Are African Americans really mostly “Nigerian”?

Last year 23andme’s research team published a major landmark study titled “Genetic Consequences of the Transatlantic Slave Trade in the Americas“. Arguably the largest DNA study to examine African ancestry in the Americas! Covering a wide span of the Afro-Diaspora, incl. also several thousands of African Americans. Highly interesting therefore. The research approach of this study consists of combining genetic data obtained from 23andme customers with Trans-Atlantic Slave Trade patterns. Which is practically the same approach I have been using ever since I started my AncestryDNA survey in 2013. This study by 23andme is even including Cape Verdean samples as a control group! Which is something I have done as well in all my research sofar.1 Since I have recently finished my survey findings based on 23andme results (2018/2019 version) it should be useful to compare notes.

23andme’s 2020 study

My own survey findings based on 23andme and AncestryDNA results

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Table 1 (click to enlarge)

This overview is showing the scaled African breakdown for the combined USA sample group (n=5785) featured in Micheletti et al. (2020). As well as for my own African American survey group (n=200). Despite smaller sample size actually very similar outcomes. Providing mutual corroboration. As can be seen “Nigerian” was clearly the most significant region. Going by group averages around 35%. Usually “Nigerian” is appearing as primary African category (162/200=81% in my survey). But even so “Nigerian” is still far from being predominant (>50%). Especially “Ghanaian, Liberian & Sierra Leonean” is also showing up as a substantial component. Furthermore regional scores indicative of Senegambian and Central African DNA are still considerable and nearly at 10%, on average. Making for an overall varied and rather balanced African breakdown. Do notice as well that around 20% of the African breakdown is falling in one of the “Broadly” categories!

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In this blogpost I will compare my own research findings (based on regional admixture) with 23andme’s study from 2020. In fact much of the data contained in 23andme’s study (based on the 2018 version of Ancestry Composition) is consistent with my own. As demonstrated above in Table 1. Which features the African breakdown for African Americans on 23andme (scaled to 100%).2 Despite smaller sample size on my part actually very similar outcomes. Providing mutual corroboration. The study’s main findings of lower Senegambian and higher Nigerian ancestry than expected for African Americans are in line with what I had already established in my 2015 survey. Based on AncestryDNA test results for 350 African Americans. As well as more recently in my 23andme survey. See also:

Within the remaining part of this blog post I will discuss the following:

  1. Why do so many African Americans have Nigerian ancestry?
    • Ancestral implications of “Nigerian” go beyond modern-day borders
    • Domestic Slave Trade from mostly Virginia spreading Bight of Biafra lineage
    • Lower Senegambian than expected because of less reproduction?
    • Substructure according to state origins
  2. African breakdown for other parts of the Afro-Diaspora 
    • Mostly in agreement with historical expectations
    • Overlap & differences with my own survey findings
    • Regional diversity and substructure
    • Confirmation of Upper Guinean Founding Effect?
  3. Discordances & limitations of 23andme’s study
    • Afro-descended samples taken from migrants underrepresent wider variation in countries of origin
    • Central African IBD disproportionately high when contrasted with regional admixture from Central Africa 
    • Sex-biased admixture: multiple & context-dependent historical narratives! 
  4. Exciting future prospects:  personalized 23andme results featuring African IBD specified according to ethnic groups Continue reading

Gullah Genetics

I have published another new page within the 23andme section of my blog. It features my survey findings based on 100 23andme results as well as 68 AncestryDNA results for African Americans with deep roots from South Carolina. Incl. several Gullah persons! Most of my findings are in agreement with previous published studies on African American genetics. In line with expectations Rice Coast related DNA seems to be more elevated indeed among South Carolinians.1 As indicated firstmost by a high frequency of primary “Ghanaian, Liberian & Sierra Leonean” scores on 23andme. As well as prominent “Mali” scores on Ancestry. But in fact also Central African lineage and strictly Senegambian2ancestry appear to be more pronounced in South Carolina than elsewhere in the USA. To be sure Nigerian (related) ancestry is very common in South Carolina too but intriguingly it seems to be relatively subdued among Gullah persons.

