No real surprise here

So, the Crusaders left a 'genetic legacy' in the Middle East? Colour me decidedly unsurprised. The Crusades weren't simply a string of military invasions: after the first crusade, the crusaders had made such territorial gains that a series of crusader states were established in the Levant. The longest-lived of these (Jerusalem) lasted until 1291. These were finally reconquered by the Arabs, but by no means were they extinguished. As with most of the Islamic conquests, the leadership was simply replaced and the people progressively converted.

So, given that there was a permanent crusader presence in the Levant for two hundred years, and that this presence was assimilated rather than extinguished, why shoiuld there by any surprise that their genetic heritage is still there? After all, when they found a pre-historic man in Somerset, his direct descendant was found to be living in the next door village.