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    1. [WHITE-DNA] Analyzing Matches at FTDNA FAMILY FINDER
    2. Marleen Van Horne
    3. FAMILY FINDER is FTDNA's autosomal DNA test. This test looks at a yours 23 chromosomes and finds other people who share matching segment with you. atDNA is measured in Centimorgans cM.  This is not exactly a measure of length, but if you think of it as a a measure of length, such as a centmeter or an inch, the matches might be easier to understand.  FTDNA reports your match information in two columns:  Shared Centimorgans and Longest Block.  These two numbers are the basis of Family Finder match analysis. Every human being has approximately 7,200  cM of autosomal DNA that has been inherited from all your ancestors, since the beginning of the species.  atDNA is spread out over your 23 chromosomes.  Each chromosome has a different amount, starting with Ch 1, which is the longest and ending with Ch 23, the shortest.  Every one has only atDNA on Ch1-22.  The x chromosome, or Chromosome 23, has two strands of atDNA if you are a woman and 1 strand of x atDNA and 1 strand of yDNA if you are a man. Consequently women have fractionally more atDNA than men. You inherit half of your atDNA from your father, and half from your mother.  Your inherited paternal and maternal atDNA, usually do not intermingle, unless your family has a history of cousins marrying one another.  If your Family Finder page is correctly set up, FTDNA can identify inter-family marriages. So you now have 7,200 cM of atDNA , half, 3,600 cM from each parent. Each generation back in time you go, the amount of atDNA you inherited from each ancestor in that generation is decreased by 50 %. Generation 5 GGG- Grandparents 225 cM 3.125% from each ggg-grandparent Generation 4 GG-Grandparents 450 cM 6.25% from each gg-grandparent Generation 3 G-Grandpatents 900 cM 12.5% from each g-grandparent Generation 2 Grandparents 1,800 cM 25% from each grandparent Generation 1 Parents 3,600 cM 50% from each parent Generation 0 You  7,200 cM So, of your 7,200 cM of atDNA, only about 225 cM was inherited from a ggg-grandparent.  This applies to both men and women. However, when you are looking for an unknown paternal ancestor, and have no idea of what the paternal biological surname is, there is no way to single out the paternal line surname, unless you get a match with a large number of Shared Centimorgans, in generations 1-5. Having received your test results, look at the first person in your match list.  The matches are sorted from highest to lowest. If you have matches of over 100 Shared Centimorgans, work with those people first.  Look for names you know from your research, try to identify the common ancestor.  It helps if your match has posted a family tree, or at least a list of surnames If they have posted a tree, there will be a little blue tree under your match's name. OK, I will stop here.  The next step, the Chromosome Browser. Let me know when you are ready. Marleen Van Horne

    12/26/2018 02:21:17