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  • #46
    Originally posted by burto
    So is everyone in agreement now that even 23andme and DeCodeMe are inaccurate? This is the impression I am getting from various posts...WHY?
    And why can't AbDNA and these 2 tests pick up something from 200 years ago or more if it has been passed down randomly through the generations?
    I was in the mind set to do the 23andme test in a few months when they have their X testing set up and more samples but am I wasting my time?
    These tests should not be on the market if they cannot gives results that have some degree of validity. It makes me so angry.
    What is "accurate"? AbDNA2.5 test 175 SNP's and the genome scanners test thousands. Even AbDNA (on their website) allows that a more accurate test would involve more SNP's and cost more. While I don't know the intricacies of competing admixture algorithms, can't judge them, admixture computation has been around for awhile and 23andMe has Pritchard (originator of STRUCTURE) as a consultant. Hence 23andMe or DeCode "must" be somewhat more accurate than AbDNA. But they are only more accurate today, there could be an improvement tomorrow.

    The limitation on admixture analysis are unavoidable: there are very, very few "markers" that have been identified that have highest incidence in only a single"population"; admixture has been going on for a long time; mutations mutate. And percentage ancestry estimates are only estimates and can only be estimated based on the number of markers sequenced. How many markers is enough if an entire human genome has more than three billion basepairs?

    So, one buys one's ticket and takes one's chances.

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    • #47
      Originally posted by Zaru
      As disparaging as autosomal testing may be I am of the belief that it is more helpful than hurtful. The problem with Y and Mt is that while it does test the finite lines it does not account for the infinite lines, of which are both horizontal and vertical as opposed to only vertical.

      For example, my maternal grandfather was "black", there was no way for me to test for this using Mt or Y Dna, but through autosomal I was able to confirm that I am indeed 1/4 sub-saharan African. I also have the paper trail to support that.

      I agree with you that it is not practical for us to have ALL of our family's paper records, so this does indeed work against us when trying to understand the autosomal results.
      For me I feel that I would prefer to have Y and MT on each one of my direct lines but that may never happen. If people feel that autosomal works for them thats fine. People take the DNA tests they feel would benefit them. It's just me in general that I don't feel would help my research with what I need to prove in the lines I have researched. I have a few lines that do not match surname and no paper why. Autosomal will not give me the answer to this question. I need other matches of Y DNA to these people outside our direct line to understand what may be going on.

      Comment


      • #48
        Originally posted by burto
        So is everyone in agreement now that even 23andme and DeCodeMe are inaccurate? This is the impression I am getting from various posts...WHY?
        And why can't AbDNA and these 2 tests pick up something from 200 years ago or more if it has been passed down randomly through the generations?
        I was in the mind set to do the 23andme test in a few months when they have their X testing set up and more samples but am I wasting my time?
        These tests should not be on the market if they cannot gives results that have some degree of validity. It makes me so angry.
        Don't count me in this one. I have not taken any of these tests.Only MT, Y and X in my family lines have been tested. Im just more of an MT and Y DNA person for what I feel will benefit my research. If autosomal's helps others, that's fine.

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        • #49
          Originally posted by Zaru
          As disparaging as autosomal testing may be I am of the belief
          For example, my maternal grandfather was "black", there was no way for me to test for this using Mt or Y Dna, but through autosomal I was able to confirm that I am indeed 1/4 sub-saharan African. I also have the paper trail to support that.
          If you maternal grandfather was "black" he would have passed on his x-chromosome to your mother and your mother would pass on x-chromosomes to you, and as males only have one set x-chr you would have a phased set of x-chromosomes half (?) of them from your maternal grandfather.

          Comment


          • #50
            Originally posted by burto
            So is everyone in agreement now that even 23andme and DeCodeMe are inaccurate? This is the impression I am getting from various posts...WHY?
            And why can't AbDNA and these 2 tests pick up something from 200 years ago or more if it has been passed down randomly through the generations?
            I was in the mind set to do the 23andme test in a few months when they have their X testing set up and more samples but am I wasting my time?
            These tests should not be on the market if they cannot gives results that have some degree of validity. It makes me so angry.
            The problem is not the beadchips themself but the instruments to analyse them properly, especially making the right division of both autosomal and x-chr haploblocks from the recombination hotspots. Unfortunatly some massive computer power is needed to get them all fully phased and divided, even just getting 650k data into Structure for standard analysis model is a serious challenge on your standard desktop.

            Comment


            • #51
              23 and Me ETC.,

              Hello ' ; Tomcat ;have you been tested by 23&Me OR DeCODEMe? Thanks KAT.

              Comment


              • #52
                Originally posted by Noaide
                If you maternal grandfather was "black" he would have passed on his x-chromosome to your mother and your mother would pass on x-chromosomes to you, and as males only have one set x-chr you would have a phased set of x-chromosomes half (?) of them from your maternal grandfather.
                X chomosome would have been pased down from Grandfather to all daughters but you would need more than one daughter to test to figure out which X was passed down to the daughters from their father and which they got from their mother. When a mother passes down her X to her children they recombine. Meaning that each child would get a slightly diffrent X from their mother. Per Dr Khran there is only a 3% chance a Woman's X will not recombine when passed down to her children. I took the X test with my sister to prove we shared the same father since my father is desceased. We did not take this test to prove race admixture.

