Very cool, if true

They do also have other physical changes in the facial muscle structure and stuff. As someone who has owned dogs all my life, I am quite good at estimating dog ages just by looking at them. They don't go wrinkly per se, but they do sag and stuff.

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That seems a lot more subtle. People lose all of their hair, or all of their hair turns white. I've had dogs pretty much all my life, and that's not happened to any of them.

Sure, you can spot an older dog, but the changes seem a lot milder.

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I think the key word you keep using is "seem". The commenter below is right, it's a perceptual issue: we are more attuned to looking at people and therefore the changes are more noticeable.

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I've never seen a dog go through as massive changes as many people do. The changes are a lot more subtle.

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But the point is that to a dog, the changes we go through will look subtle compared to the changes they go through.

I ought to dig out some photos of Gollum when he was elderly and when he was young.

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I'd be fascinated to see those.

I still think that a complete coat colour change, combined with large patches of missing hair, would be less subtle to a dog too...

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1, a human's entire coat colour doesn't change, just some of the areas of more noticeable hair.

2, a dog which lives to the kind of old age we would expect from a human often does have entire coat greyness. Hence my comment about posting pictures of Gollum when he was young and when he was elderly.

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Other mammals age visibly. We're just not as attuned to the subtle shifts in appearance as we are for people.

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The changes seem much less. Do any other ones change their fur colour entirely, or lose all of it?

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Fur changes are the rule with age. (If the animal lives long enough - see other comments.)

There is a huge impact of species and cultural specificity. It's way easier to recognise different people - from only subtle differences - if you have grown up among people who look like that. (Which for my money is part of why having a diversity of human images around is important - we get better at recognising all people that way.)

But to be fair, losing head hair (and it changing colour) has more of a visual impact on humans, because we've already lost a lot of our hair in evolutionary history, so the change impacts on a bigger proportion of the visible hair. Also, we wear clothes so don't notice that e.g. human males tend to get hairier, not less hairy, in places other than the top of their heads.

Couldn't instantly put my hand on photos, but these ones make the point indirectly (they're macaques of the same age, but illustrating the apparent impact of caloric restriction by reduced ageing effects):
http://www.wired.com/wiredscience/2009/07/monkeylongevity/

(There's plenty of evidence of very similar age-related changes in mammals - especially non-human apes - at the microscopic and biochemical level - a cursory web search turns up shedloads of stuff. But that wasn't your point.)

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Cheers for that - the photos especially.

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You're welcome. I also meant to mention shaving (and other hair removal technologies), which is another significant confounding factor in the perceived hairiness of humans with age.

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Oh, and the example everyone knows is gorillas, of course, where the males get a very dramatic change in fur colour on their back - hence silverback.

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IAWTC.

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henriksdal.livejournal.com

animals in the wild rarely reach "old age" - human natural lifespan in "the wild" is probably only about 30 years old. The higher apes (particularly chimps and apes) do go grey, and do suffer male-pattern baldness with older age, but again, they would not normally reach these ages in the wild.

Other mammals kept by humans do seem to age; Cuddles is nearly 17 and looks a lot "older" than he did when he was 10. Dog owners will notice the same, and I would presume, for mammals at least, zoo workers would be able to point out similar aging.

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The higher apes (particularly chimps and apes) do go grey, and do suffer male-pattern baldness with older age

Aha! Thank you.

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fjm.livejournal.com

Not all humans age all that visibly. There is a huge difference in the way people look at age 60 in terms of their ethnicity. As one (very pissed off) friend shared with me, when people tell us 'oh, you don't look your age" what they are inadvertantly saying is "you aren't Anglo Saxon/Celt".

I won't have wrinkles at 60.
I won't be grey at 60.
I will probably be fit and active at 60.

Also: animals don't seem to age because their life span is not artificially extended. As

henriksdal notes above, when it is, then their aging patterns are more like that of us age-fighing humans.

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My parents are both Jewish, and my mother is white-haired, while my father's hair is doing well at vanishing. My hair is going grey around the edges, which will presumably continue.

I know it's not true of everyone - but I've seen wrinkled, bald older people from a variety of cultures. Not that it's universal as a pattern, but it does seem quite pervasive.

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fjm.livejournal.com

How many 60 year old Africans do you know with grey hair? Tends to take a *lot* longer.

And how did your parents look at 50 compared to non-Jews?

I will go grey, but no where near as early as my "english" contemporaries.

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My mum went grey at age 25. One of my cousins decided to be stereotypical in one way by becoming a banker, but clearly not in another by losing 90% of his hair before hitting 30.

My family do look pretty good - but not signicantly better than other middle class people of similar ages I share an office with. Mind you, one of them is of Jamacain origin, and while bald, not wrinkled, which gives you a data point!

The couple of members of the family that _do_ look more aged are the ones that smoke(d). In my experience it's things like smoking/drinking that seem to cause people to age faster - and seems to be more a class thing than an ethnic thing (it's fascinating that certain areas of Edinburgh have groups that look decidedly older, based almost entirely on income/clas).

But I'd be delighted to know that my status as God Chosen is going to keep me looking younger longer :->

Any research into this that you know of?

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fjm.livejournal.com

Smoking definitely throws things off kilter, and my mum started to look a lot younger within three years of giving up.

Prematurely grey hair in women is often to do with a hormone imbalance and is connected to fertility. It's a bad sign as is often linked to osteoporosis.

I don't know of any research, just a general awareness: I teach at a very multi-ethnic university and one learns to be very, very wary about judging age.

