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.
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:
For those who are not aware: ROOTSTECH Connect is the world’s largest family-history technology conference. And this year it will be a completely FREE and VIRTUAL experience! Hundreds of amazing sessions will be available online during and also after RootsTech Connect has ended on February 27th! Many of those sessions will offer precious insight for Africans and Afro-descendants in their quest to Trace African Roots! All it takes to attend is a free online registration. Right now more than 315,000 participants from more than 200 countries and territories worldwide have already registered! For more details:
I am very honoured, grateful and excited to also be part of this tremendous event! Because I will be giving an presentation as well! I will be demonstrating my scanning and filtering method to zoom into African matches or any other type of lineage you are interested in researching. I originally devised this technique in 2017. And I have been using it ever since to conduct my ongoing African DNA matches surveys. After registering for ROOTSTECH you should be able to find my class listed in the various search menus. But you can also just directly see it by following the link provided above.
If you are having trouble finding your African DNA cousins this can hopefully offer you a great opportunity to systematically look for your African DNA matches!During the event there will be an occasion to ask any questions by way of a chatroom. But of course you can also always reach me here on my blog if anything needs clarification or just to leave a comment. See also:
In the remaining part of this blog post I will show a few slides for a sneak preview 😉 Furthermore I will also provide all materials/links mentioned during my presentation. For those intending to watch my presentation: Thank you for your attention! I will be rooting for you that the ethnic filtering method I have discussed will be beneficial for you as well!
On 14 July Ancestry announced that they will pull the plug on the smaller matches they have been reporting for years now. In particular distant matches which show a shared DNA amount within the range of 6cM – 8cM. For many people this may effectively wipe out more than half of their total matches. Furthermore for Afro-descendants this could mean the loss of many invaluable African matches! Overall I would estimate that on average in between 50-75% of all African matches might be erased by Ancestry’s update.1 In one big drastic operation… and with just a few weeks notice…
An alarming situation for anyone who is reliant on their DNA matches (incl. smaller ones) for their research. Fortunately there are some strategies to preserve your smaller matches. Especially by contacting them, grouping them, starring them or adding notes. For more details see this overview of various helpful blog articles:
In this blog post I will focus on the importance of smaller African matches. Something which has been revealed to me in my ongoing research on African DNA matches since 2017.2 Even when indeed many of them will be false matches. Precious informational value may still often be obtained. But it seems that this importance has not really sunk in yet with Ancestry or perhaps they have other priorities… Either way Ancestry’s announcement has been brutally abrupt and will catch many people by surprise.
I hold no illusions about a complete reconsideration of this update (I love to be proven wrong though!). However I do hope the main arguments listed below may at the very least persuade Ancestry to delay their intended update. Even more so I wish that they wisen up and instead will implement tailor-made solutions which take into full account the diversity of their customer needs! If you agree please forward this blog post to Ancestry! For example in this suggestion box. See also the last part of this blogpost.
Added value of small African matches
Dangers of small African matches
Appeal for true committment
Why even small African matches matter!
Afro-descendants face exceptional challenges when Tracing African Roots. Given the lack of a paper trail for the most part they have to go by any clues given! Out of sheer necessity the net has to be cast wide. An openminded and creative research approach is required. Both including but also going beyondgenetic genealogy. All the while avoiding source snobbery in order to maximize any potential informational value.
Ancestry offers the biggest pond of African matches by far, when compared with other DNA testing companies. In great part because of its lower matching threshold which starts at 6 cM. This has been a precious resource for many which cannot be found elsewhere. It will be a tremendous loss when this pool of African matches will no longer be available or shrunk to a mere shadow of its former size!
Smaller matches may serve to reinforce more solid ancestral clues provided by related bigger matches (for example sharing the same meta-ethnic background). When combined with associated regional admixture and insights from other fields possibly leading to fruitful complementarity. See for example my survey of African DNA matches reported for 30 Jamaicans.
Small matches will indeed often be false matches or genealogically irrelevant but they may still be historically relevant (given correct interpretation). Leading to more insight of one’s African heritage within a greater timeframe. In particular when appearing with increased frequency. See for example my survey of African DNA matches reported for 50 Cape Verdeans.
In this blog post I will analyze the African DNA matches being reported by Ancestry for 30 of my Jamaican survey participants.1 A follow-up to my previous blog post about 100 Jamaican AncestryDNA results (see this link). Most important finding arguably being that Nigerian & Ghanaian predominance in regional admixture (2013-2018 version) for Jamaicans is also reflected in their DNA matches. Notwithstanding recent updates on Ancestry 😉 Furthermore there is no longer any excuse NOT to be looking for African DNA matches. I found on average almost 30 African DNA matches for each one of my survey participants!!! There are plenty of Africans who have tested with Ancestry by now. So you only need to search for them and then you will be rewarded with greater insight and closer connection to your African heritage! See also these links:
Because I was given access to their profiles on Ancestry I was able to use my scanning and filtering method of DNA matches in Excel. Aside from African matches I will also be including Jewish and South Asian matches in my discussion. Below a statistical overview of my main findings. Going by group averages. For the individual results which do display greater variation follow this link:
All of my 30 survey participants received African matches. Also I was able to find 5 close African matches (>20cM)! On average 29 African matches were reported for each person. Around 80% of all African matches are connected to either Nigeria (16/29) or Ghana (7/29). The African admixture averages are based on the old 2013-2018 version of AncestryDNA. As I believe that despite shortcomings this version still offers the best fit for Jamaica’s known regional roots within Africa (see this link). Calculation of average & maximum shared DNA is based on the outcomes per survey participant. In all other tables below it will be calculated based on all DNA matches taken together.
