Continuing the series of posts covering the various genetic admixture analytic tools hosted by Gedmatch, this post covers the Dodecad tool.
The team behind Dodecad carried out an extensive K=3 Admixture analysis of around 130 different populations and about 2,000 individuals from Europe, Asia, and Africa. Using the allele frequency results of this analysis, the Dodecad team were able to create an analytical model that represents West Eurasians, Asians, and Sub-Saharan Africans.
Based on a relatively small genetic sampling, it’s worth understanding that some results will probably be skewed. I’d advise to interpret the proportional results as representative rather than as actual. While not a pan-African continental admixture analytic tool, I was pretty optimistic about the results it would provide.
Before you cast an eye over the results, it’s worth understanding two of the main classification terminology for the Dodecad tests:
- Palaeo-Africans: Sub-Saharan African tribes including the San, Mbuti and Biaka Pygmy tribes; and
- Neo-Africans: Sub-Saharan tribes including the Yoruba, Mandenka and Bantu-speaking tribes
Dodecad V3 Admixture Proportions
Africa9 Admixture Proportions
According to the explanatory notes, the number of SNPs for this analysis is small: there is probably noise in the minor components, but the major components of one’s ancestry should be well-defined. As such, this DNA analytical tool should be used by Africans and African-West Eurasian admixed individuals. It is not meant for people with additional admixture (e.g., South/East Asian or Native American).
Given my own exceedingly mixed genetic inheritance, I was pretty happy with the basic snapshot of African DNA distribution given above – at least within the African populations that this test covers.
World9 Admixture Proportions
This test was designed to measure Amerindian admixtures.
An important caveat for Americans who suspect that they may have an Amerindian ancestor: trace amounts of Amerindian in this analysis might be attributable to ‘noise’. This component is also found in Siberia, and may represent either backflow from the Americas or the common ancestry of Siberian and Amerindian populations. I suspect that this is the case with my results through what I’ve already known about my genetic links to various Siberian cultures..
Dodecad K7b Admixture Proportions
This test was designed to focus on the analysis of African contributed admixtures.
Dodecad K12b Admixture Proportions
This test was designed to focus on the analysis of Eurasian contributed admixtures.
* OK, so I had to look this one up. Gedrosia is the hellenized name of an area that corresponds to today’s Balochistan. It mainly includes southwestern Pakistan, southeastern Iran and a very small section of southwestern Afghanistan
Alongside the Eurogene K-36 Admixture Percentages test, I’m pretty impressed by the suite of Dodecad tests. It’s the closest pan-African DNA analytical tool that I’ve experimented with to-date on Gedmatch.
The more I read about these free admixture analysis tools, the more I begin to realize that the data used to compile them comes from publicly available sources. In other words, there is limited access to data to compile large data sets which would provide truly refined results. The developers deserve props and kudos for spending an inordinate amount of time in developing free analytical tools.
It’s worth bearing the above in mind. If you’re of mixed African descent, my advice is to approach these free analytic tools as basic, illustrative overviews; unless you plan to have a full DNA test done.
Overall, I continue to be amazed at the additional genetic insights are available via an Ancestry.com DNA test I uploaded to Gedmatch.