As the genetic data accumulates, there is more evidence showing that modern Greeks are genetically similar to the Ancient Greeks of Homer's and Aristotle's time.
People find this hard to believe, because Greece has been a crossroads of trade and war for a long time, so there had to have been genocidal levels of mixing. However, kinship has resilience. People will mix, but the core stock remains evident even thousands of years later.
The dynamic of population crises is always toward preservation of the founding stock. Irretrievable population turnover occurs when one tribe completely wipes out the other.
Others balk at these findings because they wonder how modern Greece can be such an economic basketcase while the Ancient Greeks were so smart and wise.
That's a more interesting question, answered perhaps by the idea that small pockets of extreme genius can crop up every so often within a genetically related population.
