Did you see the video of the tribe in Papua New Guinea singing the Shema Prayer in Hebrew? I found it fascinating!
Are they one of the lost tribes of Israel?
It’s a cute clip, but don't be fooled. Their ability to sing Hebrew songs doesn't make them Jewish. I can sing Awimbawe but that doesn't make me a long lost African. And anyway, parts of that clip just don't add up.
If indeed they were a lost tribe of Israel, clutching to their traditions for thousands of years in spite of their dislocation from other Jews, why do they chant the Shema in a distinctively modern European tune? Why do they sing it in English after singing it in Hebrew? And what is the explanation for the placards they display with English quotes from the Bible?
The explanation is simple. These tribesmen are not performing an ancient rite; they are singing the Hebrew songs that missionaries have taught them.
Jews do not missionize. We don't believe in converting the world to our ways. Non-Jews don’t need to fulfill the 613 commandments given to the Jews. But there certainly is an ethical obligation of monotheism - belief in one G‑d Who expects us to live morally. In fact, this is actually what they are declaring in the shema prayer they are singing, “The L-rd is our G‑d, the L-rd is One.” If you continue your search for this tribe and need some ideas of what to teach, tell them about the Seven Noahide Laws for all mankind.