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For any two SNP, I would like to find their branch point in the Y-tree.

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  • For any two SNP, I would like to find their branch point in the Y-tree.

    I would like the result to show the branch point SNP and its estimated age. Also, it would be useful to have the chain of each SNP to the branch point.

    Currently, it takes some time to read the Y-tree to find this information.

  • #2
    Finding the "Most Recent Common SNP" (MRCS?) sounds like a very reasonable logic problem that someone should be able to solve. The problem of the age of that SNP relative to the two chosen SNP's may be more problematic, because estimating the age of any SNP is inherently very iffy -- but it wouldn't be any worse than the estimates we already have.

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    • #3
      I recently found this site that might help show the Y Tree

      https://www.yfull.com/tree/

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      • #4
        Originally posted by ech124 View Post
        I recently found this site that might help show the Y Tree

        https://www.yfull.com/tree/
        I agree, yFull makes it easier to determine as each parent branch of Subclade defining snp is listed in the tabs at top

        Take two yDNA SNPs, for example L165 and Y132090
        Looking them both up on yFull, tabs show common SNP of L23

        Attached Files

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        • #5
          Age estimation will be affected by how FTDNA curates SNPs into shared haplogroup blocks and what they list as unshared in your sample. While it is hoped that they provide a method that is comparable to YFull or McDonald/Ytree other factors come into play. Known ancient samples provide carbon dated results which can "anchor" specific branches for time estimates. Historically FTDNA doesn't utilize data which hasn't been generated/processed on their systems. How they constrain the ages for specific haplogroup levels will be of interest. FTDNA's apparent use of single reads to position SNPs in blocks outside of documented genealogical relationships for a single result is not a good practice. Breaking apart MNPs into individual SNPs and counting those as individuals could skew more recent time estimates.

          Age estimates are statistical ranges. Subtracting the age of one level from another level may not be appropriate due to the number of results going into a specific estimate and the variance in the number of SNPs utilized. Age estimates for under tested branches suffer from the normal issue arising from the statistics of using a small number of results (1, 2, 3,...)

          Also note that some "fudging" of ages can occur between specific levels in order to maintain proper parent child relationships between the haplogroup levels.

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