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  • #31
    MDV:

    as for the random English thing, the first mtDNA was sequence more than 25 years ago, when nobody had any clue about all this mtdna eve and the like (the tree was found only much later, after lots of observations and data). It just so happened that the first lab to manage this scientific feat (and it was a big scientific feat back then) was in the UK, so reasonably enough they picked an English person (who knows, may one of the researchers who worked in the lab? who knows, I believe the identity remains a secret). Had the lab been in Japan, they would have picked a Japanese person. Also remember that ancestry is only a minor use of genetic data: really what they are for is to study medicine and diseases.

    As for Eve's companion, he may or may not have left a trail. All we know is that all men carry the Y chromosome of a unique man who lived may be 60K years ago. Note that what we are saying is that all men have his Y-chromosome. But people have many more chromosomes. We may have other chromosomes coming from other ancient males living at that time. Simply, we don't have their Y chromosome. Also, the reason why male lines disappear more frequently than female ones is that in most apes (chimps etc., and including humans) males are violent and tend to kill the other males- or at least prevent them from having kids. Women are killed less often. Rather, they are taken as wives. As a result, male lines tend to disappear, while female lines survive.

    cacio

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    • #32
      Unequal Male-Female Population Sizes

      As for Eve's companion, he may or may not have left a trail. All we know is that all men carry the Y chromosome of a unique man who lived may be 60K years ago. Note that what we are saying is that all men have his Y-chromosome. But people have many more chromosomes. We may have other chromosomes coming from other ancient males living at that time. Simply, we don't have their Y chromosome. Also, the reason why male lines disappear more frequently than female ones is that in most apes (chimps etc., and including humans) males are violent and tend to kill the other males- or at least prevent them from having kids. Women are killed less often. Rather, they are taken as wives. As a result, male lines tend to disappear, while female lines survive. cacio
      An excellent paper, "Genetic Evidence for Unequal Effective Population Sizes of Human Females and Males", Jason A. Wilder et al, 2004, explains the issue very well:
      http://lifescience.arizona.edu/image...ht/y-chrom.pdf

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      • #33
        Mutations is an old Indian word meaning: Bad Paper Trail.

        I think we are overusing the word mutations while discussing our DNA failures to match with supposed family members. Below is a few things that I have learned while studying DNA Mutations:
        Most mutations are harmful. A mutation may change the genes so that color cannot form in the skin, eyes and hair. If both parents have this mutation in their genes, and transmit it to their child, he will be an albino. Some scientists believe that certain types of cancer are caused by mutations.
        Human mutations occur rarely. Researchers estimate that a human gene may remain stable for 2,500,000 years.
        Some mutations are beneficial because they help a plant or animal adjust better to it’s environment. dc

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        • #34
          If most mutations were harmful, I would be a study in dysfunction. (Since I have so many of them.)

          Perhaps you are just suggesting that I use an alternate description for chromosomal alterations?

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          • #35
            By the way, albinism is not a disease and certainly not the worst condition one could inherit. It's just a lack of melanin.

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            • #36
              Perhaps you are just suggesting that I use an alternate description for chromosomal alterations?[/QUOTE]


              Could we use the word disarranged?

              I think Mutations is used way too much as as a tool
              for shoddy research.. I don't mean you.

              This is a rare condition (mutations) and is used way too often, I think..

              Thanks, dc

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              • #37
                Cacio, as my earlier post indicated, we agree on the range of dispersal of L0. I also agree on your point about the geography of slavery. However East Africa cannot be ruled out even though it is less likely. An autosomal test might be of help.
                MDV, we are all in luck. With few exceptions the mutations studied for genealogical purposes are not harmful (or beneficial).

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                • #38
                  Originally posted by darroll
                  I think Mutations is used way too much as as a tool
                  for shoddy research.. I don't mean you.

                  This is a rare condition (mutations) and is used way too often, I think.
                  A " mutation" is an alteration, or change, and nothing more.

                  A mutation in the coding region of any chromosome can alter the physical characteristics of the organism, and these changes can be viewed (from an evolutionary perspective) as good or bad.

                  A mutation in the non-coding region of a chromosome, which is what genetic genealogists study for the most part, are generally NOT reflected in the characteristics of the organism and should not be viewed as good or bad.

                  The change in the allele value for a DYS marker, for example, between one generation and the next is properly called a mutation.

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                  • #39
                    Originally posted by darroll
                    I think Mutations is used way too much as as a tool
                    for shoddy research.. I don't mean you.

                    This is a rare condition (mutations) and is used way too often, I think..

                    Thanks, dc
                    I'm getting the impression that what you're saying is that you shouldn't rely on mutations in genetic genealogy. Since that's the basis for comparison and making judgements in genetic genealogy, that would mean, by your logic, that genetic genealogy can't be relied on.

