Disappointed, I wondered if some gene on the Y chromosome provoked intercontinental wanderlust. I reassured Sharif's wife that despite all the chromosome malarkey I was not her husband's unknown American son. His actual son was home, however, and he proudly produced snapshots of his dad. Maybe it's a stretch, I thought, but the man in the photos could pass for an uncle in my family. The Y is a big chunk of DNA to have in common.
History suggests a few possibilities.
Sharif's Tajiks are Persian-speakers who moved east to Samarkand well before the arrival of Islam there about 1,300 years ago and the heyday of overland trade. They mixed with people already there and, later, with Turkic immigrants and others. The common influence of Indo-European, Semitic and Turkic ancestry is one clue to how we might share a recent ancestor. That both Jews and Tajiks plied the Silk Road about a thousand years ago is another. Maybe the DNA gathered on our expedition will solve such little mysteries, along with bigger ones.