The Mozambique connection on Ancestry & MyHeritage

Mozambique is a somewhat overlooked country of origin for many Afro-descendants. To be sure the Trans-Atlantic Slave Trade with Southeast Africa was relatively smaller in scope than with either West or Central Africa. Still according to most recent estimates it involved almost half a million people (see this overview from the TAST database). Especially for Brazilians, Haitians and Cubans Mozambican lineage might be considerable in some cases. Plus also the Indian Ocean Slave trade is to be taken into account. Which most likely resulted in a dispersion of a similar number of Mozambicans (see this overview, taken from this paper). Especially into South Africa and the Indian Ocean Islands: such as Mauritius, Réunion and Madagascar. But also to the Middle East and into South Asia and beyond even. For more details:

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Map 1 (click to enlarge

Kaartje MH

I found 12 most likely African matches for a person who is himself 1/2 Mozambican and 1/2 Portuguese. Most of these matches actually were likewise of mixed background. With the majority being from South Africa (6x). But also tellingly one single close match from presumably Pemba, Mozambique! MyHeritage provides a very useful filtering tool which allowed me to zoom into shared East African DNA segments among this person’s DNA matches.

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Then again some people might also have Mozambican ancestry due to recent migrations. In the last couple of months I have been given access to DNA results which reveal an already confirmed Mozambique connection for two people of mixed background. With very fascinating outcomes! As well as useful implications for other people wanting to learn more about their own possibly Mozambican lineage.

The first person is living in the Netherlands (like me). Both of his parents were born in Mozambique. But going back two generations his father’s grandparents are all of Portuguese descent. While his mother’s family has been living in Mozambique for as long as can be traced back. But her family tree does contain at least two persons who were born in India and migrated to Mozambique as well. When it was still under Portuguese rule. All in all a very fascinating tale of migration across several continents! This person tested with MyHeritage and he has been featured in a Dutch documentary series called “Identity”. I was actually honoured to also contribute to this documentary which was shot in my birth place Rotterdam. The actual day of filming being the 5th of July which happens to be Cape Verde’s Day of Independence! Highly symbolic for me therefore 😉 1 See also:

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Figure 1 (click to enlarge)

STP

These are the recently updated AncestryDNA results of a person whose father is from Mozambique. His Southeast African DNA is clearly indicated by his main regions, incl. also “Eastern Bantu”! Another intriguing aspect is that this person actually also has a Cape Verdean connection by way of São Tomé & Principe. This is revealed by a very distinctive score of 6% “Senegal”. Probably also to be combined with the “Portugal” & “Spain” scores. Highlighting that regional admixture DOES matter!

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The other person is a DNA cousin of mine on Ancestry whose mother was born in São Tomé & Principe while his father is from Mozambique. I am related to him by way of a mutual Cape Verdean relative who migrated to São Tomé & Principe as a contract labourer during the first half of the 1900’s. São Tomé & Principe is a former Portuguese colony just like Cape Verde and Mozambique. But nowadays it is an independent island state located nearby Gabon in the Gulf of Guinea. Just like Angolans and Mozambicans many Cape Verdeans ended up settling in São Tomé & Principe during the Portuguese colonial time. Notoriously being employed under very harsh circumstances on the cocoa plantations of São Tomé & Principe. It therefore still has a sizeable community of Cape Verdean descendants. Their continued longing for their motherland has been made world famous by the song “Sodad” by Cesaria Evora (see this video clip).

This blog post will describe the DNA results of both persons. Seeking to demonstrate in particular how correlating regional admixture analysis with DNA matches can be rewarding and mutually reinforcing in many cases. In addition I will also discuss my experience with MyHeritage. As I have myself not tested with this company. And so this was the first time I had the chance to get acquainted with several of its features. Allowing me to also make some cross-comparisons with Ancestry.

  • Mozambican Connection on MyHeritage
  • Mozambican Connection on Ancestry
  • Comparing Ancestry with MyHeritage
    1. MyHeritage is distorting Central & Southeast African DNA
    2. Ancestry offers greater potential to find African matches
    3. MyHeritage provides more advanced filtering tools

 

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Ancestry’s 2019 Update: Back on Track Again?