                    This is an old debate. It's true that mutations are very tricky to use in comparing two people, but the mutation rates are well-established. This gives you a certain probability to determine how long ago two people who match, say 37/37 or 35/37, shared an ancestor. It then is up to the two people to compare family trees to find the common ancestor or to do further paper trail research to find the common ancestor.

                    The method does work, as long as you combine genetic genealogy with paper trail-based genealogy. For proof of that, you can read some success stories in various threads on this message board.

                    Mike

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                    • #40
                      All,
                      I am no medic, but I was trying to get to the bottom of a 12 point DNA Y-Test.
                      I got a E-mail from a guy. He stated our DNA was a match. I said great. I asked why FTDNA did not contact me. I looked at our DNA comparison and we had a 11/12 match, FTDNA was right. Our surnames were similar. I told the guy that we were no match. He insisted that we were a match and I have to take the mutation into consideration. He hung his shingle on our tree about eight generations back. I don’t feel this guy is related.
                      Who is right? TKS, dc

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                      • #41
                        Originally posted by darroll
                        I got a E-mail from a guy. He stated our DNA was a match. I said great. I asked why FTDNA did not contact me. I looked at our DNA comparison and we had a 11/12 match, FTDNA was right. Our surnames were similar. I told the guy that we were no match. He insisted that we were a match and I have to take the mutation into consideration. He hung his shingle on our tree about eight generations back. I don’t feel this guy is related.
                        Who is right? TKS, dc
                        Neither of you is right.

                        An 11/12 match is inconclusive: it is neither evidence that you ARE related nor is it evidence that you are NOT related. It is, however, consistent with a genalogical relationship. If I were you, and he feels strongly that he's on to something, I'd suggest that he pay for an upgrade to 25 or 37 markers.

                        Perhaps your new "cousin" meant that you need to take the mutation RATE into account, which might be true. The one marker that doesn't match might be one that mutates relatively quickly. Even then, an 11/12 match is inconclusive no matter where the mutataion lies.
                        Last edited by vineviz; 1 August 2006, 02:30 PM.

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                        • #42
                          I'm a LO as well.

                          I'm an LO as well and a newbie also. Are LO's that unique in that there is not much information about this group? I'm African-American and read somewhere that it is rare to find African-Americans with this Haplogroup.
                          Last edited by Denise B; 19 October 2006, 03:34 AM. Reason: Mispelling

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                          • #43
                            Denise:

                            yes, in general much less is known about African haplogroups than European ones, simply because they've been sampled less. Another problem is that most haplogroups are spread all over Africa, and there's not much information yet on how to pinpoint the specific geographic origin in Africa of a given mtdna sequence.

                            According to Salas (The African diaspora: mitochondrial DNA and the transatlantic slave trade), L0 si relatively rare in African American, less than 5%; it is somewhat more common in Brazilian Africans (10% maybe). L0 is the most ancient haplogroup, and thus is pretty diverse. African American L0 belong almost uniquely to L0a. In Africa, L0a is common in the South East (Mozambique) around 25%, and in West Central Africa (may be 15%), as well as in Ethiopia. The fact that most slaves came from West Africa instead (where L0a is rare) explains the rarity of the haplogroup in the US (and the fact that is somewhat more common in Brazil, since the Portuguese had colonies in SE and Central Africa).

                            In addition to L0, there are also other, and completely different, L0 subhaplogroups, L0d and L0k. These are very common in South Africa (>50%). But because almost no slaves came from South Africa, L0d/k are basically absent in the US.

                            While difficult to read, the paper mentioned above has a neat pie chart of Africa and African-Americans mtdna, so you can google the article and look at the pie chart.

                            cacio

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                            • #44
                              Originally posted by vineviz
                              An 11/12 match is inconclusive: it is neither evidence that you ARE related nor is it evidence that you are NOT related. It is, however, consistent with a genalogical relationship. If I were you, and he feels strongly that he's on to something, I'd suggest that he pay for an upgrade to 25 or 37 markers.

                              Perhaps your new "cousin" meant that you need to take the mutation RATE into account, which might be true. The one marker that doesn't match might be one that mutates relatively quickly. Even then, an 11/12 match is inconclusive no matter where the mutataion lies.
                              Darroll: I agree with vineviz that you should upgrade your results. You need to remember that a very small percentage of people will even have a 11/12 match with their own father. A mutation is bound to happen at some point. If your surnames are similar and you end up with a 24/25 or 23/25 match, you may find a common ancestor sometime within the past 8-10 generations using conventional genealogical methods.

                              Good luck!

                              John

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