Ancestry Composition is one of the main tools on 23&me to learn more about your African ancestry by way of regional admixture analysis.1 On this page I will mainly focus on a few key aspects:
- Reference Populations
- Comparison with Ancestry’s “Ethnicity Estimates“
“Your Ancestry Composition report shows the percentage of your DNA that comes from each of 45 different ancestry populations worldwide. We calculate your Ancestry Composition by comparing your genome to the genomes of over 14,000 people with known ancestry. When a segment of your DNA matches the DNA from one of the 45 populations with high probability, we assign that ancestry to that segment of your DNA. We calculate the ancestry for individual segments of your genome separately, and then we add them together to get your overall Ancestry Composition.“
For a greater understanding of your estimated admixture scores it is always advised to learn more about the methodology used by 23andme to produce their results. In particular 23andme’s Reference datasets and 23andme’s customized algorithm are crucial. To read more about how Ancestry Composition works follow these links:
One of the main things to keep in mind is that what is shown in Ancestry Composition is only as valid as the next update! Whenever new reference populations get added and/or the underlying algorithm gets tweaked or redesigned your results will change! After a long delay of any meaningful improvements 23andme has actually implemented several new updates in the period 2018-2020. See also:
- Ancestry Composition (2013-2018)
- New African & East Asian Details in 23andMe’s Latest Ancestry Composition Update (August 2018)
- 23andMe Adds 1000+ More Regions and 30+ New Reports for Our Most Refined View of Ancestry To-Date (January 2019)
- 23andMe’s Latest Ancestry Service Adds Diversity and New Features (October 2019)
- The 23andMe Ancestry Algorithm Gets an Upgrade (October 2020)
Figure 1 (click to enlarge)
Of course with each of these updates the expectation will be that 23andme’s analysis gets more refined and more accurate. However no guarantees of course 😉 Which is why throughout the years I have undertaken many surveys in order to find out to what degree DNA testing for Afro-descendants (both regional admixture and also DNA matches) may correspond with expectations based on historical plausibility (especially slave trade patterns). And in addition I have also looked into the DNA results of African DNA testers to see how well their results may already correlate with known genealogy/backgrounds.
Obviously there are still several shortcomings to take into account. But based on both my African and Afro-Diasporan surveyfindings I find it quite impressive though that 23andme is often able to describe a person’s African origins in a meaningful regional framework. Which will usually indeed quite closely correspond with either known genealogy or historical plausibility. The additional non-African scores and Recent Ancestral Locations actually reinforcing the robustness of 23andme’s predictions. See also:
- 23andme’s new African breakdown put to the test (2019)
- 23andme’s African breakdown put to the test: Afro Diaspora edition! (2021)
- Update of 23andme’s African breakdown (2020)
- Regional Origins of the Afro-Diaspora according to Documented Slave Trade Patterns (2020)
“The reference datasets are made up of individuals from publicly available datasets including the Human Genome Diversity Project , HapMap , and the 1000 Genomes project , as well as individuals from private 23andMe data collections and a large number of 23andMe customers who have consented to participate in research. In total, there are 11,742 research-consented customers and 2,651 non-customers in these population reference datasets.“
For more details go to:
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Comparing with Ancestry
Not meant to be exhaustive in any way! I may eloborate in the near future. First of all it is crucial to realize that even when similarly labeled, ancestral categories on different DNA tests will not be perfect equivalents or measuring the same thing. Basically this is due to differences in reference samples as well as in algorithm applied by each separate DNA test. Either way the labeling of regional admixture categories is never to be taken too literally. Instead of fussing about it or being overly dismissive understand that this labeling is merely intended as an approximate proxy. Which can still be helpful if you also take into account: neighbouring countries; macro-regions (see this map); the known migrations of ethnic groups; pre-colonial history etc., etc…2
A second thing to keep in mind is that several updates carried out in the last two years have made a great impact on the regional admixture estimates reported by both 23andme and Ancestry. Arguably 23andme has maintained a greater degree of consistency and has shown steady improvement with their updates. The updates on Ancestry show a much more mixed record…although to be fair Ancestry is showing some positive changes again with its latest update (see this link). When comparing the African regional framework of AncestryDNA (2013-2018 version!) with that of 23andme (2018/2019 version) the following aspects stand out to me:
3 West African regions on 23andme versus 5 West African regions on Ancestry
- 23andme does not have any regions in place comparable to either “Benin/Togo” or “Mali” on Ancestry. This inevitably results in some shifts within the African breakdown. In theory this allows for a finer West African resolution on Ancestry. But regrettably after a promising start in its 2013-2018 version this potential has not yet been been fully realized by Ancestry. The wild fluctuations caused by Ancestry’s updates in between 2018-2020 have undermined a greater coherence of especially its West African framework.
