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:
Table 1 (click to enlarge)
Table 2 (click to enlarge)
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 Guinean macro-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.
Whenever possible DNA matches should of course always be placed in their proper genealogical & historical context. The banner displayed above belongs to one of several Facebook groups specializing in this field for Jamaicans. Check out the following helpful resources on Jamaican genealogy & history. Not meant to be an exhaustive overview but just to get you started.
- Jamaican Family Search (VERY extensive!)
- Slaves and Slavery In Jamaica (JFS)
- Morovian Church Records St. Elizabeth (African origins sometimes indicated!) (JFS)
- Jamaica DNA Roots (Facebook)
- Jamaican Genealogy Resources (Facebook)
- Jamaica DNA Project – Y-DNA & mtDNA Research (FamilyTreeDNA)
- Early Caribbean Digital Archive (ECDA)
- A Tale of Two Plantations (detailed genealogy for Mesopotamia plantation)
- Bibliography of materials on Jamaica (1650-1834) (The Zamani Reader, also check out “custom bibliographies” for more material)
- Parishes of Jamaica across time (Prestwidge) (useful maps!)
- Jamaican Genealogy Part 2 – How to build your Family Tree (Blog/Youtube)
While analyzing the DNA matches of my Jamaican survey participants I have always taken a cautious stance when deciding on their most likely background. Going by any clues given, but in particular: plausible admixture. Not only “100% African” but also plausible regional admixture combinations. Combined with plausible surnames. As well as actual birth locations and other relevant profile details (whenever available). My methodology is described in more detail in the last section of this blog post. But already I would like to underline that my categorization of DNA matches by either nationality or ethnicity is indicative only. Obviously I did not have perfect and complete information at hand for each single DNA match. While the number of DNA matches to be analyzed often remained quite high even after automated filtering and sorting in Excel. Instead of aiming for 100% accuracy I therefore processed the data on a best effort basis to get a general idea.
Other considerations to keep in mind when dealing with DNA matches:
Table 1.1 (click to enlarge)
“Identical by Descent (IBD) refers to a segment that you share with someone from a common ancestor within the genealogical timeline.
Identical by State (IBS) is used to describe a variety of scenarios where the segment cannot be tracked to a common ancestor, including IBC and IBP.
Identical by Chance (IBC) describes a segment where an accident of recombination means that a segment matches, but this is not a genuine match.
Identical by Population (IBP) refers to segments that are widely shared among populations, to the extent that they are not genealogically useful – e.g. in endogamous populations. ” (source: DNA Painter Glossary)
The main thing to consider when reviewing your DNA matches is establishing whether your DNA matches are indeed “the real thing”. In other words: “Identical By Descent” (IBD) and not just random “Identical By State” (IBS) matches. Getting your parents tested or any other relatives of older generations will increase your ability to be more certain about the genetic inheritance of any given reported DNA match. So-called population matches (IBP) might be most tricky to distinguish. But also the size of the shared DNA segment will be indicative to find out if your DNA match could in fact be a so-called false positive. It is well advised to carefully read the Predicted Relationship Info given by Ancestry and especially the confidence score they will assign to your DNA matches.
As shown above in Table 1.1 increased chances of false positives exist in particular for smaller matches with a shared DNA amount of in between 6 cM – 16 cM. Other DNA testing companies tend to apply similar criteria. Although with some differences in actual thresholds. For example on 23andme the cut-off for DNA matches being reported starts at 7 cM and not 6 cM. Also a shared DNA amount of 10 cM and greater is often considered quite reliable already. With an estimated IBD probability higher than 50%, unlike what is stated in table 1.1. However during my survey I mostly came across smaller DNA matches. While DNA matches of around 10 cM let alone greater than 20 cM (“close matches” in table 1) were much less frequent. These latter matches would naturally be indicative of the most robust matching patterns.
