douglas YDNA tree

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Comment by Thomas howard edward douglas on January 13, 2018 at 18:41

Hi my name is thomas howard edward douglas and im trying to see how to read this chart. Im new to this and dont have alot to go on i would be extremely appreciated.

Comment by James David Douglas on January 11, 2018 at 16:33

Hi Robin

Great work on the Y chart,  do you have a higher rez version ?  

David Douglas

Kit # 442244

Comment by Robin Spencer on January 1, 2018 at 17:47

Thanks Jackie and a Happy New Year!  I've just run the analysis for Stewart:  drop me a note at spencerrw@alum.mit.edu and I'll reply with the diagrams (full size - I don't want to clog up the Douglas blog with others' material).

Also I must amend my little explanation below:  The example would prove that Bob cannot have an unbroken male line shared with Adam and Alan earlier than about 1000 AD -- but of course he could have a female ancestor anywhere along the way; her ancestry is invisible to Y-DNA analysis.

Comment by Jackie Stoddard on January 1, 2018 at 7:47

thats fantastic Robin Spencer , has anyone done this for Stewart as well?
I descend from the Earls of Angus , Glenbervie 

and Stuart / Stewart 
I have MANY Spencer DNA matches and am still trying to work it out , maybe its Douglas , I assume you dna tested on FTDNA ? did you do autosomal as well?
may I share this chart on my Stewart DNA group? , there numerous Douglas related on it 
I DNA match 58 with Spencer, 6 of which have Spencer surname (of my 2500 dna matches) on FTDNA 
many are Stewart linked too, Fitzrandolf and 6 Plantagenet with some Douglas

Comment by Robin Spencer on December 31, 2017 at 0:30

Thank you William -- you're an attentive moderator!  Someone asked a question about how to interpret this so here's a brief intro to genetic genealogy.  The sketch represents a small part of the above diagram.   Adam and Alan submit their Y-DNA and we see that they have a genetic distance of 3 (more or less by adding up the differences between the numbers for each marker in the table).  From traditional genealogy we also know that their most recent common ancestor was 5 generations ago. That provides the calibration from mutation distance to generations that we need.  

Now consider Bob, whose genetic distance from Adam or Alan is 18.  We apply our calibration to estimate that Bob's common ancestor to Adam or Alan must have been about 30 generations ago -- or about 900 years, around the Norman Conquest.  So if Adam and Alan have a famous ancestor who lived ca. 1700, then Bob cannot also be his descendant because his DNA is too different.

Comment by Robin Spencer on December 30, 2017 at 21:55

Thanks.  The reason that your Dad isn't there is that his kit number isn't in the list at https://www.familytreedna.com/public/douglas?iframe=yresults .  I wouldn't know why -- perhaps there's a sharing setting somewhere, or a hiccup in the DNA results page?  As time allows I will post the math and drawing code so that you can just select the Douglas URL and fiddle with the graphics yourself, but for now it's a manual process as I download the source for each data webpage.  If you see him at this site I'd be happy to add him.

Comment by Sherrie Douglas on December 30, 2017 at 21:25

The chart is very impressive.  I noticed not all the kit numbers are listed from the Family Tree DNA Test regarding the William Douglas connection.  My dads number is #732565.

Comment by William Douglas on December 30, 2017 at 18:53

A fascinating chart!

Thank you for sharing

William