Wednesday, 27 April 2016

New Project Member ... with clues to the Spearin origin?

Please welcome a new project member to Genetic Family 1 (GF1; the Limerick Spearin's). Member 458314 is not a Spearin, he's a Graham. But he is a fairly close match to the members of GF1. And he may hold clues to the origins of the Spearin's in GF1.

Evidence from STRs
Below is the summary of Mr Graham's Genetic Distance to other members of the Spearin Surname Project at the 67 marker level. He has a Genetic Distance (GD) of 5/67 with his closest match, 6/67 with 4 other members of GF1, and 7/67 with two other members. He also matches two people in the Ungrouped category but much more distantly (9/67 and 20/67).

TiP Report (at 67 markers) for new member 458314 showing his GD to his closest matches in the project
(click to enlarge)

Clicking on the TiP Report for his 7/67 matches reveals that the TMRCA (Time to Most recent Common Ancestor) is estimated to be about 12 generations ago (50% probability level) with a 90% range of 6-21 generations ago. That roughly equates with 360 years before present (90% range 180-630 ybp), which in turn gives a rough estimate of the birth year of the common ancestor of 1590 (90% range 1320-1770, assuming the average birth year of those tested is 1950).

So why does Mr Graham match the GF1 Spearin's?

There are several possible Scenarios based on the DNA alone:
  1. There may have been an NPE (non-paternity event, e.g. adoption, illegitimacy, etc) somewhere along the line and Mr Graham is actually a Spearin, and we all share a common Spearin ancestor born about 1590 (I say we because I too am a GF1 Spearin).
  2. We Spearin's in GF1 are actually all Graham's, and the NPE was on our line, not Mr Graham's.
  3. Mr Graham and the GF1 Spearin's are actually related prior to the common usage of surnames, which in the UK occurred around about 1200-1300. However, we see from his TMRCA estimate that there is a 95% probability that he is related to the GF1 Spearin's sometime after 1320, so this scenario seems unlikely.
  4. What we are looking at is in fact an example of Convergence. This is when the genetic profile of one person appears to be fairly close to that of another person but in fact there are hidden back mutations or parallel mutations within their profiles that make them related much further back than they seem.

So which of these scenarios is the most likely in Mr Graham's case?

Evidence from SNPs
Well, we might get some clues from the terminal SNP markers of his closest matches. Mr Graham's own terminal SNP is the upstream SNP M223 placing him firmly in Haplogroup I (along with the GF1 Spearin's).
  • At 67 markers, he has 19 matches whose terminal SNPs include L1198 (x1), PF5268 (x1), Y18109 (x2; both GF1), Y6060 (x1), and Z166 (x2; 1 from GF1).
  • At 37 markers, he has 11 matches including L1198 (x1) and Y18109 (x1; GF1)
  • At 25 markers, he has 44 matches including CTS6433 (x1), L1198 (x1), PF5268 (x1), Y18109 (x2; both GF1), and Z166 (x2; 1 from GF1).

All these terminal SNPs (except one) are on the same or adjacent branches of the human evolutionary tree to that on which the GF1 Spearin's sit. I've marked these branches with a red dot in the diagram below. The exception is SNP CTS6433 which is on the following branch:
  • I-M223 > CTS616 > CTS10057 > Z161 > CTS2392 > Z173 > CTS6433

So although the exception is still within the I-M223 haplogroup sub-clade (like the GF1 Spearin's), it is a completely different branch.

However, taking all the evidence into consideration, there seems to be little doubt that Mr. Graham will test positive for L1198 - the only question is which of the sub-branches does he sit on. Currently there appear to be 3 possibilities - Y6060, PF5268, and Y18109 (the GF1 Spearin's). To answer this question, there are several courses of action open to Mr Graham:
  • do the I-M223 SNP Pack ($119) - this will test for most of the relevant downstream SNPs (in pink below) but not all of them (in blue). Additional single SNP testing (e.g. for Y18109) might be indicated thereafter
  • do the Big Y test ($575, or wait for the sale when it is usually $475 or lower) and a YFULL reanalysis ($49) - this will assess most/all of the relevant SNPs and detect some new ones too

Placement on the Haplotree of the Terminal SNPs of Mr Graham's closest matches

If further SNP testing reveals that Mr Graham sits on one of the adjacent branches in the haplotree (e.g. Y6060), then the connection will be very far back in time (L1198 for example was formed 3000 years ago approximately - see diagram below), and if that is the case we are probably looking at is Scenario 4, Convergence.

