> Even as they age, most bird species lack physical signs of getting old—their beaks don’t wrinkle, and their feathers don’t thin out or go gray. “Usually, you can't tell the bird is old just by looking at it,” says Kenn Kaufman, field editor for Audubon magazine. “In a few birds, they'll start to develop more white feathers in the plumage around the head, like a person's hair turning white, but that's not a common thing.” Unless a bird is banded, it’s hard to know its age.
> However, birds still go through the aging process. “The dogma in the field for many years was they don't really age, they just die,” Austad says. “But everybody that has studied them intensively can see some signs of them aging.”
There’s many other phenotypic markers of aging than those that affect the skin. Cardiovascular fitness, muscle function, and eyesight are but to name a few.
As an interesting aside, even if humans didn’t age, our expected lifespan is still on the order of several centuries due to fatal accidents.
The adage is that if we didn’t die of age we would simply not cross the street, the odds may look slim in our short lifespan, but if you extend those to a thousand years getting hit becomes a facto of when, not if
With current population curve (and assumption of yours) states would quickly need to add mandatory accidents due to exploding population.
But imagine skills of those bright people who pushed boundaries of mankind into better places, if they could contribute for say 500 years. Like in Tolkien's world elves attained great mastery ie in smithing over millennia of experience.
In any case it would be horrible for mankind, because there is no shortage of Putins and Stalins in general population and they would burn whole world to the ground without blinking an eye to get closer to immortality. No, thank you, death is a great thing for us even if individually most of us are shit scared of it, and various religions trying to tackle this certainly don't help as much as people would like.
There are plenty of reasons organisms die other than aging.
Accidental death as being cited here is certainly one, but also predation, disease, and intentional killing or maiming that leads to death from other organisms competing for the same resources, whether that be humans waging war, male oxen fighting for breeding rights, lions killing hyenas and cheetahs to maintain dominance over hunting territory, or plants that strangle out other plants to hoard scarce sunlight.
There are also plenty of animals that more or less die on purpose to make way for the next generation. A fair number of insects are designed to only ever go through one breeding cycle, including some that don't even have mouths because they come into adult form with the energy they need to reproduce and no more and that's all they'll ever get. The giant octopus spends a season fattening up so she can stay in the nest tending to her clutch while all of her eggs mature, never leaving and starving to death as she does so.
Life on the larger scale depends upon individuals themselves continually being born and dying to maintain the level of dynamic adaptability that allows life to flourish as local ecosystems and the planet at large change. A programmed maximum lifespan via aging is only one of many ways that happens.
> Even as they age, most bird species lack physical signs of getting old—their beaks don’t wrinkle, and their feathers don’t thin out or go gray. “Usually, you can't tell the bird is old just by looking at it,” says Kenn Kaufman, field editor for Audubon magazine. “In a few birds, they'll start to develop more white feathers in the plumage around the head, like a person's hair turning white, but that's not a common thing.” Unless a bird is banded, it’s hard to know its age.
> However, birds still go through the aging process. “The dogma in the field for many years was they don't really age, they just die,” Austad says. “But everybody that has studied them intensively can see some signs of them aging.”
https://www.audubon.org/news/why-birds-are-anti-aging-supers...