Bill- A brother and sister wouldn't have identical autosomal DNA. Full siblings inherit 50% of their DNA from their mother and 50% from their father but it may not be the same 50%. They would match closely -- their mtDNA would be the same. The brother would carry an X chromosome from his mother and the sister would carry one X from the father and one from the mother. The brother would carry a Y from his father...so there would be differences there. To explain about autosomal genes in another way...we each carry a dominant and recessive for each gene---and we can pass either our dominant or recessive on to a child. So one sibling might inherit the dominant gene and the other the recessive. Dominant and recessive help to explain why one sibling might have curly hair while another has straight hair and one is blond and the other has brown hair. The dominant and recessive for each gene might be the same (homozygous) or they might be different (heterozygous). The dominant is the one we outwardly display and the recessive is the one we carry but isn't usually obvious or visible. Joan In a message dated 5/17/2012 1:00:35 A.M. Eastern Daylight Time, SODERSTRUM@aol.com writes: I have found the current discussion very interesting. There is one question which I would like clarified. In an autosomal test, such as the Family Finder from FTDNA, would the results be the same for tests from a brother and sister? Or would separate tests of each provide additional information? Possibly enough additional information to make the cost worthwhile? Another question which just occurred to me. Are the tests from 23 and Me and FTDNA different? Disregarding the cost, would tests from both companies be worthwhile or provide additional information? Bill ===== If you would prefer digest mode to mail mode, drop a note to roots-admin@rootsweb.com and ask for the digest... ------------------------------- To unsubscribe from the list, please send an email to ROOTS-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message