Despite a lower confidence score I do believe that these smaller matches may still also be informative. Even when I suspect that especially matches of in between 6 cM – 7 cM are usually population matches (IBP)2 or just random matches (IBC). And again such matches do call for very careful scrutiny. In many cases smaller matches may indeed not be genealogically meaningful. But they can provide extra historical perspective when reported in distinctive frequencies!
Also to be taken into account then is the expected time frame for these matches. Naturally shared DNA with matches which are to be traced back to the late 1600’s or early 1700’s will tend to be greatly diluted and fragmented due to recombination across the generations. Which would be in line with smaller sized DNA matches. The larger sized matches (>10cM) being suggestive rather of relatively recent ancestors from the late 1700’s or even 1800’s. For more discussion see:
- Identical by Descent Matches (ISOGG)
- How Phasing Works and Determining IBD Versus IBS Matches (DNAeXplained)
- The Danger of Distant Matches (The Genetic Genealogist)
Ethnic composition of Ancestry’s customer database matters!
Chart 1.1 (click to enlarge)
Another aspect to keep in mind is that my survey findings are based on the scanning of DNA matches I performed in September 2019. Therefore the matching patterns I am describing in this blog post are representing a snapshot of Ancestry’s customer database in the autumn of 2019. Because of ever increasing popularity of DNA testing it is inevitable that when performing the exact same exercise in 2020 or 2021 my survey findings will look quite different. Especially quantitatively speaking. Then again I imagine that quality-wise most of the matching patterns would still broadly be the same.
According to Ancestry’s own information a staggering 16 million DNA tested people are included in their customer database already! Easily making Ancestry the largest DNA testing company in the world (see this link or also this one). In itself this provides an unprecedented platform to establish statistically meaningful matching patterns for my survey group. Basically speaking 30 Jamaicans are being compared with over 15 million other DNA tested people! To see if they have any shared DNA segments suggestive of common ancestors. Of course individual variation will still be relevant. But the wider implications of such an undertaking are already quite significant I would say.
Then again the composition of Ancestry’s customer database did greatly influence the outcomes. Because Ancestry is an USA based company it is only natural its customers are overwhelmingly American and mostly of European descent. Luckily the USA is home to many 1st or 2nd generation migrants from all over the world who also take DNA tests. Which still enables a fairly global representation within its database. Incl. many Jamaicans! Plus lately Ancestry has also expanded into foreign markets where likewise also people of migrant descent are taking DNA tests.
Nonetheless because of this skewed database factor for Afro-Diasporans in general there has always been an inherent bias towards being matched with White Americans or even Europeans. Rather than with actual Africans. This goes not only for Ancestry but also for other DNA testing companies. Especially in the early days (2010-2017) when DNA testing was not yet as popular as it now is among minorities. While in particular African DNA testers were very rare. For more details see:
- The ethnic breakdown of 23andMe customers in 2011 (Gene Expression)
- 2017 was the year consumer DNA testing blew up (Technology Review)
- DNA databases are too white. This man aims to fix that (Technology Review)
Even though it would have been interesting I did not attempt to single out British or Irish matches for my survey participants.3 But if I had done so undoubtedly they would turn out to be overwhelmingly numerous. In fact even the average number of Jewish matches (49) was higher than the average number of African matches (29). Despite minuscule Jewish admixture (0.2% versus 80% African on average, see Table 1)! Still while performing my survey I was pleasantly surprised to see that the number of African matches is steadily on the increase when compared with previous years.4
This skewed database effect also holds true for Africa itself though! It is essential to be aware that Ancestry’s customer database will not be perfectly representative of all your possible African lineage. Certain African nationalities (esp. Nigerian & Ghanaian) will be over-represented due to their relative greater migration presence in the USA, Canada, Europe or other places where the AncestryDNA test was purchased. 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. See also my main findings in Table 2.
Although by now I actually have personally seen African Ancestry profiles from almost all countries on the continent. So overall the African coverage in Ancestry’s customer database is already quite impressive. But just not so proportionally speaking. This situation increases the odds of being matched with your Nigerian lineage for example. But it does not potentially invalidate that you might still also have Beninese/Togolese or Central African ancestry in addition. For this you also need to take into account regional admixture.
