Not sure if this is the right sub for this, but it doesn't seem to break ny rules, so here goes.
I've heard some interesting stories about the native people of some Pacific islands who tell stories of small, hairy ape-like men who once lived there. Apparently, some historians believe this could refer to a protohuman species which co-existed with humans tens of thousands of years ago. This seems like a bit of a stretch to me, considering how (relatively) quickly myths and religions seem to change over time. However, have there been any studies on how far back oral tradition can be considered accurate?
There have been such studies! https://theconversation.com/ancient-aboriginal-stories-preserve-history-of-a-rise-in-sea-level-36010 is just one of many examples. In this case, oral history has been verified to accurately record events going back up to 18000 years, and there are other stories referencing megafauna and migrations that appear to refer back even further. In North America there are similar cases of oral histories relating environmental change and states, or historical geological events, going back to the ice age, including stories of megafauna, sea level changes, the end of the ice age, and changes in climate.
The main issue here is that western approaches to oral history have always taken their own storytelling practices as assumed standards, and then evaluated shifts and changes over time accordingly, while many othe rcultures of the world have much more consistent methods of knowledge transfer.