For mammals like humans, aging is inevitable. No matter how many vitamins we take, the skin hangs, the legs soften and the joints solidify over time. But turtles and turtles age more gracefully. Despite their wrinkled skin and toothless gums, species like Galapagos Giant Turtles seems undamaged by the ravages of aging. Some show few signs of slowing down as they sink into their 100s.
To determine what drives these timeless wonders, two groups of researchers examined turtles, turtles and their ectothermic, or cold-blooded, brothers in a couple of studies published Thursday in the journal Science. Previous aging research has largely revolved around warm-blooded animals such as mammals and birds. But ectotherms like fish, reptiles and amphibians dominate the books on longevity. For example, called salamanders olms glide through underground caves for almost a century. Giant tortoises can live twice as long – earlier this year, a Seychelles tortoise named Jonathan celebrated its 190th anniversary.
IN one of the new studiesResearchers compiled data sets on 77 species of wild reptiles and amphibians including Komodo dragons, garter snakes and leaf frogs. The team used decades of monitoring data to analyze properties such as metabolism to determine their impact on aging and longevity.
“We had these amazing amounts of data to address issues of aging in a way that has never been done before,” said Beth Reinke, an evolutionary biologist at Northeastern Illinois University and author of the new study. “Getting to the heart of the question of how aging develops can only be done with this broad taxonomic strategy.”
Living so long requires a gentle aging curve. After most animals have reached sexual maturity, much of their energy is devoted to reproduction at the expense of repairing aging tissue. This physical deterioration, or aging, often causes an increase in the risk of mortality when older animals become susceptible to predators or diseases. However, several cold-blooded animals experience some aging as they age.
One theory is that cold-blooded animals are better equipped to deal with the wear and tear of aging because they rely on the environment to calibrate their body temperatures instead of energy-draining metabolisms in endothermic or warm-blooded animals. But what Dr. Reinke and her colleagues found was more complex. They found that some ectotherms age much faster than endotherms of similar size, while others age much more slowly. The aging rate of lizards and snakes was widespread but was remarkably low in some crocodiles, salamanders and enigmatic tuatara. However, the only group that barely aged at all were turtles and turtles.
The another new study drilled deeper into the aging of these timeless turtles. The researchers examined age-related declines in 52 species of captured turtles and turtles in zoos and aquariums. They found that 75 percent of the species, including Aldabra giant turtles and pancake turtles, showed low or negligible old age. A few, such as Greek turtles and black marsh turtles, even showed negative aging rates, which means that their risk of mortality decreased as they aged. About 80 percent age more slowly than modern people.
Turtles as an anti-aging standard makes sense, given their sluggish metabolism. Researchers have also linked their robust shells to longer life. When herbivorous turtles and turtles spend their lives munching on vegetables (well, mostly), snug armor provides protection for even grizzled jisses.
These sluggish aging rates are unsurprising given the pampered life of turtles. But unlike humans, who age regardless of the fantasy of cryogenic conservation, captive turtles provide evidence that ideal zoos can slow down aging because reptiles are at ideal temperatures and enjoy a balanced diet of fruits and vegetables.
“We compared the populations in zoos with wild populations and found that under protected conditions they could turn off aging,” says Rita da Silva, population biologist at the University of Southern Denmark and author of the turtle study. “For humans, our environment continues to get better and better, but we still can not turn off aging.”
Although the mortality risk of long-lived turtles and turtles remained stagnant for decades, they have not had eternal youth, according to Caleb Finch, a gerontologist at the University of Southern California who studies aging in humans. Like older people, the sight and hearts of turtles and turtles eventually weaken.
“Some of them get cataracts and are so weak that they need to be fed by hand,” says Dr. Finch, who was not involved in the new studies. “They would not survive in the real world, so there is no doubt that they are aging.”
Although these clumsy reptiles may not surpass death, they may have insights to prolong life and reduce age-related decline.
“If we continue to study the development of aging in turtles, we will someday find a clear link between turtles and human health and aging,” said Dr. da Silva.
#Hundredyearold #turtles #set #standard #antiaging