I really like this Slate article by Jon Cohen in which he discovers his not-quite-Cohen-modal haplotype and journeys to South Africa to meet a Lemba. It's old (from 2000), but I will be pointing to it for one of my classes this semester, so I'm noting the link here.
This is great:
Confused, I asked if being a one-step neighbor meant that one of my forefathers had a mutation in his Y, branching him off the tree that represented the Buba clan of the Lemba and other "true" Cohens in his study? "It can't be said exactly that way," Goldstein cautioned, sounding like a rebbe answering a question of Talmudic proportions. "The way that I'd say it that would be accurate won't be very satisfying for you."
I want to remember that line! Then there is his skeptical visit to a South African Lemba:
He introduced me to his wife and three sons, and we sat in his living room, which was free of the religious artifacts of most American Jewish homes -- photos of brides and grooms standing under chuppahs, needlepoints of yarmulke-clad men snapping their fingers in dance, artsy menorahs, and gilded sedar plates.
Probing the Jewish-like "dos and don'ts" of the Lemba, I found as many differences as similarities. Mbelangwa had never heard of the kosher practice of separating milk from meat. Lemba don't celebrate Passover, which is as important a religious gathering to most Jews as Easter is to Christians. He didn't know whether it was forbidden to name a child after a living relative, which Jews aren't supposed to do.
How fragile the ties that bind...