Backontrack

Map showing all the regions available on Ancestry after its 2019 update. For Trans Atlantic Afro-descendants the most impactful changes seem to be that: “Nigeria” has been brought back to life again! But “Ghana” has been derailed. “Mali” is no longer overpowering “Senegal”, but it does include both Sierra Leone and Liberia now! See this link for a complete list of regions and genetic communities. Photo credits for top picture showing a train passing by a railway station in Ghana.

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Starting in October 2019 Ancestry has been rolling out a new update of their Ethnicity Estimates. As I have said before your DNA results are only as good as the next update. So it is best not to get too attached to them 😉 Given scientific advancements and a greater number of relevant reference samples one always hopes that a greater degree of accuracy may be obtained. But naturally no guarantees are given that this will indeed be the case. After all Ancestry’s update in 2018 arguably was a downgrade rather than providing any meaningful improvement! At least when it comes to the African breakdown. In regards to the European, Asian and Amerindian breakdown Ancestry seems to have made steady progress on most fronts. Continued also with this 2019 update.

From my experience the best indication of predictive accuracy is obtained by looking at how Africans themselves are being described when tested by Ancestry. Which is why I have performed a comprehensive survey among 136 African Ancestry testers from all over the continent to establish a more solid basis for judgement. In addition I have also looked into a representative array of 55 updated results from across the Afro-Diaspora. These findings will be described in greater detail further below. The outcomes are mostly positive for Africans themselves but more ambivalent for Afro-descendants. Probably because Ancestry’s algorithm is less adequate when describing the mixed and therefore more complex African lineage of the Afro-Diaspora. My overall verdict about this 2019 update: a step in the right direction but no substantial improvements for the most part. At least not when compared with the original African breakdown from the 2013-2018 version.

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Table 1 (click to enlarge)

Stats Afro

Based on the updated results for 121 African AncestryDNA testers from 30 countries, across the continent. Take notice that the predictive accuracy in most cases is quite solid. Although in a few cases it is still clearly in need of improvement. This goes especially for “Ghana” and “Eastern Bantu”. Follow this link for my spreadsheet containing all the individual results.

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Due to wild fluctuations in just two years many people might experience update fatigue. Some people will even be tempted to bash their DNA test results and admixture analysis in particular. But an overtly dismissive stance will be self-defeating and deprive you of informational value yet to be gained! As I have always argued that regional admixture DOES matter and Ancestry’s Ethnicity Estimates are of course NOT randomly determined.1 Ancestry’s predictions may not be 100% accurate but still in most cases they are reasonably well-aligned with the known backgrounds of my African survey participants. As can be verified from the overview above.

For those perplexed by all the changes do at least make an attempt to inform your self properly. Given how wrong Ancestry got it in 2018 (see this blog series) it is only natural that some grave flaws had to be rectified. Regrettably it seems in some aspects an over-correction did take place. Still depending on your background this update certainly also can be beneficial. Furthermore when considering your African breakdown in a macro-regional framework the changes have actually not been that drastic. And many things more or less remained consistent as I will discuss in section 3 of this blog post.

It has always been my belief that regional estimates require correct interpretation. And each updated version as well as each separate DNA testing company should therefore be judged on its own terms. Then again these admixture results can only take you that far. My advise is to also look into your African DNA matches, as well as historical plausibility and just plain genetic genealogy for greater combined insight. See also these links:

For those seeking deeper understanding of Ancestry’s 2019 update this blog post will attempt to take things further by having a closer look at:

  1. African breakdown for Africans before and after the 2019 update
  2. Ancestry’s Reference Panel & Algorithm
  3. African breakdown for Afro-descendants before and after the 2019 update
  4. Getting back on track again
  5. Screenshots of African updated results
  6. Poll on whether this update has been an improvement or not, please vote!

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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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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.).

