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!
Last month Ancestry finally rolled out the updated version of its Ethnicity Estimates for all its customers. In this three-part blog post I have argued that Ancestry’s pioneering analysis of especially West African DNA has been downgraded rather than upgraded! In the first part I evaluated the accuracy of Ancestry’s new African breakdown by analyzing the before & after results of 130 African customers. I found that in most cases the informational value to be derived from their results is showing a decrease rather than any improvement. For more details see:
In part 2 I had a closer look at the newly added African samples within Ancestry’s Reference Panel as well as its new algorithm. And I found some structural flaws which most likely are responsible for the inflated “Cameroon, Congo & Southern Bantu”, “Benin/Togo” and “Mali” scores showing up for Afro-Diasporans. For more details see:
The update experience of the person who made this Youtube video is probably quite typical for other African Americans as well. Her main African region before the update was 21% “Nigeria” After the update only 2% remained. Understandably she assumes that Ancestry’s update has lead to greater accuracy. After all Ancestry’s samples have been increased from 3,000 to 16,000, right? However based on my evaluation in this blogseries I’d say it’s very likely that she’s still part of the Naija club!
The title of this blogseries was sort of meant to be tongue-in-cheek 😉 . However ultimately I do not see much benefit in taking a demoralizing stance. I do still believe that Ancestry offers opportunities for those wanting to learn more about their African ancestry. As always however it is essential to be fully informed about both strengths and weaknesses for each separate aspect of DNA testing. This particular update by Ancestry has arguably been a failed one for people of African descent. But this does not mean that improvement may still be forthcoming, if not on Ancestry than elsewhere! I am specifically referring to admixture analysis a.k.a. ethnicity estimates. As my previous AncestryDNA survey findings have demonstrated that potentially this tool can be very useful in unlocking the secrets of main African regional lineage for Afro-Diasporans.
In this final part of this blog series I will try to outline some promising developments, both on Ancestry and elsewhere, when wanting to Trace African Roots. I will also look into some common reactions & frequently asked questions about this disheartening update for Afro-Diasporans & Africans. Providing my own perspective. My main advice for achieving optimal insight in regards to your African breakdown can be summed up as follows: stick with your previous AncestryDNA results and combine with follow-up research (DNA matches, genealogy, relevant historical context, other types of DNA testing, etc.).
Earlier this month Ancestry finally rolled out the updated version of its Ethnicity Estimates for all its customers. Sadly the concerns I raised in July have become reality. Many people are now left confused by their revised African breakdown as reported by AncestryDNA.1 Understandably so given the often drastic and seemingly incoherent changes compared with the previous set-up. In this three-part blog post I will argue that Ancestry’s pioneering analysis of especially West African DNA has been downgraded rather than upgraded! In the first part I evaluated the accuracy of Ancestry’s new African breakdown by analyzing the before & after results of 130 African customers. I found that in most cases the informational value to be derived from their results is showing a decrease rather than any improvement. In the upcoming last part I will discuss FAQ’s about this update as well as look into promising new developments. See also:
Source: Ancestry’s White Paper 2018. Text in red added by myself. Compare also with this overview of Ancestry’s previous Reference Panel. The number of African samples included in Ancestry’s Reference Panel has increased considerably. However take note that this increase of African samples has been disproportionate. Mostly benefiting the “Benin/Togo”, “Mali” and “Cameroon, Congo & Southern Bantu people” regions.
The title of this blog series was sort of meant to be tongue-in-cheek 😉 as I do believe that Ancestry still offers opportunities for those wanting to learn more about their African lineage. Nonetheless it seems very clear to me that Ancestry’s update may indeed have “killed it“, but only with their new Asian & European breakdowns! However not so with their African breakdown which has taken a big step backwards instead of forwards. At least in most aspects.
In this part 2 I will explore how the changed composition of Ancestry’s Reference Panel as well as Ancestry’s new algorithm may have contributed to this very disappointing outcome. Main topics:
More is not always better: over-sampling for “Cameroon, Congo & Southern Bantu”, “Benin/Togo” and “Mali” causing inflated scores?
What are the ethnic backgrounds of Ancestry’s African samples?
New algorithm has issues with describing mixed/complex lineage?
Last week Ancestry finally rolled out the updated version of its Ethnicity Estimates for all its customers. Sadly the concerns I raised in July have become reality. Many people are now left confused by their revised African breakdown as reported by AncestryDNA.1 Understandably so given the often drastic and seemingly incoherent changes compared with the previous set-up. In this three-part blog post I will argue that Ancestry’s pioneering analysis of especially West African DNA has been downgraded rather than upgraded!
