthia Kenyon--who by manipulating genes in the flatworm nearly doubled their life span. These long-lived worms still looked and acted younger than their control group brethren. This changed the way we think about aging on two counts. First, that a death clock exists that can be modified by manipulating genes, and second that longevity is associated with being healthy.
Ageless animals have thought us that there are two ways to live longer: increasing the lifespan and slowing down the aging process. Individually all we can do for now is to try to not accelerate aging by excessive behaviors.
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