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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.).

 

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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.

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Final summary: North & East 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. Continuing with my North & East African section. Which I first published on 20 November 2016 when I had only 58 North & East 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 has now more than doubled in sample size. Consisting of no less than 135 AncestryDNA results of  North & East African persons!  Follow the link below for detailed analysis & new screenshots:

Table 1 (click to enlarge)

Stats (n=135)

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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 which I still stand by.

  1. Careful follow-up research is required to substantiate any DNA results seemingly suggesting East African lineage.
  2. Careful follow-up research is required to substantiate any DNA results seemingly suggesting North African lineage.

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). Furthermore my findings may also serve as a benchmark for Ancestry’s upcoming update, which hopefully this time will lead to improvement! I find that currently 23andme is much better equipped to detect Northeast African & North African lineage. While also the distinction made for Southeastern African lineage on 23andme is particularly useful for Afro-Diasporans seeking to validate seemingly East African DNA test results.

From what I have seen (see this page) the new “Eastern Africa” category on Ancestry is much less predictive for actual East Africans. While interpretation for Afro-Diasporans is often tricky. When it comes to the new “Northern Africa” region on Ancestry the record is mixed. With interpretation again being tricky for Afro-descendants. More clarity may be obtained however when you critically assess your North and/or East African DNA matches, if you happen to have them. Taking into account shared segment size and the possibility of population matches and false positives, so that only genuine IBD matches are left over. Scroll down to sections 3 & 4 of this page for how I performed such a task for 50 Cape Verdeans and their 180 North African & 9 East African matches. 

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.

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Compil NEA

 

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.

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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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23andme’s new African breakdown put to the test

My first DNA test ever was with 23andme. Nine years ago already! In January 2010 I was thrilled but soon afterwards also quite underwhelmed to receive my very basic admixture results. The only distinction being made back then was between African, Asian and European DNA. Native American DNA did not even have a separate category yet 🙂 As I am of Cape Verdean descent I was actually most anxious to have my Upper Guinean lineage confirmed. Instead my African score just pointed towards the entire continent! One of my immediate reactions at that time therefore was:

“I hope that one day 23andme’s Ancestry Reports will be helpful in finding out where to locate my ancestry regionally and not just on a continental scale.”

After a (very) long wait it seems that this day has finally arrived! Last month 23andme rolled out an updated version (3.0) of Ancestry Composition to all their customers. Regardless of when they originally took the test. This update has actually been on release since September 2018 for 23andme’s most recent customers. But to its credit 23andme also made this update available to its earliest customers, like myself. Over the years I have been through more than one update on 23andme already. But this is the first time I can say that finally a meaningful African breakdown is being provided! For more details see:

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Figure 1 (click to enlarge)

23andmecompil

Updated 23andme results from across the African continent. A small but representative sample. Highlighting how 23andme’s new African regions appear to be quite predictive, for native Africans themselves. Unrealistic expectations about “100% accuracy” as well as counter-productive obsessing about regional labeling should be avoided. Instead take note of how the expected regions (circled in red by myself) reach levels of over 70% reaching into 98%! Taking a macro-regional perspective (combining overlapping regions from within West Africa versus Central/Southern Africa versus Northeast Africa) these results are usually in line as well. Also the additional ancestral locations appearing below the regional scores are on point!

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I have always believed that the best way to find out about the predictive accuracy of any particular DNA test or update is to look at the results of people who actually know their (recent) origins. In order to improve correct interpretation I have therefore started a survey among African DNA testers (n=173). Using their group averages as some sort of rudimentary benchmarks so to speak. Similar to the survey I conducted among African AncestryDNA testers in previous years (see this page). Of course also some basic knowledge about DNA testing (in particular 23andme’s reference populations and methodology) as well as historical context will remain essential to really get the most out of your admixture results!1

Main topics if you continue reading:

  1. Survey findings for 173 African 23andme testers from 31 countries (incl. 25 Cape Verdeans)
  2. Maps showing the geographical distribution of the new African regions on 23andme (based on my survey findings)
  3. Implications for Afro-Diasporans
  4. Examples to illustrate how regional admixture DOES matter!

