I've mentioned this a time or two, buried in threads that were already running and were on some other specific topic. So far, there has been no response. I continue to think it would be of broader interest, if the interested parties actually saw it -- so I thought I'd write a post in which it's the stated topic.
DNA studies generally, and those of the Y chromosome more particularly, have come a very long way since the Carter project was begun, with the fairly limited goal of determining who was, and who wasn't, descended from a few specific, prosperous and well-documented 17th century residents of Virginia. That testing program had essentially met its goals at a time when a 37-marker STR test was considered adequate, and a 67-marker test was state of the art. It was found, pretty early on, that Capt. Thomas "of Barford" Carter and Robert "King" Carter did not share a paternal ancestor; and that seems to have been about all their descendants wanted to know. (I use these as the example because I descend from one of them, but the point I'm attempting to make is much broader.)
In recent years, or even months, the science has taken giant steps as new technology arrived in the testing labs; and among other trends, SNPs (single nucleotide polymorphisms) have begun to edge out STRs (short tandem repeats -- the things of which the allele counts are listed, in one's 37 or 67 marker results -- 13 23 14 11 11-15 12 12 12 13 14 29, and so on) as the most trustworthy means of drawing a deep family tree. One fact that has evaded the notice of a great many genealogists (who tend to be the volunteer administrators of these surname projects) is that SNPs can be discovered down to the small branches, or twigs, of the human Y-DNA haplotree. In the group with which I'm concerned, R1b-02, only two people have tested SNPs at all, and apparently none more recently than about the beginning of 2011. Since then, the group that includes these Carters -- formerly described as the "North/South Cluster" of P312 (on the basis of shared, off-modal values of DYS437=14, DYS448=18, and GATAH4=10) -- has been extensively tested, and is currently known to have the additional chain of SNPs, in descending order: DF27, Z274, Z294, Z196, Z209, Z220, Z210, Z295, and -- if one is not of Iberian ancestry -- CTS4065.
The Deep Clade test at FTDNA never tested for any of these, as they had not been discovered and described when that test was last revised. About half of them can now be ordered a la carte, as individual SNP tests (although there is no good reason to do so); and fairly soon it should be possible just to order the last one or two in the chain, for around $35 to $40 apiece. Having a positive test for Z295 proves the rest of the chain, so those upstream SNPs don't need to be tested.
Even at the level of Z295, a great expanse of European territory and history is included -- but it shows that the deep ancestry of your line is not Basque, or Italian, or Irish. The R1b people in those areas descend from branches of the haplotree that diverged from yours over 1,500 years ago. You may, however, have a lot of distant relatives in France, or the Netherlands, or Poland... and when I say distant, I mean with a common paternal ancestor perhaps around 750 AD. After that, your people were on the move; and some ended up (by way of England) in 17th century Virginia. They have continued to diverge, and there are American SNPs yet to be discovered. However, at the level of Z295 or below, any American Carter with that SNP probably shares a documented ancestor. It will take less than $50 to prove it, once the SNP test is available. (At the moment several of these are only tested on the Geno2 chip, sold through the National Geographic Society but processed at FTDNA's lab. It currently costs $159.00.) I believe the lowest SNP on Group R1b-02's haplotree that is for sale at the moment is Z220 for $39.00. But that testing landscape is changing almost daily.
If anybody in Group R1b-02 (who has tested at FTDNA) would care to join the relatively new DF27 haplogroup project, I know you'd be welcome there, in that I'm one of the administrators of the group. Here's the url: http://www.familytreedna.com/public/R1b-DF27/default.aspx You will perhaps be encouraged to test a SNP or two, from time to time. But you don't have to do it, if you don't want to. It's a voyage of discovery, we're all in it together, and many of us think it is fun.
And by the way, when I say Group R1b-02, I'd include a couple of guys who have tested enough STRs for it to be apparent that they belong in the group, even though their "genetic distance" may appear to indicate otherwise. One is 52334, who has had a common RecLOH event at DYS385 (one side of the marker copies the other -- 11 -- rather than copying its parent 15); but that's one mutation (of four "steps"), not four separate mutations. The other is 16724, who has more off-modals in the first 37 than most of his Group R1b-02 cousins -- but only one more in the next 30 (up to 67) -- and all but two of the total are on very fast mutating markers. It's not a good idea to be too rigid about FTDNA's rule-of-thumb guidelines, especially in cases in which some of the offending mutations are shared with other members of the group, who have slipped in under the arbitrary wire. The Carters have been multiplying on these shores long enough for some lines to accumulate quite a few of these tiny distinctions.
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