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Table 1 (click to enlarge)

This overview is exploring regional substructure between various parts of South Carolina. Obviously only preliminary due to minimal sample size. However already a very insightful constrast between coastal and inland areas is surfacing. The Lowcountry and Pee Dee clearly having relatively elevated group averages for “Senegambian & Guinean” and especially “Ghanaian, Liberian and Sierra Leonean”. While “Nigerian” scores are much more prominent in Upstate and Midlands. Intriguingly the substantial Central African level showing up in coastal areas is also maintained into Midlands.

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My analysis is also zooming into coastal areas and contrasting with inland areas within South Carolina. And this kind of granularity might be a first when compared with other research projects (along with the inclusion of Southeast Asian admixture statistics). Atleast as far as I know and also when dealing with regional admixture within Africa as well (otherwise see Parra et al. (2001) for a truly pioneering study). Such a comparison is particularly insightful when wanting to grasp the localized formation of the Gullah people in the Lowcountry and adjacent Pee Dee area! In order to avoid any assumptions being made on my part I will not use Gullah as a synonym for people from the Lowcountry and/or Pee Dee.3 Although of course this is the main area where they are located. Follow the link below for fully detailed analysis, references and screenshots (incl. also AncestryDNA results):

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Genetic Landscape of Gullah African Americans (Zimmerman et al., 2020)

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“Relative to southeastern non-Gullah African Americans, the Gullah exhibit higher mean African ancestry, lower European admixture, a similarly small Native American contribution” […]

“Despite a slightly higher relatedness to Sierra Leone, our data demonstrate that the Gullah are genetically related to many West African populations.” 

“This study confirms that subtle differences in African American population structure exist at finer regional levels. Such observations can help to […] guide the interpretation of genetic data used by African Americans seeking to explore ancestral identities.” (Zimmerman et al., 2020)

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In this blogpost I will compare my own research findings with a very interesting recent study on Gullah genetics. This paper, linked above, is currently still in preprint. But it is consistent with several of my own research outcomes. Especially in regards to the quotes above. Impressively the study is based on the autosomal DNA results of 883 unrelated Gullah African Americans! A much larger sample size than I was able to use therefore.

However due to differences in methodology regrettably its potential for breakthrough insights is not fully realized. Resulting in less regionally detailed outcomes than I was able to obtain with my surveys based on 23andme and Ancestry results. To their credit the authors of the study largely succeed in sketching an appropriate historical framework for properly contextualizing their research outcomes. But at times essential details are still lacking while some of the information given appears to be outdated or not well referenced. Within the remaining part of this current blog post I will discuss the following:

  1. Summary of my own survey findings based on 23andme and AncestryDNA results
  2. Review of Genetic Landscape of Gullah African Americans (Zimmerman et al.; 2020)
  3. African DNA matching patterns, beneficial for creating your own narrative about your personal African roots!
  4. Screenshots of 23andme & Ancestry results for African Americans from South Carolina

Continue reading

23andme’s African breakdown put to the test: Afro Diaspora edition!

In the last couple of years 23andme has implemented several updates. Often beneficial for Tracing African Roots! Starting with the introduction of a new African regional framework in 2018. Finally providing a meaningful breakdown of West & Central African ancestry! Soon afterwards I started a survey of 23andme results among Africans as well as African Americans and other Afro-descended nationalities.1 Similar to my previous Ancestry surveys my main research goal has always been to establish how much these results on an aggregated group level can already (despite limitations of sample size and other shortcomings) be correlated with whatever is known about the documented regional African roots for each nationality. As well as to improve correct interpretation of personal results.

