It's important that we learn about this so we don't repeat it. Sadly, we are repeating it. Perhaps it's impossible to prevent the cycle because it can only be prevented by those who benefit from it.
http://www.stat.yale.edu/~jtc5/papers/CommonAncestors/Nature...
> Chang established the basis of this research in a previous publication with an intentionally simplified model that ignored such complexities as geography and migration
This seems like a very impactful simplification. Especially given the relative limited mobility of peoples up until very recently.