- 23andme applies a more conservative approach than Ancestry. Whereby African DNA which cannot be classified reliably (given their limited set-up) is put under either “Broadly West African”, ‘Broadly Congolese & Southern East African”, or “Broadly African”. Some people don’t like this but frankly I prefer for DNA testing companies to go by the motto: “don’t be more specific than your underlying data allows for“.
- “Senegambian & Guinean” is quite similar to “Senegal” on Ancestry but is also covering Guinea Conakry. It seems that 23andme has an edge when it comes to predictive accuracy. Especially given that the current version of “Senegal” on Ancestry is not always reported consistently among Afro-descendants. See also this blogpost.
- “Ghanaian, Liberian & Sierra Leonean” is quite similar to “Ivory Coast/Ghana”. But with a clear shift to Sierra Leone and decreased coverage of Ghanaian DNA (especially for Ewe!). Still pretty accurate for native West Africans from these countries. Given the dramatic loss in predictive accuracy of “Ivory Coast & Ghana” on Ancestry since its 2018 update clearly 23andme has the upperhand here. See also this blogpost.
- “Nigerian” has nearly the exact same labeling as “Nigeria” on Ancestry. However it is much more predictive, going by results for southern Nigerians. That is when comparing with Ancestry’s 2013-2018 version. However Ancestry has actually greatly improved its detection of Nigerian lineage in its 2019 & 2020 updates. The “Nigerian” category on 23andme is still also covering DNA found in neighbouring countries. All the way west into Ghana even! Which will be relevant for especially Afro-Diasporans. See also this blogpost.
Map 1 (click to enlarge)
Map 2 (click to enlarge)
Map 3 (click to enlarge)
3 Central & Southeast African regions on 23andme as well as Ancestry
- “Angolan & Congolese” is quite similar to “Cameroon/Congo” on Ancestry. However it is fortunately much more focused on describing genuine Central African lineage. With hardly any overlap with the Bight of Biafra as was the case for “Cameroon/Congo” (2013-2018 version!). See also this blog post.
- “Southern East African” is somewhat similar to “Southeastern Bantu” on Ancestry. But much better defined because 23andme also has 3 separate regions in place for Northeast Africa. Big improvement therefore when wanting to single out such lineage. See also this blog post.
- “African Hunter-Gatherer” is pretty much the same thing as “South-Central Hunter-Gatherers” on Ancestry (currently renamed into “Khoisan, Aka & Mbuti people”) . In both cases very minimal for almost all people and hardly relevant as these scores are often to be traced back thousands of years rather than within a genealogically meaningful timeframe. South African Coloureds being a notable exception.
- Actually 23andme also has 3 additional categories for Northeast Africa as well as 1 for North Africa. Which currently do all have their equivalents on Ancestry as well (since the 2018-2020 updates). Except for “Sudanese”. But all of these regions are usually practically absent for Atlantic Afro-descendants. From my observations it is quite rare to see any such scores above trace level (>1%). Could be merely “noise” in many cases or otherwise an indication of Sahelian derived ancestry. The exception being “North Africa” which is frequently reported with minor but still distinctive percentages (even >5%) for Latin Americans and Cape Verdeans in particular. In most cases to be correlated with their Iberian ancestry though. Although actually at times also again a Sahelian/Fula ancestral scenario might apply.
Map 4 (click to enlarge)
Map 5 (click to enlarge)
Just for illustration a few African 23andme testers who discuss their results on Youtube. I have always believed when it comes to regional admixture the proof of the pudding is when people who are “100%” from one particular ethnic background take the test. Or also people of recently mixed but still known background. See how well their ancestry is being predicted or described and that already tells you a lot what you can expect for yourself 😉
AFRICAN AMERICAN & CAPE VERDE (1/4)
AFRICAN AMERICAN & LIBERIAN
NIGERIA (Yoruba) & RUANDA (Tutsi)
ETHIOPIA & SUDAN
1) According to many pundits only continental admixture is to be taken seriously in DNA testing. Sub-continental, a.k.a. ethnicity estimates, a.k.a. regional admixture only being fit for entertainment purposes. I myself have never taken this stance. Preferring to judge each case on its own merits. Attempting to maximize informational value despite imperfections and avoiding source snobbery. Which is why I have conducted my AncestryDNA surveys among both Africans and Afro-descendants in the past. Since 2018 I have also started similar surveys based on 23andme results.