Two years ago in February 2019 I published the first part of my examination of 23andme’s African breakdown. Which was based on my surveyfindings for 173 African 23andme testers from 31 countries (see this blog post). My 23andme survey has been ongoing till 23andme’s update in October 2019.2 Because of other projects I have not been able to process my entire data-set earlier. But in this blog post I will at last present my main 23andme survey findings based on 889 results from 28 different countries across the Afro-Diaspora! Actually I have already analyzed these results in greater detail (incl. screenshots of individual results) on these pages:

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Figure 1 (click to enlarge)

A small selection of 23andme results from across the Afro-Diaspora.  Most of the outcomes are roughly corresponding with documented African roots  for each of my survey groups. Unrealistic expectations about “100% accuracy” as well as counter-productive obsessing about regional labeling should be avoided. Instead focus on what ever informational value you can obtain despite imperfections. Take notice as well how the additional Recent Ancestor Locations are on point!

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To summarize: I do indeed believe that 23andme’s African breakdown has passed the test! Although obviously there are several shortcomings to take into account. 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 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. In the remaining part of this blog post I will discuss the following:

  1. African Breakdown
    • Main outcomes
      • Upper Guinean Founding Effect for Hispanic Americans
      • Virginia’s African roots most impactful on African American overall genepool?
      • Meaningful differentiation between Anglo-Caribbeans, Dutch Caribbeans and Garifuna
    • Frequency of primary African regions
    • Historical plausibility
  2. Substructure
    • African Americans, Brazilians, Cape Verdeans, Haitians, Hispanic Americans, West Indians
  3. Continental Breakdown
    • Southeast Asian admixture indicative of Madagascar connection
  4. Recent Ancestor Locations:
    • Pinpointing African lineage
    • Cross-Diaspora connections
  5. Screenshots 
    • Distinctive results across the Diaspora
    • Similar results across the Diaspora
    • Underrepresented parts of the Afro-Diaspora
    • Hispanic results reflecting Upper Guinean Founding Effect
    • Partially Cape Verdean results

Continue reading

200 African American 23andme results

I have just published a new page within the 23andme section of my blog. It features my survey findings for 200 African American 23andme results. Various themes/topics are discussed. Especially delving deeper into the African breakdown but also highlighting a remarkably widespread Madagascar Connection for my African American survey group! Follow the link below for fully detailed analysis, references and screenshots:

Of course my 23andme survey may have several limitations. The group averages I have calculated for my survey-(sub)groups are neither absolute or conclusive but rather to be seen as indicative. One main aspect to take to heart is that there will always be individual variation around the mean! Still the sample size of n=200 should be sufficiently robust to pick up on the main tendencies. I have made an extra effort to do justice to the entire African American spectrum across the country. Of course all done on a best-effort basis.

Continental breakdown

Table 1 (click to enlarge) 

Generally speaking most African Americans are clearly of predominant African descent, combined with minor other ancestral components. Almost all of this additional ancestry will usually be European in fact. Often to a minor but still substantial degree. Aside from much more diluted but still distinctive amounts of especially Native American and perhaps more surprisingly also Southeast Asian admixture! See this screenshot for an overview of my previous Ancestry survey findings (n=350). And also this one featuring the complete continental breakdown (n=200). The overall group averages being nearly identical!

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At the same time I have also focused on gathering atleast a minimum number of 20 survey participants each for Louisiana, South Carolina and Virginia. These are 3 key states when considering African American genetics & origins.

Table 2 (click to enlarge)

The state origins of my survey participants are not based on a 4 grandparents criterium per se. But often this was indeed confirmed by their profile details on 23andme. Either way insightful variation according to state origins. Take notice especially of the highest subgroup averages which have been highlighted in red. The African admixture ranges (min. – max.) were as follows: Louisiana (51%-94%); South Carolina (75%-99%) ; Virginia (56%-94%). Compare also with my previous survey findings on Ancestry.

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Chart 1 (click to enlarge)

This chart is showing the full extent of African ancestry among my African American survey participants. The most frequent African admixture interval is 80-90%.  Which is the same as it was during my  previous Ancestry survey (n=350, see this chart).

