::::I think people are mistaken in thinking that anything published in a reputable source can be considered a reliable source unless it is clear that source has some kind of expertise or reputation for reporting those kind of facts accurately. I do not believe the Guardian/Observer or any other newspaper check statements made about people's ancestry for reliability, therefore I do not believe that they can be considered a reliable source in this context. Only sources that have some kind of expertise and are known to do detailed research should be considered reliable for such purposes (i.e. The Jewish Year Book or Jewish Chronicle).