As mentioned in the CS Cheeta thread, the “actor” who played Cheeta the Chimp in the Tarzan films is still alive at 76 (the last really major film star of the 30s probably). That’s the equivalent of well over 100 for humans- in fact it’s probably the equal of more than 130 since he’s the oldest chimp every authenticated by more than a decade and the oldest human ever authenticated was over 120.
So, here’s a relatively recent picture of Cheeta. You can look at it and tell that he’s old, and he does have a lot of gray hair, but if a super centenarian male human, if he had any hair at all, would probably be completely white haired. Other elderly apes , same story- their hair turns grayer (though they still have a lot of black as well) but (Snowflake excepted obviously) their hair doesn’t turn white.
I have known some humans like this- if they were originally brunette or dark haired they reach great age with some gray but also some still the original color, and of course some people like Anderson Cooper go gray by 30 and others who do gray don’t start until they’re twice that or more, but the majority of humans, regardless of gender or race or lifetime stress level or geographical location or whatever- start graying in middle age and usually have all white hair by the time they’re very very old. Many if not most would have white hair by the time they’re Cheeta’s age not translated into human years.
What’s different in our hair pigment and that of other primates that causes this? Is it related to what makes humans have less body hair and a wider spectrum of hair colors/textures?
No medication wagered on the answer, just curious.