Continue reading

Update of 23andme’s African breakdown

After a long delay of any meaningful improvements 23andme has actually implemented several updates in the last two years. Often beneficial for Tracing African Roots! Starting with the introduction of a new African regional framework in 2018. In 2019 new reference samples were added for especially North Africa. While also the potentially very useful Recent Ancestor Locations feature has been greatly expanded. In this year 23andme has decided to upgrade their customized algorithm. Unlike the 2019 update this upgrade is poised to have a considerable impact on 23andme’s African breakdown. 

Not per se in a positive way though. As it seems that 23andme’s algorithm tends to be “over-smoothing”. That is to say it will tend to homogenize people’s DNA in just a few categories.1 As always one needs to refrain from being overly dismissive in order to also capitalize on any positive aspects. From what I have seen sofar this update does seem to be an improvement for many Afro-descendants, at least on balance. Of course I would need to see more updated results for a more substantiated judgement. For more details read:

Figure 1 (click to enlarge)

General trends of changes after 23andme’s update. According to 23andme (see this link).  The decrease in “unassigned” and most of the “broadly” categories is certainly observable. And especially within the European breakdown this will often be an improvement for Hispanics and African Americans. From what I have seen sofar actually an increase of “Nigerian” is not always happening for African Americans, or only marginally so. Also “Broadly West African” does not seem to change that much. But in particular “Angolan & Congolese” might often show a considerable increase. Often it seems at the expense of “Broadly Sub-Saharan African”.

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Either way it seems that this upgrade is likely to be rolled out to everyone and not just so-called V-5 customers. That is to say regardless of when you tested 23andme is aiming to eventually update your results using their new algorithm. At the latest early next year, 2021. Initially there was some confusion on whether “old” customers of 23andme (genotyped on the v1-v4 chips) would also receive this update. However quite recently 23andme’s customer service made this clarifying statement on 23andme’s forum:

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In October of this year, we completed testing and validating the updated algorithm for the latest genotyping platform (v5) and decided to release this update to v5 customers while continuing to work on testing and validating the updated algorithm for previous genotyping platforms (v1 through v4). These processes are independent: the set of variants tested on the v5 genotyping chip is different from the set tested on prior chips. This means that updates for customers on current and previous chips require independent research, testing, and validation. While we cannot guarantee that the new algorithm will pass quality control checks when applied to earlier genotyping platforms, we hope to provide this update to pre-v5 customers by early next year“. (source, or see also this screenshot for complete statement)

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For the sake of correct interpretation of 23andme’s African breakdown I performed a comprehensive survey among African 23andme testers from all over the continent in 2019. This survey (based on 23andme’s 2018/2019 version) was ongoing up till now. At this point my African 23andme survey includes 314 people from 36 countries! By looking into their group averages you can get a pretty good idea on how well 23andme is able to describe the African origins of people who are already aware of their specific African lineage. Because I have been able to expand my survey I can now comment in greater detail about the predictive accuracy of 23andme’s African breakdown (2018/2019 version). Beyond what I had already established in 2019.2 In the remaining part of this blog post I will discuss the following:

  1. African surveyfindings (2018-2019 version)
    • “Nigerian” also partially describes Ewe lineage from Ghana 
    • “Angolan & Congolese” is not always fully covering Central African DNA 
    • “Sudanese” is also being reported for Sahellian West Africans, incl. Tuareg
  2. Screenshots before & after 2019 update (Africans & Afro-descendants)
  3. Screenshots before & after 2020 update (Africans & Afro-descendants)

Continue reading

100 Jamaican AncestryDNA Results (2013-2018)

On 9 October 2015 I published my first preliminary findings based on 19 Jamaican AncestryDNA results (see this link). Right now, four years later, I have managed to collect a sample group which is five times greater! Consisting of no less than 100 AncestryDNA results of Jamaican-born or fully Jamaican descended persons.1 Although still limited this data-set already provides a rather robust basis. Allowing for a finer detailed analysis of Jamaican genetics. In the first place with regards to the African regional roots of Jamaicans. But in addition I will also cover the Amerindian, Asian and European admixture scores being reported for Jamaicans on Ancestry. As well as variation in African admixture in general. With a special focus on substructure.

