West Africa

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NOTE 09/08/2019

This page was first published on 18 February 2015. Please keep in mind that 23andme’s Ancestry Composition has been updated several times now! On this page I am dealing exclusively with results being reported in the period 2013-2018. All matters being discussed on this page are therefore not pertaining to updated results (2018 up till now). For more details see:

• 23andme’s new African breakdown put to the test (Feb. 2019)
• 23andme results from West Africa (part 1, Senegal to Ivory Coast) (after 2018/2019 update)
• 23andme results from West Africa (part 2, Ghana to Nigeria) (after 2018/2019 update

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Knowing which African populations score the highest for each of the 23andme “Sub-Saharan African” (SSA) categories can be a good guideline for their predictive ability. Below screenshots are all taken from people who have kindly agreed to share their results with me. For which i am very grateful! They were either born in the African country highlighted or have both parents from that country. These are obviously first of all individual results and very limited in number because there’s only very few Africans yet who have tested with 23andme. I’m posting them for illustrative purposes, mainly to get a very rough idea what to expect. Undoubtedly with more African 23andme test results you might see different or additional patterns. Still i think in most cases these screenshots below would be representative to some degree for how other people from their nationality or ethnic group would score hypothetically speaking.  I will provide a brief overview of the main patterns i’m able to pick up on. Of course it merely shows my personal opinions & thoughts and is not meant to be conclusive in any way 😉

p.s. I’m only showing screenshots of the African breakdown. You’ll notice it will often not add up to 100%. In most cases this is because of a well known “bug” in the current version of Ancestry Composition causing people of 100% “Sub-Saharan African” (SSA) descent to show trace levels of non-SSA admixture or “unassigned” ancestry, this can generally be considered “noise”, i.e. reflecting an artefact of the DNA test. Hopefully it will be fixed with the next update. In some other cases though the individuals will have genuine additional non-SSA ancestry, which might however be “native” to Africa still if it’s labeled as “North African”, otherwise it might reflect historical geneflow from outside of Africa within the last 500 years or even earlier.

 

• Despite the name this socalled “West African” category is really measuring ancestry from “Niger-Congo” speaking populations, not only from West Africa, but also including Bantu speaking parts of Central, East and Southern Africa. Aside from any genuine shared ancient ancestry within this huge language group this is also the result of 23andme choosing to include Luhya (from Kenya) and Bantu samples for this category.

• Afro-descendants will therefore be shown as overwhelmingly or even almost exclusively “West African” even when in reality they might have more Central African or Southeast African origins instead. Only a future update by 23andme providing sub-regional resolution within West Africa and separating Central and Southeast African ancestry will resolve this highly unsatisfying and confusing issue.

• Also Bantu speaking people from Central/Southern African countries will generally score over 90% “West African”. For Bantu speaking East Africans it seems to be a more varied picture (their screenshots can be seen over here). Among the results of actual West Africans i’ve seen personally, the ones from Ghana and Nigeria are showing the highest, nearly 100% “West African” scores. This could however be a side effect caused by the inclusion of several 23andme customers from Ghana & Nigeria into the reference samples used for the category. Similar to the Somali and Ethiopian samples this might have resulted in “overfitting” or a “calculator effect“.

• Although seemingly designed to be a “fit-all” category the “West African” percentages can still be somewhat useful if you pay close attention to the relative differences with the other African (SSA + North Africa) categories, even if they are showing up only marginally. Some of the results from Upper Guinea i’ve seen and also 1 from possibly northern Nigeria are suggestive of these persons having ethnic backgrounds which are characterized by having partial ancestral connections with populations who originally weren’t “Niger-Congo” speakers. In absence of such non-“West-African” or rather non-“Niger-Congo” markers i suppose it’s reasonably safe to assume you can rule out any substantial ancestry hailing from Sahellian Africa.      

 

**Highest scores among West Africans**

 

Ghana 1

Ghana 2

Nigeria 1 (Igbo)

Nigeria 2 (Igbo)

Nigeria 3 (Yoruba)

 

Nigeria 4 (possibly Hausa/Northern)

Liberia

Guiné Conakry (Fula)

Guiné Bissau (Mandinga)

Gambia 1

Gambia 2

Gambia 3

Senegal 1

Senegal 2

 

**Highest scores among Afro-Diaspora**

• Even though all Afro-descended results i’ve seen show up as overwhelmingly “West African” for reasons already discussed, the very subtle variation in relative dominance of “West African” percentages as well as the appearance of non-“West African” percentages are most likely indicative of differentiated origins within Africa. A future update with more sub-regional resolution will undoubtedly show this in greater detail.

• I’ve really only seen sufficient results for African Americans and Cape Verdeans to make any assumptions but it’s striking that especially Jamaicans seem to score the highest “West African” scores relative to total SSA. See also this spreadsheet i made based on results that were shared on the 23andme forum. It might be in line with their documented African origins being mostly from the area in between Ghana and Nigeria, and less varied (proportionally speaking) than those for African Americans. The same goes for Barbados btw, perhaps confirmed by the screenshot below.

• For Cape Verdeans it’s intriguing how relatively varied their SSA breakdown is being shown (given the limitations of the current Ancestry Compostion). Even though they could arguably be the most narrowly West African descended Afro-Diasporans it seems that really this “West African” category on 23andme is more so geared to capturing ancestry from Lower Guinea than Upper Guinea.  The SSA breakdown for Cape Verdeans is not shown as exclusively “West African” but including “broadly Sub-Saharan African”, some detectable “Central & South African” at times (but not consistently) and especially “North African”.

• I haven’t devoted a separate subpage to the “North African” category because it’s known historically speaking that many Latin Americans could have inherited partial North African ancestry via the Canary islands or converted “Morisco’s” from Iberia. So in that sense it wouldn’t be clarifying their African ethnic origins resulting from the Trans Atlantic Slave Trade. This could also be the case for Cape Verde to some degree however in addition and perhaps with a higher probability “North Africa” might also suggest direct ancestral connections from Northwest Africa, incl. the Fula who can also show significant North African ancestry (see the previous screenshot of Guinea Conakry and this article).

 

Barbados     

Jamaica

USA

Cape Verde 1

Cape Verde 2

Cape Verde 3

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