Table 2 (click to enlarge)
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 West African (Lower Guinea) related matches is 87% (755/861) of all African matches. The high number of especially Nigerian Igbo matches is quite striking. Undoubtedly due to very substantial ancestral connections. But possibly also a bit inflated within this overall overview. Reflecting a greater popularity of DNA testing among Nigerians as well as Ghanaians when compared with other Africans. Francophone & Lusophone migrants still tend to be greatly underrepresented in Ancestry’s customer database. In particular it seems from Central Africa as well as Benin & Togo.
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 African DNA matching patterns for Jamaicans in general. These outcomes may also provide valuable insight into the various ancestral components found within the Jamaican genepool. Contributing to answering major questions like: Do Jamaicans have more Nigerian or Ghanaian ancestry? In particular when aiming for complementarity by also taking into account admixture analysis, genealogy and relevant historical context.
Below an overview of the topics I will cover in this blog post:
Considerations when dealing with DNA matches
Combine DNA matches with admixture analysis for more insight
West African matches: as expected Nigerian and Ghanaian DNA matches were clearly most numerous. Only a subdued number of matches from Upper Guinea. This outcome is roughly in agreement with a predominant Lower Guineanmacro-regional share of around 70% I calculated for 100 Jamaicans, based on admixture (see this chart).
Central & Southeast African matches: quite low in number. In contrast with often substantial “Cameroon/Congo” scores being reported for Jamaicans. Interestingly Cameroon is relatively well represented.
Other African matches: unexpected & uncommon. Higher odds of false positives but in some cases to be corroborated by distinctive admixture?
Substructure:are there any group differences according to admixture level, “genetic community” or parish?
Jewish & South Asian matches: disproportionately numerous whenever backed up by associated admixture (even in trace amounts!)
Methodology: describing how I filtered the African & non-African DNA matches as well as the decision rules I applied when determining a plausible background for each DNA match.
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:
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.
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 😉 1See also:
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!
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
MyHeritage is distorting Central & Southeast African DNA
Ancestry offers greater potential to find African matches
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 betweenAkan & 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:
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).
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.
Is it possible to determine the most likely ethnic source(s) of your Ghanaian lineage?
Figure 1 (click to enlarge)
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.).
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:
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.
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.
“Cameroon/Congo” can also be partially indicative of southeastern Nigerian lineage (usually to a minor degree though, see this blog post)
Is it possible to determine the most likely ethnic source(s) of your Nigerian lineage?
Figure 2 (click to enlarge)
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.
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:
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.
Table 2 (click to enlarge)
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.
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:
Considerations when dealing with DNA matches
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.
North African matches: fairly consistent despite minimal shared DNA
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?
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:
Portuguese matches: omnipresent and clearly most numerous as well as often hinting at relatively recent ancestral ties (1800’s-1900’s).
Jewish matches: Sephardi matches more likely to be truly genealogical than Ashkenazi matches?
West Asian matches: quite rare, possibly indicating that West Asian admixture among Cape Verdeans is generally indicative of actual North African or Sephardi lineage.
South Asian matches: also rare, but on a hit and miss basis still sometimes already seemingly validating trace amounts of South Asian admixture.
Inter-island matching patterns: illustrated by the distribution of the shared DNA segments between myself and my 100 Cape Verdean survey participants.
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.2 And special dedication to my newly born nephew Max!
Wishing to share the vibranium 😉 I have created a new page featuring the DNA matches reported by 23andme for 75 Africans, all across the continent. These results were collected by me in 2015 when 23andme’s Countries of Ancestry (CoA) tool was still available.
My survey results might have limitations in several regards but I do believe these African CoA results can still reveal relevant tendencies in DNA matching. I intend to compare these preliminary matching patterns eventually with my more recent findings for Africans who tested on Ancestry. I provide detailed background info as well as screenshots of the individual results on this page:
This blog post features the AncestryDNA results of 8 persons from 7 different countries. In particular i will list the (most likely) African DNA matches i was able to find for each profile. Using the tutorial i blogged about in my previous blog post:
Naturally this overview is not meant to be representative per se because these persons are in the first place individualswith unique family trees. It is mainly to show the variation across the Afro-Diaspora. Nonetheless I strongly suspect that many patterns to be observed will still be valid as well for other people of the same nationality or ethnic (sub)group.
***(click to enlarge)
For this overview I specifically chose people with one single predominant African regional score on AncestryDNA. In order to see how Ancestry’s “Ethnicity Estimate” lines up with predicted African DNA matches. More detailed analysis will follow in this blog post. If you continue reading you will also come across a section featuring inspiring stories of people who were able to reconnect with their African kin through DNA testing.