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JAMDNA

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These results were obtained during 2013-2018 but I had not fully processed all the data up till now. Although actually in 2018 I already blogged about this survey group (n=100) in my comparison of various parts of the Afro-Diaspora:

Please keep in mind that AncestryDNA’s ethnicity estimates have been updated several times now! In this blog post I am dealing exclusively with AncestryDNA version 2 which was current between September 2013 and September 2018. All matters being discussed are therefore not pertaining to recently updated results (2018/2019) (unless mentioned so specifically). In my opinion especially version 3 (Sept 2018 – Oct. 2019) has been a downgrade rather than providing any meaningful improvement when wanting to learn more about one’s African origins (see this blogseries). The update which is currently rolled out will be reviewed at a later time.

I will mainly revisit and expand on previous findings. Using new statistics and background information. Furthermore I will present my preliminary 23andme survey findings for 28 Jamaicans. This blog post is also intended to be a prelude for my current research into the African DNA matches being reported for Jamaicans. Which will be featured in a follow-up post to this one. Below an overview of all the topics I will cover:

  1. African regional breakdown in line with expectations?
  2. Variation & substructure in African admixture levels
  3. European breakdown reflecting mostly British ancestry
  4. Asian admixture: more or less widespread than imagined?
  5. Traces of Amerindian admixture is proof of enduring Taino legacy?
  6. Comparison with 23andme results being reported for Jamaicans
  7. Current update of AncestryDNA’s Ethnicity Estimates 
  8. Screenshots of individual results & Youtube videos

Follow these links for my complete survey data & research methodology:

Table 1 (click to enlarge)

Macro

This table features an additional breakdown of my own making into 3 greater macro-regions: “Upper Guinea”, “Lower Guinea” and “Central Africa” (also includes Southeast Africa). I find this distinction useful because it allows certain regional patterns to show up more clearly. In particular it seems apparent that the bulk of Jamaica’s African roots are from the area in between Ghana and Nigeria (=Lower Guinea).

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Table 2 (click to enlarge)

Cont. breakdown JAM

The continental breakdown is often considered to be the most reliable within admixture analysis. Aside from reviewing the group averages it is recommendable to look into other statistical measures as well. As many people tend to have misconceptions on how “typical” their personal results might be. Compare also with my 23andme surveyfindings (n=28), see this table.

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Continue reading

Fula, Wolof or Temne? Upper Guinean AncestryDNA results 2013-2018

This blog post will feature a summary of my Upper Guinean AncestryDNA survey findings. A fitting conclusion of my African AncestryDNA research as I am myself of Cape Verdean descent. And therefore this particular section was of paramount significance to understand my own African Roots! These results were obtained during 2013-2018 but I had not fully processed all the data up till now. Relatively few African customers of Ancestry are hailing from this particular area. Which is why it was difficult to gather a sufficient sample size. But eventually I did succeed. Also through the valuable help of several friends!1 Follow the link below for detailed analysis & screenshots:

Table 1 (click to enlarge)

Stats, SEN, n=34

“Senegal” is primary for most countries throughout the wider Upper Guinea area. Usually with “Mali” as secondary region. This goes even for the northern part of Sierra Leone. But this country shows greater variation. With “Ivory Coast/Ghana” also being a prominent component overall. An almost equal “Mali” group average (38-39%) was obtained for 6 samples from Mali when compared with 3 Gur/Senoufo speaking samples from Burkina Faso, Ivory Coast & Ghana.

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Table 2 (click to enlarge)

Stats Fula

A clearly detectable Upper Guinean component is mirrored among the Fula from across Upper Guinea and the Hausa-Fulani. Indicating their shared Upper Guinean origins by way of eastwards moving Fula migrations. However due to their partial Nigerian Hausa lineage the Hausa-Fulani results can still be quite easily distinguished through their primary “Nigeria” scores.

