Your two main points are exactly what I was implying. 1) Family membership can be clouded by the circumstances. There can be more going on than what we normally think of a family lineage....which includes sisters, half-siblings, adoptions, slaves, infidelity, debt-service and barters. 2) As for my insistence of mitochondrial DNA...it is precisely because they are followed from the MATERNAL side that I believe it is more accurate. Studies have shown that up to a full 10% of children born worldwide were not raised by their biological fathers...even though they thought they were. Perhaps the mom slept with the proverbial milkman or mailman etc etc etc. But children almost always known who their mother is...outside of the rare "switched at birth" occasions.