Ted, Harriet, Marian and others, Why I will be happy to answer some questions I still am not an expert on the subject. I can send you to the site I have been using and you can find many of the answers to your questions there. I will say if you ladies have a brother you might want to have him tested instead and share the cost. He will have the mtDNA of your mother's group and the Y chromosome of your father's group. If your brother has children all the boys will continue to have the same Y Chromosome and continue to pass it on in the males. Mutations in both female and male lines do occur on occasion and are also part of how these groups can be determined. Again back to your brother and any girls he fathers will have the female mtDNA of his partner and she will have received it from her mother and be passing it on to her female offspring and continue it on down. My cousin has the all direct female lines back to the female ancestor that I mentioned before. My father had that X passed to him but was no longer alive and his deceased sisters also carried it and it continues to be passed on as long as the females in that line keep having females. Marian, I have been trying to sit on my hands till the results are in and I could surprise with the news as we all share the same ancestor even though we could not be tested for that particular X. Below is the group I have used for all my testing. Family Tree DNA http://www.familytreedna.com/ I hope this will answer some of your questions. Take your time. Also check your library for some books on the subject. Jo Anne