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My final survey group now consists of 122 AncestryDNA results from Senegal, Gambia, Guiné Bissau, Guinea, Sierra Leone, Mali and Mauritania. Although still limited this data-set already provides a rather robust basis. All the more given that my combined survey group (n=122) contains a number of people which is almost three times greater than Ancestry’s Upper Guinean Reference Panel at that time (n=44; 28 samples being used for “Senegal” + 16 samples for “Mali”).

And also crucially I have managed to gather plausible ethnic details for many of my survey participants. Enabling me to compile a separate Fula survey group (n=46) which is quite extra-ordinary as it includes Fula people from a wide range of countries (see Table 2). While usually in published studies only Fula samples from one particular area are being covered (often from the central/eastern Sahel and not from Upper Guinea).

To a lesser extent I also uncovered more specific ethnic backgrounds among my Sierra Leonean and Senegambian survey groups. Allowing for a finer detailed ethnic analysis of Upper Guinean genetics. Which is why I think these “old” results may still be useful and are not obsolete yet. Even when I did discontinue this survey after Ancestry’s update in September 2018. Because in my opinion Ancestry’s new version of their ethnicity estimates regrettably has been a downgrade in regards to their African breakdown, overall speaking (see also this blogseries).

Five main implications for Afro-Diasporans can be singled out. These are discussed in greater detail on the main page. In this blog post I will mostly elaborate on the question if it is possible to distinguish Upper Guinean DNA. Furthermore I will briefly touch upon 23andme’s new “Senegambian & Guinean” category and also how Ancestry might improve things in the near future. Especially in light of their upcoming update.

  1. “Senegal” + “Mali” combined is a solid indication of lineage across Upper Guinea (Senegambia, Guinea Bissau/Conakry, Sierra Leone, western Mali).
  2. “Mali” can also be predictive of DNA found in Burkina Faso, northern parts of Ivory Coast & Ghana.
  3. “Ivory Coast/Ghana” can also be predictive of Sierra Leonean DNA
  4. “Africa North” might also be inherited by way of Fula ancestors
  5. “South-Central Hunter-Gathers” can also be predictive of West African ancestors

In summary: Regional admixture DOES matter! Judge each case on its own merits. Combine insights from different fields to achieve complementarity!

Figure 1 (click to enlarge)

COMPILUG

The two first results illustrate how AncestryDNA’s 2013-2018 version was able to clearly distinguish between Fula & Wolof lineage (for Africans themselves!). The additional “Africa North” and “Middle East” scores making the difference. To a lesser degree also within Sierra Leone some ethnic differentiation (going by group averages) could be observed. Obviously there was greater individual variation though. And in no way was either “Senegal” or “Mali” an exclusive marker for any given ethnic group! For Afro-Diasporans follow-up research is therefore required (DNA matches, historical plausibility, genetic genealogy etc.).

Continue reading

Akan or Ewe? West African AncestryDNA results 2013-2018

Without wanting to rehash things this blog post and one more upcoming will provide a quick recap of my final AncestryDNA survey findings for continental Africans. These results were obtained during 2013-2018 but I had not fully processed all the data up till now. Arriving now at the first part of my West African section. Which contains results from Liberia, Ivory Coast, Burkina Faso, Ghana & Benin. One striking research outcome was the clear distinction between Akan & Ewe results.

I first published my preliminary West African survey findings on 24 February 2018 when I had only 41 AncestryDNA results available for my analysis (see this overview). As my survey has been ongoing I have managed to collect a sample group which has now doubled in size. Consisting of no less than 82 AncestryDNA results from Liberia, Ivory Coast, Burkina Faso, Ghana and Benin! Follow the link below for detailed analysis & new screenshots:

Table 1 (click to enlarge)

Stats (n=82)

Notice the striking difference in group averages for “Ivory Coast/Ghana” and “Benin/Togo” for my Akan and Ewe survey participants. Although actually there was also much underlying individual variation (see this more detailed overview).

