I have heard that a parrot can live up to 140 years and a average lifespan of human(they live a protected life in a groups) can’t live that longer what’s the reason. what does the lifespan of the organism really matters upon. Not only parrot but Banyan tree (upto 200-300 years) and they don’t even show a single sign of senescence ( deteroiration with age) , Tortoise ( estimated 200 years), Turtle(average is 80 years because of environment at sea but oldest of them is about 400 years). Sure there are some more examples lifespan of queen ant is up to 15 years as long as your pet dog lived(maybe). what does life span really depend upon . Does life span means that living efficeintly, being able to heal or replace the cells if necessary? What’s your opinion about it . Does lifespan really depend on nothing or something?
Not really an opinion, maximum life span is rooted in biology. Definitely depends on “something”, not nothing.
Here is a free journal article about the study of why life spans are the way they are in different organisms: https://journals.biologists.com/jeb/article/208/9/1717/9377/Body-size-energy-metabolism-and-lifespan
Here is a more reader friendly discussion by BBC Earth http://www.bbc.com/earth/story/20170330-the-tricks-that-help-some-animals-live-for-centuries
One of the big determinants is how vulnerable the organism is to dying of “natural causes.” For example, smaller, poorly defended animals (like mice or insects) are more likely to die fairly young due to predation, so it’s not useful for them to repair their body as carefully. They are better off investing their energy into reproduction now.
Flying species like birds and bats, which can escape predators more easily, often evolve to have longer lifespans than similarly sized non-flying mammals, even in the absence of predators. Avoiding aging is more likely to pay off for these species. Likewise, well defended turtles live much longer than comparable lizards. Even within species, populations subject to less predation (such as on islands) tend to evolve to live longer and age slower than their relatives on the mainland.
Unfortunately, we don’t know exactly what’s going on in the body of a plant or animal when it ages - it’s probably a bunch of things all at once! Once we get a good undestanding of that, we may be able to adjust our own physiology to increase human life-span (and health-span) beyond what is possible today.
Animals that live long periods of time with limited and unpredictable supplies of food, such as cave animals and deep sea fish, can live extraordinarily long lives. There are cave crayfish that live past 150 years. This is due to having very slow metabolic rates. A Greenland shark also takes 150 years to reach sexual maturity.
Like most of the comments so far, it depends! I don’t know why parrots live so long, but it must be a combination of genetic and environmental reasons. Some invertebrates have a sort of built in life span - moths don’t live for much more than two weeks. Some have no mouthparts and live a few days. Some cicadas can live underground for 17 years. I don’t know what the genetic mechanisms are, but certainly adverse weather and predation can shorten the life of even long lived species. The need to generate heat (homeothermic), like mice, usually shortens the life of smaller organisms, and cold blooded organisms (poikilothermic) generally live longer. But with anything in biology, there is always an exception!
Simple evolutionary trade-offs! and it is certainly not based on nothing. Alot of it is based on reproduction. For animals who have high risks of predation, think rabbits and even smaller frogs and spiders, It doesn’t ‘pay off’ to have long life spans and take a long time to reach sexual maturity. Any second one of them could be snatched up by a predator. So evolution’s ‘fix’ to this is okay lets speed this process up lets reach sexual maturity relatively quickly, like within the first year of life, and lets also make hundreds of babies (as seen in spiders and mantis for example). This simply increases the odds that atleast some of them will survive to sexual maturity, knowing most will not.
As for why humans can’t possibly live that long YET ;) … Even with our elite healthcare that other animals don’t have access to, biologically our bodies are simply not constructed to withstand that life span and all the health problems that would come with the break down of our bodies’ essential systems. Throughout our own evolution we’ve more than doubled our average lifespans as we’ve advanced from cavemen to modern day humans with our elite modern health care abilities capable of curing diseases so easily that would kill a caveman within days with no chance of recovery. Although our improvements are large they are not infinite, and we are still bound by the limtis of biology, so some may argue we are approaching our capacity to extend our lifespan further. Sure in our lifetimes we may see someone reach 140 years old, but is in unlikely, and we are probably 500 years away (if we last that long lol) from seeing our average lifespan ever even approach that number.
