Reverse Gear writes "Many of the inhabitants of a lonely village in north western China seems to have distinctive western features. An old theory from the 50s suggests that a Roman legion lost in what is now Iran in the year 53BC lost their commanding officer. They traveled east, so the legend goes, working as mercenaries until they were caught by the Chinese 17 years later. The Chinese described them as using a 'fish-scale formation', which could be a reference to the well-known Roman phalanx technique called the 'tortoise'. The remainder of the legion, it is suggested, may have intermarried with the villagers in Liqian. Scientists are now trying to verify the fascinating theory by testing the DNA of the inhabitants of the Chinese village."
If it happens once, it's a bug. If it happens twice, it's a feature.
If it happens more than twice, it's a design philosophy.