Monday, November 21, 2016

When did lines diverge?

With the current FamilyTreeDNA sale, the opportunity has been taken to kick start more of an investigation into when assorted lines diverged:

  • The Elliots and the Fairbairns who so closely match at yDNA STR testing (the 37/67/111 marker tests)
  • Lineage 1e from the others in haplogroup I1

    just for starters (yes I'm biased, my FAIRBAIRN branch is Lineage 1e).

    The test used here is BigY (currently $50 off on sale with further $$ off vouchers arriving weekly that may apply - I've heard some were for $100 off, the most I've found were $75).
    It is only available if the male concerned has already tested his yDNA, so isn't visible on the normal product page ( No re-scrape necessary if sufficient DNA remains in storage.

    This test runs hand in hand with SNP testing, and has an advantage over any SNP packs that FTDNA advertise in that for the latter you are playing catch up all the time as the tree advances, and have to keep re-testing to see if you match the newfound branch.
    For BigY you are helping science as well as your curiousity by leading that charge down the tree to the present day.  As new branches are found, your results are automatically updated, at least on who do further analysis of the results for a one-off fee.

    From prior individual SNP testing before BigY became available we know that the guinea pig tester for the FAIRBAIRNs, and by implication the group, had made it down to I-Z141 - which is equivalent to the I-Z140 one of the ELLIOT kits has tested for - - formed 4,300 years before present (present = 1950).
    We must be able to do better than that.
    One group down from the I-Z140 link above has a Time to Most Recent Common Ancestor of 50 years, yes that's 50 !

    As for all DNA testing, it cannot be done in isolation, it needs comparisons.
    Any takers from the ELLIOTs?
    From other groupings in the I1 lineages?
    We do need at least one other BigY test within the group to compare against to get full value from this.

    A new set of vouchers will be arriving soon, so if interested, check out the FAIRBAIRN project activity feed to see if any are available.

    As an example of what can happen, take a look at the Runciman project diary where we were trying to determine how long ago the four matching lines diverged. Question not yet answered, as they were still on the same branch estimated at around 550 ybp. We have hopes that another test will revise that further.