Your matches may be related to you in unexpected or intricate ways
Perhaps redundant but it might still be worth reminding that the MRCA‘s (most recent common ancestors) shared between my survey participants and their matches will not per se have been of the same background as their matches themselves. Especially due to ongoing migrations there are usually several possible ancestral scenario’s to consider whenever you get “matched” with someone. Assumptions about the direction of gene flow may be proven wrong after follow-up research. Context is everything and historical plausibility combined with solid genealogical research should be leading instead of wishful thinking or unfounded conjecture.
I find that the frequency of inter-ethnic unions occurring in Africa itself is greatly underestimated by many people. Most likely due to modern-day urbanization this phenomenon has increased even more so in the last generations. Very recently researchers found that the rate of inter-ethnic marriage might be as high as 20% in several African countries! In fact 15 of the matches I found were most likely people who were born to parents from two different African countries. Going back further in time there would also have been plenty of occasion for ethnic mixing though. Even in rural places. The widespread practice of polygamy probably served to boost this. Keeping in mind also that ethnic identity in most African cultures is quite flexible and often passed on through only one parental line. A study performed in southeast Nigeria for example estimated that inter-ethnic gene flow of 10% per generation might have been common. See also:
- Little genetic differentiation as assessed by uniparental markers in the presence of substantial language variation in peoples of the Cross River region of Nigeria (Veeramah et al., 2010)
- Interethnic and interfaith marriages in sub-Saharan Africa (J. Crespin-Boucaud, 2019)
2) Combine DNA matches with admixture analysis for more insight
Table 2.1 (click to enlarge)
It is often said that admixture analysis should be taken with a grain of salt.5 Rightfully so as it can only provide (informed) estimates about your ancestral make-up. Then again valuable insights are still to be gained when these estimates are interpreted correctly. However we might also say that neither DNA matches nor admixture analysis will be 100% accurate. As in fact DNA matches can be misleading as well when there is no confirmed paper trail or when there is a lack of relevant context or when you are dealing with smaller matches (<10cM) which possibly might be false positives.
I personally always aim for maximizing informational value despite imperfections. From my experience combining your admixture results with your DNA matches will often lead to enhanced insights and complementarity. Pinpointing exact ethnicity is often a major shortcoming of admixture analysis. But this can be compensated by finding relevant DNA matches. On the other hand any over-reliance on DNA matches might lead to a disproportional outlook on your complete ancestry. Some ancestral lines being more “matchy” than others as a result of an ethnically skewed customer database. And this may then be corrected by your admixture results.
These admixture results may be imprecise but still should enable you to (roughly) distinguish between major and minor sources of ancestral origins (both continental and subcontinental!). This is why I have chosen to also take admixture levels into consideration during this survey of DNA matches.6 Unless stated otherwise all regional admixture scores will be based on AncestryDNA’s 2013-2018 version. Despite its own shortcomings I do believe this old version is still better equipped to describe Jamaica’s known African regional roots than Ancestry’s updated versions (see this link).
Going by the correlation coefficients shown in Table 2.1 we can see that in almost all cases a positive correlation was obtained. Implying that usually a greater number of matches was reported for people who also had an above average amount of associated admixture. However a strong degree of correlation (>0.7) only seems to apply for South Asian, Jewish and African matches/admixture. Actually for Ghanaian matches/admixture it was also still quite reasonable (>0.4). However for other types of admixture the correlation was rather weak (<0.3). While for “Benin/Togo” it was in fact negative! The latter outcome vindicating my previous blog posts about “Benin/Togo” being one of the most ambivalent regions in AncestryDNA’s African breakdown. After all it was also predictive of both (southern) Nigerian and (eastern) Ghanaian lineage. And therefore also (partially) correlating with both Nigerian and Ghanaian matches.7
Correlation does not imply direct causation. Several other variables might have impact as well. However being aware of the approximate degree of correlation can be useful! First of all to get greater insight into the predictive accuracy of the various regions available in AncestryDNA’s breakdown. Weaker correlation being suggestive of a weakly defined region which also covers other types of admixture and associated DNA matches. Furthermore it can be helpful to get the scoop on the odds of corroborating regional admixture with associated DNA matches.