Continue reading

DNA matches reported for 50 Cape Verdeans on AncestryDNA (part 1)

In this two-part blogseries I will analyze the DNA matches being reported by AncestryDNA for 50 of my Cape Verdean survey participants. A follow-up to my previous blog post about 100 Cape Verdean AncestryDNA results (see this link). Because I was kindly given access to their profiles I was able to use my scanning and filtering method of DNA matches in Excel (see this link). Aside from matches with mainland Africans I am also including matches with people of (presumably) fully Portuguese, Jewish, West Asian and South Asian descent.1 Below a statistical overview of my main findings. Going by group averages. For the individual results which do display greater variation follow this link:

Table 1 (click to enlarge)

DNA matches for 50 CV's

This table is based on group averages. Except for the columns mentioning the frequency of close and zero matches. So for example among my 50 survey participants only one single person received a close African match (>20cM). While two persons did not receive any African matches at all (excl. North Africa). But on average 5 African matches were reported of whom 4 were connected to the Upper Guinea area. (Senegal-Sierra Leone). The average admixture amounts are based on the recently updated Ethnicity Estimates on AncestryDNA. This update strongly reduced the trace regions. Especially for North African & West Asian DNA. For a previous version of this table see this link.

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Table 2 (click to enlarge)

African matches

The background column is mostly based on informed speculation (plausible surnames/regional admixture) but at times also confirmed by public family trees. The proportion of Upper Guinean related matches is 88% of all African matches (south of the Sahara). That proportion being equal to 227/257. Excluding North African matches from the total. The high number of Fula matches is quite striking. But this could very well reflect a greater popularity of DNA testing among Fula people when compared with people from for example Guiné Bissau who are greatly underrepresented in Ancestry’s customer database.

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This project was merely intended as an exploratory exercise. Of course my research findings have limitations in several regards. And therefore they should be interpreted carefully in order not to jump to premature or even misleading conclusions. Still I do believe they can reveal relevant tendencies in DNA matching for Cape Verdeans in general. These outcomes may also provide valuable insight into the various ancestral components found within Cape Verdean DNA. In particular when aiming for complementarity by also taking in to account admixture analysis, genealogy and relevant historical context.

Below an overview of the topics I will cover in this blog post:

  1. Considerations when dealing with DNA matches
  2. Upper Guinean matches: as expected African matches (south of Sahara) were overwhelmingly from Upper Guinea (Senegal-Sierra Leone): 88% of the total. In line with the 92% Upper Guinean admixture proportion  (“Senegal” + “Mali” / total African) I found for my survey group.
  3. North African matches: fairly consistent despite minimal shared DNA
  4. Other African matches: unexpected & uncommon. Higher odds of false positives but in some cases to be corroborated by additional clues, such as AncestryDNA’s ethnicity estimates?
  5. Methodology: how I filtered the African DNA matches as well as the decision rules I applied when determining a plausible background for each DNA match.

Part 2 of this blogseries will have the following topics:

  1. Portuguese matches: omnipresent and clearly most numerous as well as often hinting at relatively recent ancestral ties (1800’s-1900’s).
  2. Jewish matches: Sephardi matches more likely to be truly genealogical than Ashkenazi matches?
  3. West Asian matches: quite rare, possibly indicating that West Asian admixture among Cape Verdeans is generally indicative of actual North African or Sephardi lineage.
  4.  South Asian matches: also rare, but on a hit and miss basis still sometimes already seemingly validating trace amounts of South Asian admixture.
  5. Inter-island matching patterns: illustrated by the distribution of the shared DNA segments between myself and my 100 Cape Verdean survey participants.
  6. Methodology: how I filtered the non-African DNA matches as well as the decision rules I applied when determining a plausible background for each DNA match.

Dedicated to all my Cape Verdean primos and primas participating in this survey.And special dedication to my newly born nephew Max!

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