If you had a time machine and brought a cro-magnon human from 30000 years ago to the present day, could you prove he really was an ancient human?
I’m thinking lack of industrial pollution in his body, different isotope ratios, genetic techniques proving he’s the ancestor of half of modern Europe, that sort of thing. Maybe he could solve some current archaeological riddles as well.
I suppose you could always just ask him. 
“Pardon me, sir, but are you in fact a living example of ancient man?”
Pops into my head immediately–you could test him for lead. Any lead at all, he’s modern (or he’s from Nebraska.)
Perform genetic analysis to establish that he was of European stock. (Thereby ruling out that he could be a member of a contemporary neolithic society.)
Analyze his teeth to see if they exhibit wear patterns consistent with a neolithic lifestyle.
Ask him to make some neolithic artifact – a chipped stone tool, for example – something that only a few contemporary experts can produce.
Examine his intestinal parasites to see if they are genetically different from contemporary worms. (This would be hard to fake.)
Hard to fake unless, of course, you had a time machine. Faux cro-magnon man could go back in time, hang out with the true cro-magnons for a couple years, learning their ways, eating their food, wearing out his teeth. You might be left with only point 1.
But then, if you did have a time machine, why would you bother to fake it?
As to asking him to make a stone tool or whatnot, two problems come to mind: First, his tribe might have only had one or two full-time toolmakers: It’s conceivable that it was a sufficiently specialized task to justify having an expert. Secondly, there’s plenty of modern folks who can still make stone tools… There’s just relatively few academics who can do it.
but what would be the point of a fake cro-magnon if you had the time machine to produce a real one?
Lead is a superb suggestion. Duck Duck Goose, you’re a star! And there was me thinking about transuranics from the nuclear bomb tests and other tricky propositions…
Do you know if modern humans living in very remote areas are contaminated with lead? I suspect that they are, but it would be good to know.
I always felt you could do something useful with genetic testing, but I don’t know enough about it to figure how much you could find out.
Intestinal parasites are another great idea, thanks Pochacco!
So I guess the answer to the OP is “You don’t have to prove it, because why would you fake it?”
OK, how about this: Some high School student grabbed Adolph, (no, too obvious), Hermann Goerring as supporting evidence for his thesis in his History term paper project on the Gestapo. Hermann overpowers the unfortunate student, sends him back in his place, and has taken up a new identity as an historical anthropologist. Being a eugenicist (sp?), he sets out to prove that the Arrayan race was the original race of Europe, so he finds some people he believes are pure, sends them back to 30,002 years ago, then picks them up from 30,000 years ago. He is now parading them around, using them to stir up popular support to send an army back in time to fight for the Reich. Good God, it could be the end of history as we know it! That is, unless you can prove these Arrayan/Cro-magnons are fakes.
And everywhere you go, people always say the same thing: “But what would be the point of a fake Cro-magnon? He has a time machine!”
Hey, it could happen! :eek:
I seriously doubt whether there is anywhere in the world you could find a human population that hasn’t been exposed to lead. The OP is talking about a grown man, I’m assuming, so he would be at least 20 years old, growing up during the years 1980 to today. Where in the world could he have grown up, to have absolutely no lead in his body?
http://ens.lycos.com/ens/jan99/1999L-01-18-01.html
There’s a nifty graph, too–"Global production and consumption of selected toxic metals 1850-1990. Source J.R. Nriagu, Science, Vol. 272 "