In other words, if for example one of my Jamaican survey participants happened to have an above average degree of Nigerian admixture this did not per se translate into also having an above average number of Nigerian matches. Because the correlation was pretty weak (0.18). Probably because “Nigeria” (2013-2018 version) did not have a very solid predictive accuracy.8 But people with above average African admixture did often clearly receive a greater number of African matches. I will discuss these outcomes in more detail in following sections.
Based on my current findings I can already say that admixture results and DNA matches can be of mutually reinforcing value indeed. For example during my survey I was often able to corroborate even trace amounts of admixture by finding associated DNA matches. In particular for Jewish and South Asian ancestry. But also for example for small amounts of “Senegal”. Also I could verify that “Ivory Coast/Ghana” (2013-2018 version) was indeed predictive of both Ghanaian and Liberian DNA (see this blog post). However for Jamaicans apparently more so correlating with Ghanaian DNA matches than with Liberian ones.
3) West African matches
Table 3.1 (click to enlarge)
Table 3.2 (click to enlarge)
Many interesting details may be gleaned from the first overview above. It shows the most likely backgrounds of all the West African matches I was able to find for my Jamaican survey participants. I will start off with noting that my findings are clearly indicating that Jamaica’s West African predominance in regional admixture is also mirrored in DNA matches. This outcome may serve as an illustration of how sub-continental admixture results can be of great informational value. On condition of correct interpretation! In this case facilitated by the usage of a macro-regional format.
Looking more closely into the geographic/ethnic distribution of all the 861 African DNA matches I found for my survey participants we can establish that the proportion of Lower Guinean related matches is 87% of all African matches. That proportion being equal to 755/861. Which roughly corresponds with the almost 70% Lower Guinean share I found during my previous survey based on 100 Jamaican AncestryDNA results (see table 3.2). This latter survey being based on regional admixture according to Ancestry’s 2013-2018 version. And with the African breakdown being scaled to 100%.
Lower Guinea is a historical term which refers to the area in between modernday Liberia and Cameroon. Covering both Ghana and Nigeria therefore. But excluding Upper Guinea, which extends from Senegambia into Sierra Leone. The much lower share of Upper Guinean matches (40/861=5%) is indeed in line with historical records which mention that Jamaica’s West African heritage is overwhelmingly from the area in between Ghana and Nigeria. This knowledge has now been corroborated by both regional admixture analysis as well DNA matches! Very useful also to compare with a similar survey I did among 50 Cape Verdeans. Unlike Jamaicans for them a prevailing Upper Guinean share was to be expected for historical as well as geographical and cultural reasons. And this was also convincingly demonstrated through both regional admixture and DNA matches! See also:
As a word of caution I should repeat that Ancestry’s customer database has an ethnically skewed composition. With especially Nigerian & Ghanaian customers most likely being over-represented. It might not just be a coincidence that the top 4 of West African countries of origin for African migrants in the USA is exactly the same as the one among the West African DNA matches I found: 1) Nigeria; 2) Ghana; 3) Liberia; 4) Sierra Leone (compare table 3.1 with chart 1.1). Then again there is plentiful historical evidence as well as genetic clues (regional admixture) to justify the ranking of these matching patterns as well!
Leaving aside the absolute numbers there is not that much difference in matching strength between these top 4 countries. The average shared DNA amount being around 8 cM for all of them, which is quite substantial. And also their share of matches greater than 10 cM is comparable (10%-20%). Especially the occurrence of close matches (>20 cM) will be a solid indicator of more robust matching patterns. These were quite rare as I only found five of them out of a total of 861 African DNA matches. Which is not that surprising given the implied rather recent timeframe (early 1800’s?). Still probably very telling that these close matches were Nigerian (2x), Ghanaian 2x) but also in fact Sierra Leonean (1x)!