Establishing the accuracy of AncestryDNA’s African breakdown has been the focal point of my AncestryDNA survey which I started five years ago already. From my experience the best indication of such predictive accuracy is obtained by looking at how Africans themselves are being described when tested by Ancestry.2 Which is why I have performed a before & after analysis of 130 AncestryDNA results of African customers from across the continent. Regrettably it turns out that Ancestry’s African breakdown has indeed taken a turn for the worse. In most cases the informational value to be derived from their results is showing a decrease rather than any improvement. See also this overview which contains all their individual results, before and after the update:
This is only a small selection but it illustrates some wider patterns I have observed for other Africans as well. It is not only southern Nigerians who are getting a bad deal from this update! Also people of Senegambian/Guinean descent, people with Akan or Kru lineage, Northeast Africans and also northern Nigerians will see drastic changes in their results. But mostly not for the better…
I am a guy who prefers to see the glass as half full rather than half empty. Which is why I have been surveying AncestryDNA results for so long despite imperfections. After all when Tracing African Roots most people do not have the luxury to be snobbish about admixture analysis. Instead they will want to maximize informational value from any promising source available, again despite shortcomings. Combining research findings in order to achieve complementarity rather than putting all your eggs in just one basket. But right now after this long awaited update my main feeling is that Ancestry has simply broken the glass 😉 . At least in regards to their African “Ethnicity Estimates“. I find it very regrettable to say that currently I do not see much added value in Ancestry’s updated African breakdownand I will not be surveying it any longer. Nonetheless in this three-part blog series I will attempt to point out some redeeming features as well. As I do still also believe that being overly dismissive may deprive you of valuable insights yet to be gained.
Main topics I will cover in this first part:
African breakdown for African AncestryDNA testers
Implications for Afro-Diasporans
Screenshots of updated African AncestryDNA results
Without wanting to give away the cliffhanger ( 😉 ) these will be the topics for part 2 & 3 of this blog series:
In October 2015 I published my first preliminary survey findings based on 23 Cape Verdean AncestryDNA results (see this link). Right now, almost three years later, I have managed to collect a sample group which is four times greater. Consisting of no less than 100 AncestryDNA results of fully Cape Verdean-descended persons! Even though this quadrupled sample size is obviously still limited it will most likely provide a greater insight in the various ways how “Caboverdeanidade” can be described. Genetically speaking that is. And obviously when applying the regional AncestryDNA format, with all its enhanced features as well as its inherent shortcomings 😉
Click on this banner to reach Cape Verde DNA, Inc: the biggest online community of Cape Verdean Genealogy & DNA enthusiasts! On Augustus 4 & 5 a pioneering Cape Verde DNA and Genealogy Conference will be held! See this link for more details.
In this blog post I will discuss the main differences with my previous findings from 2015, which were focused on the African breakdown solely. And in addition I will also present some new statistics and background information on the European and other non-African origins of Cape Verdeans as reported by AncestryDNA. Below an overview of all the topics I will cover:
Background details of my 100 Cape Verdean survey participants
To be Cape Verdean is to be mixed?
Upper Guinean roots = “Senegal” + “Mali”
Beyond Upper Guinea: valid outcomes or misreading by AncestryDNA?
European breakdown reflecting mostly Portuguese ancestry?
“Africa North”, “Middle East”, “European Jewish” and other minor regional scores
Upcoming update of AncestryDNA’s Ethnicity Estimates
Follow these links for my complete survey data & research methodology:
This frequency of regions being ranked #1 (regions with the highest amount in either the African or European breakdown) is perhaps the best indicator of the main ancestral components for my Cape Verdean survey group. However only in an extra pronounced degree. For more nuance see the group averages in the next sections.
Screenshots of individual results (rightclick and open in new tab to enlarge; island origins shown below)
More charts and analysis when you continue reading!
In previous blog posts I have demonstrated how the current African breakdown on AncestryDNA can be very insightful to gain a greater understanding of the regional African roots for people across the Afro-Diaspora as well as actual Africans themselves. Despite several shortcomings as well as the continued need for correct interpretation. My survey findings on a group level have still been reasonably in line with either historical plausibility or actual verifiable genealogy.
A new version of AncestryDNA’s Ethnicity Estimates has been provided gradually (and quietly..) to a subset of Ancestry’s customers for at least since April 2018. I do not have all the needed information in place yet to make a proper assessment. Therefore I reserve my final judgment on this intended update for later. However in this blog post I will discuss some suggestions on how to improve on the current African breakdown hopefully ensuring that Ancestry’s update will be a step forward and not a step backwards. Below a short summary of these suggestions. If you continue reading I will provide more details.
Maintain current coherency of African breakdown and improve by creating less overlapping and more predictive regions
Add more historically relevant African samples to Ancestry’s Reference Panel. In particular from Angola, Burkina Faso, Guinea Bissau/Conakry, Liberia, Madagascar, Mozambique and Sierra Leone.
Create new regions and/or migrations centered around these historically relevant samples.
Bring back the continental breakdown display (subtotals specified for each continent)
Create new African “migrations”, a.k.a. genetic communities. In particular for Nigeria & Ghana, as sufficient customer samples may already exist.
Mention the “aggregate ethnicity estimates” for each migration/genetic community.
Show ethnicity/admixture of shared DNA segments with your matches.
