## Using "shared DNA" column in 23andme for triangulation?

5

On the 23andme site when you compare dna with a relative there is a column labeled "Shared DNA" and the description on their site says

Shared DNA means that you and your two genetic relatives share a portion of the same DNA segment. By clicking on the “Yes” links below you will be able to view where that overlap occurs in the DNA View of DNA Relatives tool.

several websites say that this is a true triangulation feature; for example https://dnagenealogy.tumblr.com/post/144966221253/relatives-in-common-quick-reaction

I have 2 questions:

1. If 23andme has a "yes" in this column is there a way to find out how much overlap? The viewer shows the segments and hovering above them shows the length of each segment but so far it looks like the only way to calculate how much overlap is to eyeball it.

2. Is there an efficient way to use this tool? I can see spending way too much time on this; first I need to select each relative I have, and then I need to go thru the dozens of pages that show up for each relative because of the 2 columns (one labeled "You" and one labeled with the relative I am comparing to) the column for me is in order of closeness but the one for the relative is not. So I might need to go down several pages before I discover that a 3rd cousin to me is a 2nd cousin to my relative I am comparing to. Each page click takes time to load...

It looks like I have a lot more relatives to work with on 23andme than I do on gedmatch which is why I'm trying to figure out how to do this.

4

Jim Bartlett recommends using the 23andMe's "Yes" feature to develop your Triangulation Groups.

Jim explains the whole procedure in his Triangulation at 23andMe article.

I'd highly recommend anyone working with segment matches and triangulation to read all of the articles at Jim Bartlett's segmentology.org blog.

And I wouldn't worry too much about the amount of overlap. As long as 23andMe is indicating that there is overlap and that it is triangulating, then the overlap is significant enough to be able to put it into a triangulation group.

0

As long as 23andMe is indicating that there is overlap and that it is triangulating, then the overlap is significant enough to be able to put it into a triangulation group.

https://you.23andme.com/tools/relatives/ajax/?offset=0&limit=2000