:I think you've given me enough info to realize that keeping the material is correct. You simply don't like the conclusion. You can't say, "That source is unreliable, because I don't agree with the theories in it." Similarly, there is no requirement that claims be based on DNA analysis (in fact, DNA analysis is at present a terribly method for analyzing group history, since every DNA study I've ever seen conducted in cases like this in India has been terribly flawed, with too small a source, or too small a conclusion). And, ultimately, neither the book nor the Wikipedia article state that the claim is a "fact"; they state that it is one theory. Our job is to report what reliable sources have said, and so that needs to stay there. It's not a claim about a living person (individual living people fall under slightly more strict rules, but not really groups), and, even if it were, it's not negative anyway. It's simply stating one theory of their descent.