Avoid misleading labeling of ancestral regions. Providing a false sense of accuracy.
Updated results for a Nigerian (Bini, Itsekiri, Urhobo & Isoko)
***(click to enlarge)
Even when these are only individual results this outcome for an actual Nigerian could possibly imply that also for other people of (southern) Nigerian descent Ancestry’s update may lead to a substantial decrease of “Nigeria” amounts. While the “Benin/Togo” as well as the “Cameroon, Congo, and Southern Bantu Peoples” regional scores may drastically increase. Undoing the imperfect yet still reasonably predictive accuracy of the “Nigeria” region in the current set-up. See also: Nigerian AncestryDNA results.
In May 2016 I published the first summary of my Afro-Diasporan survey findings based on 707 results for 7 nationalities (see this blog page). My survey has been ongoing ever since. Right now an update of AncestryDNA Ethnicity Estimates seems even more imminent than it was in 2016 (when it was canceled in the beta phase). So that’s why I will yet again provide a “final” overview of my survey findings 😉 See this link for the first part of my findings which is focused solely on the African breakdown:
In order to provide a broader perspective on the complete DNA make-up of Afro-Diasporans I have this time also analyzed the non-African regional scores on AncestryDNA. Enabling a continental breakdown for my 8 sample groups. Mainly based on 860 results for people from 8 nationalities1. Although the total number of results and nationalities in my survey is even greater.
Generally speaking also the non-African group averages seem to be reasonably in line with historical plausibility. Amerindian, Asian and Pacific trace-amounts are not being left out. These scores are often labeled as low confidence regions and dismissed as just “noise”. Rightfully so in some cases. But given correct interpretation and proper follow-up research at times these scores can still potentially lead you to distinctive ancestors. Furthermore my survey results are now also allowing for a more detailed discussion of the European breakdown as being reported for Afro-Diasporans.
I would like to underline right from the start that my findings are not intended to represent any fictional national averages! The group averages I have calculated for my sample groups are neither absolute or conclusive but rather to be seen as indicative. Obviously several shortcomings may apply. One main aspect to take to heart is that there will always be individual variation around the mean. Given correct interpretation I do believe these group averages suggest insightful tendencies though for each of my 8 sample groups. They also mostly comply with the findings of admixture studies published in peer reviewed journals, or at least the ones I am aware of.2
In 2013 AncestryDNA updated their Ethnicity Estimates to include a detailed breakdown of West African DNA. Pioneering when compared with other DNA testing companies. Soon afterwards I started collecting AncestryDNA results in an online spreadsheet in order to conduct a survey of the African regional scores being reported by AncestryDNA.At first only for people of the Afro-Diaspora and later on also among Africans. My main research goal has always been to establish how much the AncestryDNA 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.
In May 2016 I published my first summary of my Afro-Diasporan survey findings based on 707 results for 7 nationalities (see this blog post). My survey has been ongoing ever since. Right now an update of AncestryDNA’s Ethnicity Estimates seems even more imminent than it was in 2016 (when it was canceled in the beta phase). So that’s why I will yet again provide a “final” overview of my survey findings 😉 . Mainly based on 1,264 results for people from 8 nationalities. Although the total number of results and nationalities in my survey is even greater.
A major addition is the inclusion of 45 Brazilian results. Their predominant Central African profiles (as measured by both “Southeastern Bantu” and “Cameroon/Congo”) are quite striking when compared with my other sample groups. This outcome reinforces how the African breakdown onAncestryDNA has been reasonably in alignment with historically documented origins of the Afro-Diaspora. Unlike any other DNA testing platform I’m aware of and therefore not to be lightly dismissed despite inherent imperfections.
In the second part of this blogseries I will also provide an overview of the non-African regions (Amerindian, Asian, Pacific etc.) being reported for Afro-Diasporans. As well as a more detailed analysis of their European breakdown.
“This frequency of regions being ranked #1 (regions with the highest amount in the African breakdown) is perhaps the best indicator of which distinct African lineages may have been preserved the most among my sample groups.”
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:
I have created a new page featuring the AncestryDNA results for West Africans from the following countries: Liberia, Ivory Coast, Burkina Faso, Ghana, Togo & Benin. I will create a new section for the remaining part of West Africa (Upper Guinea) shortly. The number of results I have collected so far might be minimal but already my survey findings turn out to be quite insightful. I also provide some statistical data, analysis and relevant context. Follow this link to view the page:
In addition I also discuss the implications these findings might have for Afro-Diasporans in an attempt to improve proper interpretation of their West African regional scores, in particular for “Ivory Coast/Ghana” and “Benin/Togo”.One of these implications I will also discuss in greater detail in this blog post:
“Benin/Togo” is also predictive of Ghanaian & Nigerian DNA
The so-called “Benin/Togo” region seems to be quite predictive of Beninese origins (based on two results). However in addition ancestry from eastern Ghana and southern Nigeria might also be described by this region. You will need to perform your own follow-up research in order to find out more specifics.