Quote Originally Posted by OC Richard View Post
It's done with ancient human skeletons, you can find out where a person was raised.

This has, for one thing, opened our eyes to the mobility of people within the Roman world.

A Roman cemetery in York revealed that people were from North Africa, Syria, all over the Empire. (York was the capitol of the Roman Empire at one point.)

Another cool thing is that by analysing teeth of archaic humans we can trace waves of Bubonic Plague going back tens of thousands of years. And that inner-ear bones are exceptionally DNA-rich allowing us to do full-genome sequencing of Neanderthals, Denisovans, and modern Humans also going back tens of thousands of years.

A lot of these breakthroughs are only a decade old.
When Peter MacDonald corrected my misunderstandings about the tartan history exhibit at the design museum in Dundee (it was NOT a permanent part of the museum's offerings, partly because some of the pieces were on loan from other owners), he also corrected my misunderstanding of the techniques used to sort out where the sheep who donated the coats off their backs for the Glen Affric weave did their grazing, and matching that to collagen samples from sheep living in different areas. It was based on isotopic analysis of the carbon isotopes in the cloth, NOT on DNA sequencing. I need to look into that more, because I have NO understanding of how precisely that can identify a region. I know the grass in Las Vegas (in the few places where it's not illegal to have a lawn not manufactured from plastic) differs from the grass abundant in Sonoma County and the Montana rockies, but I have a LOT to learn about how it's done and how precisely it can identify regional origin.

I suspect isotopic analysis may well have been among the tools used to dispel the nonsense in the "eat for your blood type" fad.