Sunday, September 10, 2017

GEDmatch Admixture (heritage) Dodecad, Triangulated Groups and Finding Bio Family

Using Dodecad with Triangulated Groups

My Admixture combination of choice is found under Admixture (heritage) Dodecad and Chromosome Painting Reduced Size.

Next, enter your kit number and pull-down to select World 9.

Your result will be something like this.

When you rotate the image you see this view. (I prefer visuals to help me better understand stuff like this.) (Chr 1-22)

I use Admixture (heritage) chose Dodecad in conjunction with the proportions tool. (Note: these are not percentages because the size of each chromosome differs.)

On GEDmatch when we look at the Chromosome Browser we are looking at this view. The browser starts with Chromosome 1 at the top and goes down to Chromosome 23. This view is based on chromosomes if they were the same size. The GEDmatch creators (they are geniuses) alert you by using different colors along with text stating the start and stop points.

When we look at Triangulated Graphic Tree we see this view of a chromosome browser at the far left of the full graphic with tree branches. (See post on this blog, "GEDmatch Triangulation Tree Graphic: What the Heck Am I Looking At?"

If you use the Chromosome Comparison on FTDNA (Family Tree DNA) Family Finder you will see a view something like this:

Consistency with visuals is important for me. (I am one of those people who need to turn a paper map the direction I am facing--- (I don't have a Smart Phone. I have too many other learning curves right now--Genomate Pro and Open Broadcast are challenges--please send the best resources to me via comments.)

Now, when I have a triangulation group, I like to run this to get an idea of who they might be through their start and end position on the chromosome chart. I hope it will help me further determine which line contains which ethnicity. When I discover a MRCA (most recent common ancestor) for a TG (triangulation group) and I see the same ethnic mix on another unidentified chromosome; I have a better idea of what line I am following. It may well be the same MRCA, or someone further back in the same line. 

This also helps adoptees if one side of the bio family has a specific ethnic mix and the other does not.

Full siblings compared to see the similarities on the different chromosomes:

Full sibling 1

Sibling 2

Full sibling females with overlay.

Now, look at half-sibling females.

Half-sib female 1

The differences have to be studied closely.

Half-sibling Female 2

Half-sibling females overlay Chromosomes 1-22

One must observe what remains as well as what is missing. Because the women share the same maternal line, the small proportions of Amerindian, African, and Australasian are canceled out as not in common which leaves me to consider that all of these (though small amounts can be noise) might be present on one or both of the paternal sides. On the other hand, by observing what is in common, and doing quick calculations using proportions between these half-sibling females, (while taking into account differences that are unique to each individual during recombination) it is possible the bio-mother adds more Southern and Caucasus Gedrosia DNA to the half-siblings than their respective biological fathers. 

We must remember, Admixtures for heritage are continuing to be refined as more tests are performed world-wide. The results are subject to change as more metadata is included. 

(Which reminds me, if you are concerned about DNA and privacy there is a fantastic new documentary entitled, The Good American. It is about the NSA Thin Tread prototype program that gathered metadata AND guarded personal privacy. Thin Thread was replaced with the Trailblazer Project which removed the protection to personal privacy and that should concern everyone.)   

Happy Finding!


  1. I just made an assignment on DNA with the help of australian writing service and honeslty i' am fascinated and keenly interesting in figuring out my own geneology. Anyhow, thanks for the post :)

  2. Leslie I am glad you liked it if you have any questions, don't hesitate to ask.