Thank you for your reply. It's very complicated and I realise that my brother and I could have received those segments of DNA from either parent. I don't think I'm expressing myself well. Do both our parents have more than one piece of DNA to hand down to their offspring in exactly the same place? If they only have one and not multiple options at the same point doesn't that mean that my brother and I who have completely different Triangulated groups occupying exactly the same place on any given Chromosome must have received that section of DNA from different parents?