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Aside from my Nigerian survey group (n=87) the sample size of my Ghanaian survey group (n=42) was the biggest within my entire African survey. Although still limited this already provides a rather robust basis. And also crucially I have managed to gather plausible ethnic details for almost all of my Ghanaian survey participants. Allowing for a finer detailed ethnic analysis of Ghanaian genetics. Which is why I think these “old” results may still be useful and are not obsolete yet. Even when I did discontinue this survey after Ancestry’s update in September 2018. Because in my opinion Ancestry’s new version of their ethnicity estimates regrettably has been a downgrade in regards to their African breakdown, overall speaking (see also this blogseries).

I originally singled out three main implications for Afro-Diasporans. All of which can be maintained and have been discussed already in previous blogs. In this blog post I will revisit the question if it is possible to distinguish Akan from Ewe lineage. Furthermore I will briefly touch upon 23andme’s new “Ghanaian, Liberian and Sierra Leonean” category and also how Ancestry might improve things in the near future. Especially in light of their upcoming update.

  1. “Benin/Togo” also describes DNA from Ghana (see this blog post as well)
  2. “Ivory Coast/Ghana” also describes Liberian DNA
  3. “South-Central Hunter-Gatherers” suggestive of remnant West African Pygmy DNA?
  4. Is it possible to determine the most likely ethnic source(s) of your Ghanaian lineage?

Figure 1 (click to enlarge)

Compil GH

The two first results are most illustrative of how AncestryDNA’s 2013-2018 version was able to  clearly distinguish between Akan & Ewe lineage (for Ghanaians themselves!). Obviously there was greater individual variation though. And in no way was either “Ivory Coast/Ghana” or “Benin/Togo” an exclusive marker for any given ethnic group! Ghanaians will usually know of course (even when going back several generations they might also be more multi-ethnic than they are aware of). However for Afro-Diasporans follow-up research is required (DNA matches, historical plausibility, genetic genealogy etc.).

 

Continue reading

Igbo, Yoruba or Hausa-Fulani? Nigerian AncestryDNA results 2013-2018

Without wanting to rehash things this blog post and following ones will provide a quick recap of my final AncestryDNA survey findings for continental Africans. These results were obtained during 2013-2018 but I had not fully processed all the data up till now. Moving on now to Nigeria, with a special focus on how to distinguish Igbo, Yoruba and Hausa-Fulani lineage.

I first published my preliminary Nigerian survey findings on 22 September 2016 when I had only 15 Nigerian AncestryDNA results available for my analysis (see this overview). As my survey has been ongoing I have managed to collect a sample group which is now five times greater. Consisting of no less than 87 AncestryDNA results of Nigerian persons! Follow the link below for detailed analysis & new screenshots:

Table 1 (click to enlarge)

naija comparison

For all three listed ethnic groups “Nigeria” is the primary regional component. However more differentiation is detectable when zooming into secondary regions. In particular “Senegal” for the Hausa-Fulani clearly stands out when compared with the rest. Less clear-cut distinction between Igbo & Yoruba. However when taking into account relative proportional shares for “Benin/Togo” and “Cameroon/Congo” it is still already detectable.

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I discontinued this survey after Ancestry’s update in September 2018. Because in my opinion Ancestry’s new version of their ethnicity estimates regrettably has been a downgrade in regards to their African breakdown. In particular Ancestry’s update in 2018 has been disastrous for obtaining reasonable Nigerian DNA results. Generally speaking former “Nigeria” scores have sharply decreased and were replaced by inflated “Benin/Togo” and “Cameroon, Congo, Southern Bantu” scores. Just as a reminder this blog post is NOT dealing with those updated and usually rather misleading results! Instead read this blogseries.