For the Sierra Leonean as well as Liberian matches I have checked for the possibility of Krio lineage whenever I could. Based on regional admixture as well as surnames mostly. But also any other clues given. As this might imply more complex ancestral scenarios. Including shared Jamaican Maroon ancestors transferred to Sierra Leone! However except for one case I do not think any of the Sierra Leonean matches were Krio related. This also goes for the close match (23cM reported for JAM27) who showed a “Mali” score of 88%! Which is in line with Ancestry’s 2019 update resulting in very pronounced “Mali” scores for Sierra Leoneans as well as Liberians. I did however find two most likely Americo-Liberian matches out of a total of 36. See also:
- Krio from Sierra Leone: Afro-Diasporans with a twist?
- The Yardee Connection (Patriotic Vanguard)
- Trans-Atlantic Maroon Connection Project
Aside from 22 Sierra Leonean matches actually matches from other parts of Upper Guinea were quite rare. And whenever I could come up with a more specific background the average shared DNA amount was rather low. With a high share of matches smaller than 7 cM. Increasing the odds of either false positives or population matches. Still interesting that matches from most likely Mali would be somewhat more numerous than from Senegal. This Sierra Leonean predominance of Upper Guinean matches probably explains why the correlation I found between Upper Guinean admixture (“Senegal” + “Mali”) and Upper Guinean matches was only moderate (0.25, see table 2.1). After all in Ancestry’s 2013-2018 version Sierra Leonean DNA was (partially) described by “Ivory Coast/Ghana” in addition to also “Senegal” and “Mali” (see this blogpost).
Also noteworthy that I could only detect 3 Fula matches. I do suspect that a few of the North & East African matches might actually also be Fula related (see section 5). But Fula matches were much more numerous during a similar survey of African DNA matches reported for 50 Cape Verdeans: 95 strictly Fula as well as 45 Hausa-Fulani out of a total of 437 matches (see this overview). Also among African Americans I am usually able to find numerous Fula matches. That they should be largely absent for Jamaicans is quite telling therefore. Of course my findings are only preliminary but most likely this outcome is already indicating how the relatively greater match strength for Lower Guinea among Jamaicans is in line with historical plausibility. See also:
Nigerian ancestry greater than Ghanaian ancestry?
Table 3.2 (click to enlarge)
The Nigerian DNA matches for my 30 Jamaican survey participants were even more frequent than I had expected beforehand. Nigerian matches make up more than half (483/861) of the total number of African matches I found! Furthermore the average number of Nigerian matches (16) is twice as big as the average number of Ghanaian matches (7). This outcome adds an intriguing twist to the ongoing debate on whether Jamaicans as a whole are more so of Nigerian descent. Or rather that Ghanaian ancestry is more significant, overall speaking. I do not believe my findings will settle things conclusively. Based on this information alone one cannot immediately assume that Nigerian lineage is also about 50% of Jamaica’s African total ancestry! However with careful interpretation this greater Nigerian matching strength does seem to have wider implications.
We should first of all again take into account that Ancestry’s customer database most likely contains more Nigerian than Ghanaian DNA testers. Although from what I have seen in my previous African surveys really both countries are quite well-represented already. My final sample size for Nigerian AncestryDNA testers being n=87 and for Ghana it was n=42 (see this sheet). Which is again practically twice as much. Perhaps no coincidence given that Nigerian migrants (327k) are also about twice as numerous as Ghanaian migrants (155k) in the USA (see chart 1.1).
So measuring matching strength by sheer numbers only might be a bit misleading as it seems that right from the start the matching odds are stacked in favour of Nigerians. Ideally you would want to measure matching strength by comparing with a database which contains an exactly equal number of Nigerians and Ghanaians. And of course also an exactly equal number of any other historically relevant source population for Jamaicans. As this would give a fair shot for any kind of match to occur. Going by other details such as average shared DNA (around 8-9cM) and number of close matches (2x) there is actually not that much difference between the Nigerian and Ghanaian matches I have found. I was able to find Nigerian matches for all of my survey participants. While only for 1 person I could not find any Ghanaian matches (see table 3.2).