From these ongoing research efforts I have learnt that regional admixture DOES matter and is of course NOT randomly determined. Correct interpretation and knowing how to really “read the data” is a crucial requirement though to get the most out of your results. The ancestral predictions by 23andme may not be 100% accurate but still in most cases they are reasonably well-aligned with the known or historically plausible backgrounds of my African & Afro-Diasporan survey participants. It can therefore be very valuable in your journey to Trace African Roots! To be combined with any other ancestral clues you may have, especially DNA matches. See also:
- Afro-Diaspora AncestryDNA results: A Comparison (2016)
- Update: Afro-Diasporan AncestryDNA Survey (2018)
- 23andme’s new African breakdown put to the test (2019)
- Speadsheet with Afro-Diasporan 23andme results
2) Several valid objections can be made about the country name labeling being applied on both Ancestry and 23andme. But the truth is that the labeling of ancestral categories will always be tricky and a trade-off! Ancestral categories referring to ethnic groups might be just as deceptive or even more so! As many people will again tend to take them too literally. Underestimating not only the sheer number of ethnic groups existing in Africa (thousands!) but also the complexity of interplay between fluid ethnicity, overlapping genetics and shifting political borders. The same goes for precolonial African kingdoms which again were not static entities. But instead very often ended up being multi-ethnic after expansion and assimilation of neighbouring peoples.
I do agree that more appropriate labels than the present ones can be conceived of. Also knowledgeable scholars in African & Afro-Diasporan history should be involved to redo the regional descriptions so that people will more immediately be aware of the ancestral connections being implied. An intermediate solution might be ancestral regions which are referring to either non-political geography or meta-ethnic/linguistic groups. Such as Atlantic, Mande, Kru, Akan, Gbe etc. (see this page). But I fear that inherently there will always be some degree of blurriness involved and exact delineation might be impossible to achieve in many cases. Instead of generating false hope it might be a more honest approach to go by the motto of “don’t be more specific than your data supports”.
Understandably many people desire to have the most specific degree of resolution when searching for their African roots. They want to be able to pinpoint their exact ethnic origins and preferably also know the exact location of their ancestral village. In a way following in the footsteps of the still very influential ROOTS author Alex Haley. Unfortunately these are rather unrealistic expectations to have in regards to DNA testing (at least in regards to admixture analysis.). Not only given current scientific possibilities. But also because such expectations rest on widely spread misconceptions about ethnicity, genetics, genealogy as well as Afro-Diasporan history.
Too often people ignore how the melting pot concept is really nothing new but has always existed! Also in Africa where inter-ethnic mixing has usually been frequent! Throughout (pre) history and maybe even more so in the last 50 years or so. Generally speaking ethnicity is a fluid concept which is constantly being redefined across time and place.
Too often people fail to take into consideration how due to genetic recombination our DNA will never be a perfect reflection of our family tree but might actually also at times suggest very ancient migrations.
- Everyone Has Two Family Trees – A Genealogical Tree and a Genetic Tree (Genetic Genealogist, 2009)
Too often people underestimate the actual number of relocated African-born ancestors they might have (dozens or even hundreds!). As well as the inevitable ethnic blending which must have taken place across the generations.
Too often people are still not informing themselves properly about Africa itself and the documented origins of the Afro-Diaspora. Many specific details may have been lost forever but there is a wealth of solid and unbiased sources available which can help you see both the greater picture as well as zoom in more closely to your own relevant context. See also:
- Fictional Family Tree incl. African Born Ancestors (Tracing African Roots)
- Is it possible to pinpoint a plausible ethnic origin for one’s African bloodline?(Tracing African Roots)
- DNA studies for Africans and Afro-Diasporans (Tracing African Roots)
- Documented ethnic/regional origins of the Afro-Diaspora (Tracing African Roots)
- Maps (ethnolinguistic, slave trade, various parts of Africa) (Tracing African Roots)