says Razib Khan in a survey article with lots of links. I do not understand lots of it and am keeping it mainly for future reference and links. Family systems of Emmanuel Todd are not mentioned in the discussion.He has a later article The Aryan invasion was not fantasy. I usually think in terms of migration. The author seems to be thinking in terms of cultural dominance. Even this is not clear to me except perhaps in many of the languages that are current in India. What evolved including religion, myths etc seems to be a combination with indigenous elements. I do not know which are more dominant but tend towards indigenous elements.