Sure, there are plenty of such populations. The first one that comes to mind is the Kogi, who live in a sky island 4000 meters above northern Colombia: https:/

Sure, there are plenty of such populations. The first one that comes to mind is the Kogi, who live in a sky island 4000 meters above northern Colombia: https://en.wikipedia.org/wiki/Kogi_people https://en.wikipedia.org/wiki/Kogi_people But none of those populations can actually be used for testing, because you would need to collect relevant data on them starting 50 years ago, and we don't have any time machines.