Jeanne Calment is nothing on Creme Puff the cat. The oldest living human is at the ripe age of 122 not bad for a species with an average life of 71 years. But Creme Puff, a feline Texas that would have existed on the bacon, broccoli and thick cream, more than double the longevity of its kind, Surviving 38 years reported. Bluey, an Australian cattle dog, was no slouch either. At 29, he became the oldest recorded dog, living more than two times longer than the average dog.
For centuries, scientists have tried to understand the duration of human life. What sets the limits? What can we do to slow the clock? Now they are beginning to ask the same questions of our pets. As with humans, the answers were hard to find. But some interesting hypotheses emerging ideas that can help explain everything from why small dogs live longer than large why cats tend to last longer than our canine friends.
Understanding how animals age is a "fascinating problem," said Daniel Promislow, an evolutionary geneticist at the University of Washington, Seattle, and co-leader of the project Dog aging, which aims to prolong canine life. "It incorporates the behavior, reproduction, ecology and evolution. If we can understand how to improve the quality and duration of life, it is good for our pets and it is good for us. He is a winner -win. "
sCIENTISTS WERE meditating mysteries of aging for over 00 years. "The reasons why some animals are long life and other short-lived, and, in a word, causes the length and brevity of the appeal of life for investigation," wrote Aristotle 350 BCE the Greek philosopher suspected the answer had something to do with moisture: elephants survive mouse, he reasoned, because they contain more liquid and therefore take longer to dry the idea has not exactly. held water, but the observation of Aristotle that larger animals tend to live longer has. Indeed, it is the only scientific trend today agree.
"All other assumptions have fallen apart," says Steven Austad, a biogerontologist at the University of Alabama, Birmingham. One of the most popular ideas of the last 100 years has been that animals with higher metabolic rates live shorter lives because they go to their body clock more quickly. But "he did not stand up," says Austad. Parrot hearts can beat up to 0 times per minute, for example, but they survive by decades many creatures with slow tickers. Other assumptions, such as acute animals generate more free radicals damage tissue or have cells that stop dividing before, also lack solid evidence. "Many simple stories have disappeared," he said.
(chart) A. Cuadra / science (Data) Anage
Austad should know about thing about animals. He worked as a lion coach in the early 1970s, until one of the big cats tore his leg injury that persuaded him to study, rather than tame, the creatures of the world. in the mid 1980s he was observing the behavior of opossum in Venezuela as a postdoc when he began to notice how quickly marsupials older. "They're going to be in great shape for cataracts and muscle atrophy in three months, "he said. Austad also noticed something even more intriguing: possums on a nearby island free of predators appeared to age more slowly and live longer, their mainland counterparts
The observation has helped explain why a key insight Aristotle continues to be true .. large animals tend to live longer, Austad said, because they face less danger. This is not a simple matter of survival, he said, but rather the result of millions of years of evolutionary pressure. Whales and elephants can afford to take their time growing because no one will attack, he said. And that means they can invest resources in solid bodies to enable them to produce many offspring cycles. Mice and other prey heavily on small animals, on the other hand, live life in fast forward: They need to put their energy into growth and rapid reproduction, not in the development of hardy immune systems, Austad said. "You would not put a $ 1,000 crystal on a watch for $ 5."
WHEN IT COMES TO OUR ANIMALS , the largest-is-better theory turned on its ear. The cats live on average 15 years, compared to about 12 for dogs, despite being generally smaller. And the dogs can live twice as long than large.
Yet the lesson of Austad of opossums may still apply. Gray wolves, the ancestors of dogs, live up to 11 or 12 years in the wild, while feral cats can live up to 16 years. This suggests that the two species face different pressures of evolution, says Austad. The wolves are more social than cats and therefore more likely to spread infectious disease, he said; wildcats, on the other hand, keep to themselves, reducing the spread of disease, and are able to defend themselves against predators. "Cats are so incredibly well armed, they are like porcupines" -an animal who notably also a long life for its size, more than 20 years. Indeed, two other small animals that are good to avoid danger, rats and bats naked moles, can live 30 and 40 years, respectively. (Mole Rats spend most of their time underground, while bats can simply fly away.) Mice, meanwhile, only live a few years unless they eat first.
David Hedges / SWNS.com via Guinness world records
Poppy, recognized as the oldest cat in the world in 2014, lived to the ripe age of 24.
regarding why small dogs tend to survive large, the story gets a little more complicated. Large dogs like the 70-kilogram Irish Wolfhound have the chance to get to 7 years, while tiny pooches like Papillon 4 kilos can live 10 years longer. Most dog breeds are at least two hundred years the pressure, so that evolution is clearly not at work. Instead, hormones such as insulin-like growth factor 1, which inflates the dogs to great heights, can play a role; Researchers have linked short-lived protein in a variety of species, although the mechanism is unclear. Large canines also tend to grow faster, Promislow note of Aging Dog project, which could result in "jerry-built" of the body that are more susceptible to complications and diseases. Large dogs tend to have more health problems than those German shepherd children are prone to hip dysplasia, for example, and Siberian Huskies are plagued autoimmune disorders, although these could also be the result of inbreeding.
Despite differences between cats and dogs, two animals living longer than ever before. Dog life expectancy has doubled in the last 4 decades, and housecats now live twice as long as their wild counterparts. The reasons can largely be chalked up to better health care and better nutrition. Americans will spend $ 60 billion on their pets this year, with much of that going humanlike health care (think annual physicals and open heart surgery) and premium food. "The same things that allow us to live longer also apply to our pets," says João Pedro de Magalhães, a biogerontologist at the University of Liverpool in the UK Anage maintains the largest database in the world animal life covers. The trend can not continue, if :. More than half of US pets are overweight or obese, and they are exposed to the same pollutants and carcinogens that we are
All this sets only dogs and cats to solve the riddle how we age. After all, we have over medical records on them than on any other animal save man, and we are learning more about their biology and genomes every day. Perhaps they hold the clues to slow down the body clock for us all and maybe even stop it. "I do not think there's a nuts. longevity for all species. ", says Magalhães" The real question is: "How far can we go? Perhaps a thousand years from now you might have a dog that lives 300 years. "
This is good news, especially if our lifespan increase dramatically as well. After all, who wants to live forever if you can not live with your best friend
for more information on aging :?
- Feature: Death defying experiences
- Feature: the countdown
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