                Comment


                • #53
                  Originally posted by kat
                  Hello ' ; Tomcat ;have you been tested by 23&Me OR DeCODEMe? Thanks KAT.
                  Nope. See below.
                  Last edited by tomcat; 14 November 2008, 02:36 PM.

                  Comment


                  • #54
                    Originally posted by kat
                    Hello ' ; Tomcat ;have you been tested by 23&Me OR DeCODEMe? Thanks KAT.
                    Nope. Only Y (67+SNP's), Mt (FGS), FTDNA X and Autosomal, AbDNA2.5 and DNATribes (21marker).

                    Comment


                    • #55
                      Originally posted by Yaffa
                      For me I feel that I would prefer to have Y and MT on each one of my direct lines but that may never happen. If people feel that autosomal works for them thats fine. People take the DNA tests they feel would benefit them. It's just me in general that I don't feel would help my research with what I need to prove in the lines I have researched. I have a few lines that do not match surname and no paper why. Autosomal will not give me the answer to this question. I need other matches of Y DNA to these people outside our direct line to understand what may be going on.
                      I am in the same boat with my Y Dna as well as my Mt! My mother was adopted and it appears that there was a non paternal event in my father's line. So in short, my paper trails are false positive if you will. I am hopeful that someday someone somewhere will test their Y DNA and it will match mine perfectly. That is really the only way that I will prove my Y line.

                      Comment


                      • #56
                        Originally posted by burto
                        So is everyone in agreement now that even 23andme and DeCodeMe are inaccurate? This is the impression I am getting from various posts...WHY?
                        And why can't AbDNA and these 2 tests pick up something from 200 years ago or more if it has been passed down randomly through the generations?
                        I was in the mind set to do the 23andme test in a few months when they have their X testing set up and more samples but am I wasting my time?
                        These tests should not be on the market if they cannot gives results that have some degree of validity. It makes me so angry.
                        I think DNAPrint 2.5 is a good test but I wouldn't say it's 100% accurate. The 23andme, I think, underestimates minority ancestry. What made me think that was the results for Dr. Roy King. His majority ancestry was 51% European and 39% African. Although I know genotype doesn't always equal phenotype but these tests should get the majority ancestry right. I don't doubt that Dr. King has Euro ancestry but I don't think it would be more than his African ancestry. The link for Dr. King's 23andme results: http://video.aol.com/video-detail/23...ing/1000689379.
                        Last edited by Starr173; 14 November 2008, 03:47 PM. Reason: spelling error

                        Comment


                        • #57
                          Originally posted by Zaru
                          I am in the same boat with my Y Dna as well as my Mt! My mother was adopted and it appears that there was a non paternal event in my father's line. So in short, my paper trails are false positive if you will. I am hopeful that someday someone somewhere will test their Y DNA and it will match mine perfectly. That is really the only way that I will prove my Y line.
                          Im really in the same boat as you . I was adopted and my birth mother was also adopted. We have all that proven and DNA to match so now I am missing my mother's father and there is no test to find out who he was and grandma wont fess up. We have some info on him but not enogh to ever find out who he was. All the men on maternal grandmother's side the men don't match their surnames on Y DNA. I need Y matches on this guys to move forward. Our family is a big biological mess so I feel ya!

                          Comment


                          • #58
                            Originally posted by Yaffa
                            X chomosome would have been pased down from Grandfather to all daughters but you would need more than one daughter to test to figure out which X was passed down to the daughters from their father and which they got from their mother. When a mother passes down her X to her children they recombine. Meaning that each child would get a slightly diffrent X from their mother. Per Dr Khran there is only a 3% chance a Woman's X will not recombine when passed down to her children. I took the X test with my sister to prove we shared the same father since my father is desceased. We did not take this test to prove race admixture.
                            If you had half "black" x-chr it would show of as a becon in your dna.

                            Comment


                            • #59
                              Originally posted by Noaide
                              If you had half "black" x-chr it would show of as a becon in your dna.
                              From what I was told Dr Khran's sibling X test can not tell race. And if your are speaking of 23andMe can prove African, Zaru apparently already knows there is African in the family. Im not understaning where this is going.

                              Comment


                              • #60
                                Originally posted by Yaffa
                                Im really in the same boat as you . I was adopted and my birth mother was also adopted. We have all that proven and DNA to match so now I am missing my mother's father and there is no test to find out who he was and grandma wont fess up. We have some info on him but not enogh to ever find out who he was. All the men on maternal grandmother's side the men don't match their surnames on Y DNA. I need Y matches on this guys to move forward. Our family is a big biological mess so I feel ya!
                                Do you have his name from your mother's birth record? Do you have your mother's birth record?Is there one? I was fortunate that their was one on record in the Town Hall in this itty bitty town in New England.

                                Perhaps some old timers in the local diner knows some of your family's history? That's how I confirmed what a stranger had initially told me. I walked into a diner and asked some really old men who were drinking coffee if they new the "X" family- the responded by saying, "oh yeah them COLORED folk who owned a farm down the road there." I ran right into the Town Hall and began pulling records for these people ("Colored, Black, Negro, and African" are what the records all stated) going back to almost 1800!

                                I went 35 years of life visiting this small town, my father's family and my mother's foster family, and no one mentioned anything about it. Even after I enquired about it afterward. Stoicism has no place in genealogy, that's for sure.

                                Good luck to you as well!

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