You also have to look at what an animal’s actual lifespan is. Yes, some species of parrots can live up to 140 years.That doesn’t mean that they all live to be 140, or that a majority of them live to be 140, even excluding those that die of predation and disease.
It would not be untruthful to say that humans can live to be 115. Some 50+ documented people have lived to at least 115, and that list would be longer if someone could access a table of all the humans to have ever lived.
The common housecat is known to live up to 25 years. That doesn’t mean that a cat which dies of old age at 15 years is in any way notable. 15 years is a long time for a cat to live, and some exceptional individuals have lived much longer.
One way of measuring a lifespan is by number of heartbeats. In a sense the number of heartbeats is an approximate measure of the ‘experienced life’, as it corrects for faster and slower metabolisms. This means that a tortoise 200 years will not feel as long as our 80 years to the tortoise.
On this measure, human beings have an unusually long life with 2.5 billion beats per life. The average for mammals is 1 billion beats per life. http://robdunnlab.com/projects/beats-per-life/.
I think that some animals have evolved special tricks to beat the 1 billion beat per life (which we have done) like the naked mole rat.
The scientific field of Evolutionary Demography, in which I have published and taught, has produced many versions of this question, and even more answers. Having read almost all the available literature on this, I am confident in saying that there is no short satisfying answer yet available. The mechanisms that influence lifespan (ecological, genetic, evolutionary, etc.) are so diverse, and the circumstances of the many organisms so diverse that every attempt to generalize has severe limits and counter-examples.
Population biologist speak of r-adapted and K-adapted species. Of course many, perhaps most, species are somewhere in between these two strategies. Basically, r-adaptation means produce hordes of offspring which mature very quickly; it tends to be found in species subject to high predation pressure. K-adaptation means invest a lot of energy into raising and protecting a few high-quality offspring; it tends to be found in species that live in numbers close to their habitat’s carrying capacity. A side effect of this is that r-adapted species will have short lives, K-adapted species will have long lives.
Thanks that helped
Now by reading all your replies ,Is it safe to conclude that their are several factors which affect life span
- slow metabolism
- predators (environment)
- body mass(size)
But all of the factors are not inter- related and all have contradiction.
and humans have longer life as compared to other animals as they have most heartbeats(2.5 billion beats per life) which means they have both higher metabolism are not small in size.( please correct me if i am wrong
Can you tell me whether I have answered last point correctly
I think @dlevitis summed it up pretty well - there are just too many factors to come up with a short answer. Genetics, metabolic by-products, gene repair ability all play a part too. Here’s a Wikipedia article about some of the genetics of aging - Genetics of aging - Wikipedia. If you can understand most of it, you are a better person than me! The BBC article from @antrozousamelia is also a very good primer.
Oh, there is also pre-programmed cell death/apoptosis which is also a factor. Apoptosis - Wikipedia. Again, take a deep breath before attempting to understand it!
In fact not really, K and r strategies are only applied when you compare different groups, then there’re many groups, like turtles, that don’t look after offspring after laying eggs, but live a long life, those strategies depend on how many youngs die, adults can have both long and short lifespawn, as others said metabolism rate is first thing to look at.
I feel like this statement summarizes the entire field of Biology. 
I know this to be true since I study Biology.
So according to this, if we humans keep ourselves from dying from anything but old age, then we will eventually evolve to live longer?
Probably not. Evolution works based on how well you pass on your genes (how many offspring you have). Many organisms can continue to produce offspring into old age, which means that living longer could be really beneficial in a relatively safe environment.
It’s different for humans because of menopause, and also because our cultural norms around families. Most people have kids in their 20s or 30s (even if they could theoretically have more later), so the aging process has very little impact on what genes are passed on. There was a study several years ago that reported that American women are evolving to have later menopause, as this increases their likelihood of having more children, but the change was very slow: about one month per generation, on average.
Welcome to the forum!