Age - a question for my all-knowing friends-list

[andrewducker]

Ed was asking on Facebook what it would be like if we didn't age visibly so much - after all, other animals don't tend to.

Is this actually true?  Thinking about it, most other animals don't seem to get wrinkled in the same way, nor does their fur turn completely white or all fall out.  But is this just some animals?  Do other animals age visibly the same way we do?  Or is there something odd about people?

Comments

[andrewducker]

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

[drdoug.livejournal.com]

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.)

[andrewducker]

Cheers for that - the photos especially.

[drdoug.livejournal.com]

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.

[drdoug.livejournal.com]

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.