Then again there is compelling historical evidence which suggests that these matching patterns are still more or less representative. At least ranking wise. In particular the fact that slave trade by way of the Bight of Biafra (=southeast Nigeria) was greater than from the Gold Coast (=Ghana). See also this overview which I have discussed in greater detail already during my survey of 100 Jamaican AncestryDNA results. Furthermore the relatively late time periods of arrival and also greater female ratios for captives from the Bight of Biafra might have contributed even more so to leaving a greater impact on Jamaican genetics. See also:
What does regional admixture say?
Individual screenshots (rightclick and open in new tab to enlarge)
For an additional perspective it is of course also useful to consider the regional admixture estimates for my Jamaican survey participants. In my earlier survey among 100 Jamaican AncestryDNA results it was already established that previously “Ivory Coast/Ghana” made up the greatest part of the African breakdown. Measured both by group averages as well as by frequency of being ranked #1. This outcome was also reflected among this smaller survey group (n=30) which showed an average of 21% “Ivory Coast/Ghana” (unscaled, see table 3.2).
On the other hand it has also been pointed out already that the predictive accuracy of the “Nigeria” region used to be inadequate. Nigerian DNA was in fact also covered to a large degree by “Benin/Togo” and “Cameroon/Congo”. Which is why the group average of 16% “Nigeria” (2013-2018 version) was almost certainly an underestimation of the genuine extent of Nigerian ancestry among my survey participants. For example two survey participants (JAM03 & JAM29, see this sheet) did receive several Nigerian DNA matches despite having zero “Nigeria” regional admixture according to the old 2013-2018 version!
Regrettably Ancestry’s subsequent updates in 2018 & 2019 have greatly complicated things by basically ruining its ability to report a reasonable estimate of Ghanaian lineage.9 I have actually also kept score of the updated “Nigeria” and “Ghana” scores for my 30 survey participants. They can be seen within my spreadsheet. And they are also to be seen in the screenshots shown above. Results according to the 2013-2018 version and 2019 update are being shown side to side for the same survey participant. The new group average of “Nigeria” is a convincing 46%. Which seems to align pretty good with the predominance in Nigerian DNA matches as well. But the new group average for “Ghana” has been reduced to a mere 3%. Which is clearly an aberration on Ancestry’s part.
If you look into the individual results it seems that often the increase of “Nigeria” has come at the price of a steep decrease in “Ghana”. This is especially apparent when reviewing the results which used to have a primary “Ivory Coast/Ghana” score. This was true for 12 of my 30 survey participants. A share of 40% (12/30) which is in line with my overall survey findings (n=100, see this chart). However after the 2019 update “Nigeria” is consistently being reported as primary region for everyone. In clear contradiction of how Jamaicans are mainly Ghana & Nigeria hybrids based on historical and other clues. Possibly Nigerian lineage prevailing somewhat over all. But certainly showing much greater variation than reflected in this newly updated African breakdown.
All in all it seems to me that a realistic estimate of Nigerian admixture among Jamaicans is probably somewhat in between the level reported in Ancestry’s 2013-2018 version and the 2019 update. Perhaps on average around 30-40% of total African ancestry? While a realistic estimate of Ghanaian admixture is probably much closer to the old 2013-2018 version, or even higher. When also taking into account non-Akan lineage from the east and north total Ghanaian admixture might be around 25-35%?
I am just speculating of course. But it is useful to also take into consideration what is being reported on 23andme for Jamaicans. As actually also on 23andme “Nigerian” admixture exceeds “Ghana, Liberia, Sierra Leonean” estimates (see this table). Obviously 23andme’s African breakdown has its own shortcomings and despite similar labeling these categories might not be perfect equivalents (due to differences in reference samples and algorithm). Still all of this does add to the growing impression that Nigerian ancestry might indeed be somewhat more prevalent than Ghanaian ancestry for Jamaicans. Even when the approximate degree is yet to be established.
