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Áed in Macáem Tóinlesc

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  • Áed in Macáem Tóinlesc

    In my project to prove out a more reliable estimate of SNP mutation rates, I've worked mostly with blocks where the MRCA was born within the last 300 years or so, since certainty about the MRCA's identity is key. But I also want to work with more remote TMRCA scenarios in order to improve precision.

    Performing a preliminary calculation based on information available in FTDNA's block tree for R-Z1513 returned some very interesting results. Supposedly their MRCA is the ancestor of Ireland's O'Neill dynasty of Tyrone, Áed in Macáem Tóinlesc, who is hypothesized to represent a clear break with the R-M222 signature of the alleged ancestral house, the kings of Aileach in Co. Donegal.

    "Most recently, DNA tests and research have proven the linkage between the MacShanes and the O'Neills of Tyrone. In a study begun in 2002, Patrick Guinness funded Trinity College, Dublin to conduct a DNA study on the O'Neil's of Ulster, to include the MacShane family. The results were published by Ed O'Neill and the late John McLaughlin that showed the McShanes were 100% match of a unique DNA sequence that is specific to the Chiefly line of the Tyrone O'Neills. It is estimated by Trinity College that the specific gene 'break' with the rest of the O'Neills of Ulster was either Aedh Macaomh Toinleasg O'Neill, King of Cenel Eoghain from 1176 to 1177, or his father, Muircheartach Muighe Line O'Neill.[citation needed]"

    A quick perusal of the O'Neill DNA project page seems to show R-Z1513 as a plurality of the published signatures, a lot of whom seem to have definite northern origins, so this claim may be plausible, although I can't find any direct link to a more detailed study substantiating them in credible detail.

    Running the numbers for the direct descendant clades BY3292, BY31270, BY57572, and FT32273 through my own proprietary dating algorithm returns an estimated birth year for the MRCA for R-Z1513 at about 1217 A.D., which is not too bad given the biographical details of Áed, who died in 1177 A.D. Assuming Áed was about 40 years old when he died, that puts him at the 64.8% confidence level of my calculation, much better than the 17.5% confidence level using the Adamov rates. In any event, my estimate of Áed's birth date is within the sample-size determined margin of error estimate for my algorithm, but well outside that of the calculation using the Adamov rates.

    But I don't suppose I can get too excited about this unless I can close at least some of the many unanswered questions surrounding this analysis. Can any of you help?

    1. How do they know for a fact that R-Z1513 is the signature of the historical O'Neill dynasty of the late Middle Ages? Have they tested any of the Portugese Wild Geese families or are they just guessing because they are a plurality of modern-day signatures in the project?

    2. What is their reasoning for specifically selecting Áed as the "break point" in the continuity of the genetic signatures? Basically, can I just get a full copy of the referenced report?

    3. What was the product specification in terms of base pairs of resolution for the original Big Y (i.e., pre-500 &-700)?

    4. Is there anyone involved with any of the several O'Neill DNA projects who can help me get more specific confirmation of the various testing resolutions? I feel like I'm making pretty good back-of-the-envelope estimates by looking at the distribution of reported average unshared variants within the anonymously aggregated FTDNA tree, but I would really like something more specific if possible.

    Thanks, and have a good one!

  • #2
    Never received any response to this information request. But in recent days I've developed a promising estimate of the proper mutation rate to use, a method to infer testing resolution indirectly from FTDNA's block tree, and an algorithm to estimate TMRCAs based on variant counts. I developed those by reference to four clades that appear to have well-attested Medieval founders, and just today decided to give it a test run by seeing how well it did against the information available on R-Z1513, supposedly founded by Áed in Macáem Tóinlesc.

    I am unaware of any reliable contemporary information specifically addressing his birth date, but as Áed is said to have succeeded to the kingship of Tír Eogain about 1167 A.D., I figure a birth year of 1136 A.D. is probably about right.

    The method I use is based on the observed distribution of variant counts rather than any single donor or subclade, so I necessarily had to exclude some reported data from my final calculation. I chose to accept all individual data points with calculated binomial confidence levels between 25% and 75%--that is, the center 50% of the confidence curve. This is not to say that somehow those clades that were not used for the final aging calculation are somehow "less certainly" descendants of R-Z1513 or of Áed, only that their variant counts deviate too much from the distribution mean for the purposes of performing this calculation.

    I'm very pleased with these results. The birth year I estimated for Áed is almost at the very center of the probability curve returned by the algorithm, 50%. I couldn't have asked for a better result.

    O'Neill data 29 Dec 2021 - pt III.png

    R-Z1513 Age Estimates 29 Dec 2021.png