However, if he sits on the same branch as the GF1 Spearin's (Y18109) then we can conclude that we are related within the past 2200 years (approximately) as this is when it is estimated that the SNP Y18109 was formed (see previous post). This is consistent with any of the first 3 scenarios above, but does not help us distinguish which scenario is the most likely.

Only by doing the Big Y test (and a YFULL reanalysis) would we get a better idea of which scenario is the most likely. If we compared his Big Y results to those of the GF1 Spearin's who have already done the Big Y test, we might find any of the following:
  • He sits on an adjacent branch, below L1198 or below Y17535 => the most likely scenario is Scenario 4: Convergence
  • He sits on branch Y18109, matches some of the 10 SNPs in the terminal SNP block, but does not match others. This splits up the Y18109 10-SNP block (as discussed in a previous post) and places him on a new adjacent branch with a branching point estimated to be either before the common usage of surnames (=> Scenario 3 is the most likely scenario i.e. he is related to the GF1 Spearin's before 1200-1300 AD) or after the common usage of surnames (=> Scenario 1 or 2 is most likely). Either way, the new branching point could be dated and would move everybody concerned further down the human evolutionary tree.
  • He sits on the Y18109 branch, matches all 10 SNPs in the terminal SNP block, but does not match any of the unique SNPs of those GF1 Spearin members already tested => Scenario 1 or 2 is most likely
  • As above, he sits on the Y18109 branch, matches all 10 SNPs in the terminal SNP block,  and in addition matches one of the existing Big Y-tested GF1 members on some of their unique SNPs => possibly Scenario 1 is the most likely and an NPE has occurred somewhere along Mr Graham's ancestral line. This would also create a new branching point which could be dated and would move (some of) us further downstream on the human evolutionary tree.

Branching points & Terminal SNP blocks below L1198

Genealogical evidence
So far, the discussion has merely focussed on the genetic evidence. But this is where we bring in the evidence from Mr. Graham's known genealogy. It is his grandson who manages his DNA results and here is what he says:
I submitted my Grandfather's YDNA to get tested as his father Edward Graham (+ Sister) took his Mother's maiden name "Graham" and he has no recorded Father on his birth record.

So once the results came in we had 9 good matches for Spearing, Speiran, Spearin, Speerin

Now the fun begins finding the link to a Spearin in New Zealand.

So clearly there is an NPE in the Graham line and it is at the level of Mr Graham's father (born in 1901 in New Zealand). The question is: does it go back to a Spearin or to some other surname?

One obvious course of action (as Mr Graham's grandson suggests) would be to search for a Spearin in New Zealand in 1901 who could have been Mr Graham's father's father. There are several potential candidates* in New Zealand around this time with the names Spearing and Sperring (more usually an English variant) but no one by the name of Spearin, Speiran, Speirin, or Spierin (more usually the Irish variant associated with the GF1 group). So, there is no clear signal currently that a GF1 Spearin was the father of Mr Graham's father.

Next Steps
One could try to track down some of the present day New Zealand Spearing's and encourage them to do a Y-DNA-37 test to see if there is a close match to Mr Graham. Or Mr Graham could do the Big Y test (and YFULL reanalysis) to see where he sits on the human evolutionary tree relative to the GF1 Spearin's.

The latter seems like the best course of action as it will give us the most information. It is likely to give us quite a bit of additional information about our relative positions on the haplotree but it won't answer all our questions - it may not identify any additional surname candidates for Mr Graham's father's father, and it may not give us any further clues to the ancestral origins of the GF1 Spearin's.

And as has been the case for many years, it will still be a waiting game to see if any closer matches to Mr Graham or the GF1 Spearin's emerge over time.

But one day, we will get there (in all likelihood). It is only a matter of time.

Maurice Gleeson
April 2016

* from the New Zealand Electoral Rolls 1853-1981 on Ancestry

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