Animals That are Immortal or Long-lived Animals with "Negligible Senescence". didn't know W/O
Sep 1, 2004 (Updated Sep 10, 2004)
Popular Products in BooksThe Bottom Line Mother asked us to share a little known fact or topic that we know about or have discovered. I looked to the field of science to find my topic.
This in my entry to Mothermeatloaf's I Didn't Know That W/O. Thanks for the invitation, Mother!
What?? Animals that are Immortal you ask. What is Negligible Senescence? Can you believe this has some scientists wondering if human aging can somehow be prevented? This information really brought me to a stand still...
There is an Emerging Area of Aging Research: Long-lived Animals with "Negligible Senescence". Scientists have found that in some animals their aging process is so slow that it is either nonexistent or too slow to be measured reliably in the laboratory. Negligible Senescence is what Caleb Finch, a scientist at USC studying this process, has decided to call this slow-aging or non-aging process. The animals, that exhibit Negligible Senescence, dont have a finite life span like other animals. Which means they dont have a maximum age of life where they would die of old age. They also seem to resist the diseases of old age. They have a life expectancy, or live to an age to which they die of disease, predators, or starvation- but not old age. In this sense, these animals can be considered immortal. Perhaps just as interesting, these animals do not have a fixed body size (such as some lobsters, flounders, sturgeons, sharks, alligators. turtles, and whales) they simply increase in body size with time while showing no noticeable sign of aging.
I know what you are thinking. Let me put your mind at ease... The reason why we dont see 500-year-old alligators the size of houses prowling about is because they have succumbed to the perils of living in the wild.
However, when these animals are kept in zoos free from the external factors that would kill them, they simply grow indefinitely, with almost no decrease of their physical functions- even after reaching full sexual maturity. Interestingly enough, as these creatures get older, they also become more fertile. The egg laying females actually produce more eggs the older they get. Where as in animals that have a fixed body size, fertility diminishes with age as do the number of offspring they produce. These animals usually die soon after becoming infertile as nature has little use for an aging animal well past the vital, offspring bearing age. Such an animal is a drain on the rest of the herd or pack.
Classic examples of species exhibiting both of these traits (mortality and immortality) are the Flounder and the Rockfish. The male Flounder reaches a fixed body size and ages normally, as most animals do, and dies soon thereafter. However, the female Flounder grows indefinitely and shows no signs of aging or loss of function with time. The Rockfish have both short-lived and long-lived members in the same genus. They range from 12 years for the calico rockfish to 205 years for the rougheye rockfish.
Some interesting facts about these Animals with Negligible Sencescence:
Recent research showes that whales can live over 200 years. The Bowhead Whale, which is a baleen whale, may be the oldest mammal on the planet. One has been found to be over 210 years old.
Zoos have also compiled longevity information. Alligators have been recorded up to eighty years of age, although it is uncertain if death was due to senescence or environmental factors. It is expected that older alligators do exist.
Green sea turtles have been estimated to take up to a maximum of 50 years to just reach maturity in the wild. Scientists are still studying and documenting their life span. It is believed that it will be much greater than previously thought.
The Alaska Fish and Game provided data on randomly sampled Yelloweye rockfish, from commercially caught fish off of Alaska. The charts they provided showed that 16% of the fish going to people's dinner tables were 50 years of age or older, with several well over 100 years old.
The existence of animals with no fixed life span seems to indicate that age genes do exist. Apparently, the cells of these animals never lose their vigor or their ability to reproduce. It is the cellular structure and functioning, and the DNA and chromosomes of these non-aging animals that some scientists are beginning to research in hopes of finding the "Fountain of Youth" for human beings.
A German research group found that lobsters produce lots of telomerase and show few signs of aging during their long lives. Telomerase prevents the decay of Telomeres, which caps on the end of chromosomes. Normally, human cells divide about 75 times over a lifetime. Each time a cell divides, the telemere erodes. When this happens, the cell can no longer divide and eventually dies. These scientists believe telomerase has some kind of anti-aging property by protecting cells.
Another study I just found (link provided below) by Dr. Daniel Martinez, Associate Professor of Biology, and Coordinator of the Molecular Biology Program of Pomona University, investigates the role of Telomerase in protecting the somatic cells of the Hydra, which is a type of metazoan. Martinez also believes this enzyme, Telomerase, may be one of the factors in the hydra's negligible sencescence and possible immortality.
The study of Long-lived animals is so new to Aging Research. Many more investigations must be made before anything conclusive can be found. Caleb Finch goes on to say "I think we're pretty far away from finding the answers we are seeking. There are a lot of mechanisms that determine life span. No one is paramount. Even with such studies, I don't expect a quick and easy answer, potion or elixir. I do know we can learn more about aging by studying animals with life spans longer than humans."
There is still very little information on this budding field of study. It will be fascinating to follow along with the research as it becomes more available to the public.
I, for one, have had lots of fun pondering how this will impact our society should scientists actually find the "Fountain of Youth." Just imagine how our economics will be impacted, the psychological ramifications, how medicine and health care will change. Will there be a moratorium on birth? Will we adopt a "death lottery"? How will we deal with a growing population? What about housing, clothing, transportation if we should continue growing? Will this be available only to the rich? The implications just go on and on... But just think-no more bifocal eye glasses or bagging, sagging, wrinkled skin for us oldsters! How and where do I sign up?
Links for further investigation
Here is the link to Hydra: Immortal
(a study by Dr. Daniel Martinez) also be sure to explore the link provided in this dissertation for more information.
A Biography on Dr. Caleb Finch:
Research Project by John C. Guerin- on Centenarian Species and Rock fish.
Cheating Death: The Immortal Life Cycle of Turritopsis
Thanks again to mothermeatloaf of this inspiring W/O.
I hope you enjoyed my contribution.
Thanks for the read,