Thursday, 18 May 2017

Benefits of BigY and yFull

The Fairbairn surname DNA project has reaped the benefit of testing a group for BigY and having the results analysed at


A new branch, I-Y32666,  with an estimated TMRCA of 225 ybp, has been created under I-Y7277  on the I1 haplogroup tree.

Now all we have to do is convince a few more of the matching Fairbairn kits, or an Elliot or two, to similarly test, to see how far back from that the Fairbairns and their matching Elliots (a very small subset of that surname project) diverged, or were still together for that matter!

Wednesday, 3 May 2017

MyHeritage result compared to Ancestry/FTDNA/GedMatch

A "cousin" (3C2R) was selected by MyHeritage to be one of their initial DNA tested population.

His match has just come through (kit had to be re-sent), so I thought it a good opportunity to compare results across companies given he (SB) had tested at MyHeritage and Ancestry, as well as transferring his Ancestry test to FamilyTreeDNA and MyHeritage.
I've tested at Ancestry and FTDNA, and transferred the latter to MyHeritage.

We are both on GedMatch: T087062 (my Ancestry kit on GedMatch is set to Research only to avoid duplicating matches and cluttering result lists) and A533474.

The moral of the story appears to be:
Fish in as many ponds as you can afford, and make sure you upload to GedMatch to get a consistent view across companies as the data certainly varies, particularly in the total shared DNA.

The largest segment shows as a more consistent value across different companies than the total DNA shared, which is way too variable to be a reliable indicator from any one company.

The largest segment (excluding Ancestry which doesn't report such details - grrr!)  ranges from
51.3 (GedMatch phased to his father) to 56.3 (MyHeritage) where FTDNA comes in at 52 so all within cooeee.

The biggest differences come in on the total shared DNA ranging from 44 to 104 cMs!
MyHeritage wins at a massive 104.8cM, presumably because my transferred in kit has about 40cMs imputed from their database when compared to GedMatch's 60cMs total shared over 7cMs or 20cMs imputed compared with FTDNA's 89 total.
Ancestry only shows 44cMs total shared.

On GedMatch even reducing the match parameters to 1cM and 300 SNPs the total shared was still only 66cMs compared to FTDNA's 89 (and increased the segments shared to 4 with one under 5cMs now being shown - compared with Ancestry's 3 shared segments)

Intriguingly however, his initial kit transferred to MyHeritage from Ancestry (v2) shows a grand total of 6 matches - and does not include me, nor the other two cousins we share, who are on MyHeritage that do all show up in his actual MyHeritage test, one of whom does not show up in my transferred in kit but does on GedMatch and FTDNA (53 total/20 cMs largest).

Predicted relationship comparisons:
MyHeritage: 1C2R - 3C1R
Ancestry: 4th cousins - range 4-6th cousins
FTDNA: 2nd to 4th cousins
Actual: 3C2R

The details:

His match to myself (mine a transfer in from FamilyTreeDNA, his a direct test)

MyHeritage result:
Estimated relationships
1st cousin twice removed - 3rd cousin once removed
DNA Match quality
Shared DNA
1.5% (104.8 cM)
Shared segments
Largest segment
56.3 cM
(no changes after the apparent recalculations being done around 4 May 2017)
Ancestry result (both tested here, me v1 SB v2):
Predicted relationship: 4th Cousins
Possible range: 4th - 6th cousins (  )
 Confidence: High
 where the info button showed a total DNA shared of 44cMs over 3 segments

FamilyTreeDNA result (his a transfer from Ancestry v2):
2nd Cousin - 4th Cousin    89  52   X-Match

where  there are 2 segments over 5cMs, 4 segments counting all over 3cMs and 16 segments when counted over 1cMs, including the X.
The X match consisted of two segments, both less than 3cMs (and cannot be on the line we are known to share).

GedMatch result (both from Ancestry tests (me v1 SB v2), at defaults from the one to one comparison)

ChrStart LocationEnd LocationCentimorgans (cM)SNPs
Largest segment = 52.2 cM
Total of segments > 7 cM = 60.1 cM
2 matching segments
Estimated number of generations to MRCA = 3.9

403006 SNPs used for this comparison.

GedMatch with his match phased against his father's (at default settings):

ChrStart LocationEnd LocationCentimorgans (cM)SNPs
Largest segment = 51.3 cM
Total of segments > 7 cM = 59.2 cM
2 matching segments
Estimated number of generations to MRCA = 4.0

402849 SNPs used for this comparison.

Reducing the comparison to 300 SNPs and 1cM:

ChrStart LocationEnd LocationCentimorgans (cM)SNPs
Largest segment = 51.3 cM
Total of segments > 1 cM = 66.7 cM
4 matching segments

402849 SNPs used for this comparison.