Your uncle might have been an Arab-sort of.... The Proceedings of the National Academy of Sciences comes out with this fascinating piece today (if you don't like long-winded academic pdf files-The Indepdent has a good summary of the findings). The conclusion-demic diffusion is not dead, the Neolithic revolution might have resulted in wholesale replacement (or overwhelming) of Paleolithic populations throughout Europe 10,000 years ago. At least in some parts of Europe. It seems that "Europe" really is just an abstract concept-as this article hints that Greeks are predominantly descended from Neolithic farmers from the Middle East while Basques and other western Europeans (and northern) are mostly descended from Paleolithic hunter/gatherers. What it does break down is the idea of a common Mediterranean race-as the inhabitants of Iberia come from different stock than those of the Balkans. The Hellespont did not seem to be that great of a barrier-but I wonder, what about the straits of Gibraltar?