My Nigerian AncestryDNA survey is actually the most extensive and oldest part of my African survey (2013-2018). Such results initially being very difficult to come by. However currently my sample size (n=87) is rather robust. Higher even than Ancestry’s own Nigerian sample size (n=67) during this period! And also crucially I have managed to gather plausible ethnic details for almost all of my Nigerian survey participants. Allowing for a finer detailed ethnic analysis of Nigerian genetics. Which is why I think these “old” results may still be useful and are not obsolete yet. Even when I did already establish in 2016 that “Nigeria” does not not cover the full extent of one’s Nigerian lineage.

I originally singled out three main implications/propositions for Afro-Diasporans. The first two ones have been discussed already in previous blogs. However not so the last one which I will revisit in this blog post. Furthermore I will briefly touch upon 23andme’s new “Nigerian” category and also how Ancestry might improve things in the near future.

  1. “Benin/Togo” also describes DNA from Nigeria (see this blog post as well)
  2. “Cameroon/Congo” can also be partially indicative of southeastern Nigerian lineage (usually to a minor degree though, see this blog post)
  3. Is it possible to determine the most likely ethnic source(s) of your Nigerian lineage?

Figure 2 (click to enlarge)

Compil NG 3x

All three results show a predominant “Nigeria” amount. Indicative of a high degree of shared origins for Nigerians, regardless of ethnic background. Then again there is a major distinction between Hausa-Fulani and southern Nigerian results because of in particular the additional “Senegal” score and absence of “Benin/Togo” & “Cameroon/Congo”. Overlap between Yoruba and Igbo results is much greater but still going by proportional shares for in particular “Cameroon/Congo” still some minor differentiation can be detected.

Continue reading

Final summary: Central & Southern African AncestryDNA results 2013-2018

Without wanting to rehash things this blog post and following ones will provide a quick recap of my final AncestryDNA survey findings for continental Africans. These results were obtained during 2013-2018 but I had not fully processed all the data up till now. Starting with my Central & Southern African section. Which I first published on 17 February 2017 when I had only 32 Central & Southern African AncestryDNA results available for my analysis (see this overview). As my survey has been ongoing I have managed to collect a sample group which is now three times greater. Consisting of no less than 96 AncestryDNA results of Central & Southern African persons! Follow the link below for detailed analysis & new screenshots:

Table 1 (click to enlarge)

stats (n=92)

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I discontinued this survey after Ancestry’s update in September 2018. Because in my opinion Ancestry’s new version of their ethnicity estimates regrettably has been a downgrade in regards to their African breakdown, overall speaking (see also this blogseries). Which is why I think these “old” results may still be useful and are not obsolete yet. I originally singled out two main implications for Afro-Diasporans or rather propositions which I will briefly revisit in this blog post. Also in order to tie up some loose ends.

  1. Congolese & Angolan ancestry more likely than Cameroonian ancestry?
  2. Southwestern Bantu ancestry much more likely than Southeastern Bantu ancestry?

Then again my intention is not only to look backwards but also forwards! In particular I believe that this dataset may provide a helpful baseline to compare with 23andme’s newly updated African breakdown (see this overview). As well as functioning as a benchmark for Ancestry’s upcoming update, which hopefully this time will lead to improvement!

Over all I would say that my African survey findings are pretty much reinforcing the main message I have been trying to get across from day 1: the labeling of ancestral categories in DNA testing is often not be taken too literally. However this does not mean you cannot derive a great deal of informational value from your socalled ethnicity estimates! Proper interpretation is a precondition. And it has been my experience that being aware of the DNA results of native Africans certainly helps in this regard. Even more so when also taking into account your African DNA matches, relevant historical context, (advanced) genetic genealogy and other means of follow-up research.

***(click to enlarge)

compil CSA3

A selection of some of the new results I have added into my survey. Extending the country range. And finally now also able to showcase Angolan breakdowns. Take notice that one of them has “Cameroon/Congo” as primary region while the other shows so-called “Southeastern Bantu” in first place!

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