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I'm going to be a lot more conscious about that one now - I'll keep an eye out!

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erindubitably.livejournal.com

I'd imagine there's something about social structure and visual clues in there as well - animals like humans and chimps that tend to live longer and live in groups may show visible signs of aging as that inspires other group members to care for the older ones, whereas other types of animals -don't- want to broadcast their age, as it would allow predators to pick them out more easily.

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In summation (assuming the obvious points have already been made in other comments)

1. Human Chauvanism. Of course we think that we age more visibly then other animals!

2. Relatively we live longer. For a fair comparison with animals we'd have to control for age.

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1) How many other animals change their hair/fur colour signifcantly in old age? I've now seen evidence that some do - but most don't seem to.

2) Relative to what?

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1) How many accumulate more scars, does their skin become less firm and wrinkly. Are you sure your not just taking the fact that human hair goes grey as a measure because of human chauvanism? What other signs are there that animals have aged that perhaps are that salient to humans? Probably more then one might think?

Actually the question of whether animals can tell how old another member of their pride/herd/whatever is fascinating. Does it affect mating choice for instance? Hmmmm...

2) Well there is a decision to be made there. Animals (in general) have far shorter life spans. A probably arbitary decision would have to be made as to how long an animals life relates to a humans. IE dog years being considered to be seven years compared to humans.

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Are you sure your not just taking the fact that human hair goes grey as a measure because of human chauvanism?

I'm taking it as an obvious _visible_ change. Dogs do go a bit greyer around the face, and I can spot old dogs from young ones, but the changes do not seem as obvious as large chunks of hair not being there any more, or complete colour changes.

A probably arbitary decision would have to be made as to how long an animals life relates to a humans.
And if you used this factor then animals wouldn't live "relatively" shorter - because your factor would be the same in both cases, surely?

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Depends on differences between domestic and wild type life spans. You could perhaps work out how domestication has increased/decreased life span for certain animals by comparing wolf/dog cow/buffalo (or similar) etc. Then perhaps coming up with a rough approximation for some sort of way to measure ages relatively. But like I say arbitary.

?I'm taking it as an obvious _visible_ change.

Yes, obvious to humans. It's a no-brainer that we'd notice ourselfs ageing more then other species. As it's perhaps an indicator of fittness. What would be interesting would be to explore whether or not animals can detect age in members of their species. As this could indicate either way whether there are "obvious visible changes" or obvious changes involving other senses that make age salient for animals but not for humans.

Otherwise we are just talking about the subjective human experience of not noticing animals get older surely?

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Hang on, are you saying that dogs won't notice the colour of another animal changing?

If I took a poodle and dyed it purple, then all of its poodle friends would fail to notice that anything had happened to it?

That seems...unlikely to me.

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No. That's the round trip fallacy at work there.

I am saying that it's likely that ageing does occur in other animals but that, to our eyes, it occurs more subtely then we might notice but for members of the same species it is noticable. This is testable in various ways - observing the mate choices of a group of animals and relating it to age. Is age a factor in mate choice? Are young mates preferred over older mates for example. Although there will be confounds and age probably turns out to be a proxy for physical strength.

Arguably predatory or scavenging animals would be predisposed to noticing other animals ages but I'd hazard a guess and say that it might be less important for grazing and other herbivorous animals to gauge the age of other animals. Although that doesn't explain why we would be bad at noticing age in other animals so the hypothesis seems crucially flawed from the get go.

Has anyone done any research to suggest that dying dogs hair affects how other dogs relate to them? I would perhaps suggest that a better example would be dipping a dog in some noxious perfume or other might be better...

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Absolutely. I agree it's likely (although not certain - if animals tend to die before they get too old to mate successfully then there's no reason to be able to spot it) - but this is the reason my original post was specifically asking about _visible_ signs, because humans do signal it visibly, and I was wondering why it wasn't quite so visibly obvious in other animals.

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http://www.senescence.info/nature.html

That link may of interest be

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Cheers - will check it out when I'm at home!

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Haven't had a chance to read through it all but it looked quite interesting from a brief browse.

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cangetmad.livejournal.com

Hmm, I can judge ages (as in baby/ young adult/ old adult) with dogs and birds relatively easily, and those are the animals I've had most up-close dealings with (aside from humans). So ITTA with the people thinking it's about familiarity, at least in part.

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rhythmaning.livejournal.com

Others have probably said this, but I believe we age because we don't die at relatively young ages. I can't remember the precise ages, but the average lifespan used to be somewhere in the 40s - although that included high infant mortality, too.

Other animals I think do age (think of elderly cats and dogs - which would probably have died long before had they not been in relationships with humans); and they don't live long past their reproductive lifespan.

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In which case we'll have examples in zoos of older ones...

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cybik.livejournal.com

Except that we don't, necessarily. We don't give animals the same care that we give ourselves. Elephants are put down if they have severe arthritis (I got that factlet from the recent animal autopsies on C4!), for example, but we'd replace joints in humans. Even animals in houses aren't super long lived - how often do you hear of a 30 year old cat (and that is perfectly possible - the WR is 36 years, and my mum knew a cat who was about 35 when he died [after a life of steak and salmon, apparently!])? Not often! Despite it being possible to extend animals' lives as we do our own, we don't tend to do it. We not only have better end-of-life care, we have better life-care throughout our entire lives, which means we're better prepared to live for longer.

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rhythmaning.livejournal.com

And I would say we do - aged bears, lions, elephants: a whole menagerie!

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