” On 23andme Igbo’s seem to have as many Jamaican IBD matches as Ghanaians (personal observation). Suggesting close ancestral connections in comparable measure. Future DNA studies focusing on IBD matches for Jamaicans based on much more extensive African databases could undoubtedly provide more clarity.” (Fonte Felipe, 2015)
It is interesting to also revisit earlier DNA studies dealing with this topic, based on maternal haplogroups. I have reviewed these studies in 2015 (see this blogpost). I do still commend the authors for their very thorough and detailed treatment. And especially for also integrating historical demography and creolization theories in a very insightful manner. However their main findings appear to be in need of reevaluation. Perhaps also the methodology being used to assign certain haplogroups to particular areas within Africa has become outdated by now.
Amazingly nearly 50% of Jamaican maternal haplogroups were being associated with the Gold Coast and only 6% with the Bight of Biafra (see this table). But frankly such an outcome seems untenable in light of new and more encompassing genetic evidence. Given my own survey findings based on both regional admixture and DNA matches I would argue that their description of the historical evolution and composition of Jamaica’s enslaved population is up for reassessment. And even more so of course when focusing on the genetic heritage which has been left behind.
Naturally this is an ongoing research effort and new insightful findings might surface in the near future. Also I like to stress my discussion in this section is based on group averages and generalized tendencies! This is not to deny individual variation. In fact I will discuss the occurrence of substructure in my survey group further below in section 6. As it seems that Nigerian DNA matches are more frequent among a subgroup of my survey participants. Also noteworthy that actually for one survey participant (JAM08) the number of Ghanaian DNA matches (15) was greater than the number of his Nigerian matches (14). While for another person (JAM17) the number of either matches was equal (8). This provides a very important clue also in light of their primary old “Ivory Coast/Ghana” scores! For more discussion see:
- Ancestry’s 2019 Update: Back on Track Again?
- 100 Jamaican Ancestry results (2013-2018) (scroll down to section 7 for Ancestry’s update and section 6 for my 23andme survey)
Primacy of Igbo DNA matches: in line with historical expectations?
Table 3.3 (click to enlarge)
“Throughout the Igbo diaspora […] Jamaica was the single most important destination in this massive and violent forced migration. For example, more than 300,000 enslaved Biafran Africans, or ten times the number of those taken to Virginia, were landed in this one island. (D. Chambers, 2016, p.158)”
I like to reiterate again that Ancestry’s customer database is skewed in favour of certain African migrant nationalities. In particular Nigerians. And furthermore most likely also certain Nigerian ethnic groups might be over-represented. It being well-known that especially the Igbo are prone to migrate. Not only within Nigeria but also to foreign countries, such as the USA. I have no idea what approximate share of Nigerian-Americans might be Igbo. But it seems likely that they are a majority. Also given that the Igbo people are the third biggest ethnic group of Nigeria. From anecdotal evidence I am guessing the Yoruba and perhaps also the Hausa-Fulani might have a greater presence in the UK. But again I have no hard data for this. Either way it can easily be verified from table 3.3 that more than half of the Nigerian matches appear to be Igbo (253/483 = 52%). The second biggest subgroup at some distance being Yoruba with a share of around 13% (62/483).
I should also restate my earlier disclaimer that the ethnic backgrounds mentioned in this overview are only intended to be indicative! I am going especially by distinctive surnames. Fortunately these are often quite specific to certain ethnic groups within Nigeria (see section 8). But for example just because someone happens to have a seemingly Igbo surname does not per se mean that both of his parents or all 4 of his grandparents etc. would be Igbo as well. Again the frequency of inter-ethnic unions is not to be underestimated! Also in previous generations and beyond family knowledge even.
Whenever I was doubtful about a surname I have not attempted any further ethnic categorization. This applies to about 116 Nigerian matches. But actually I suspect most of them might still be Igbo or from southeastern Nigeria (due to additional “Cameroon, Congo & Southern Bantu” scores). Also taking into account the possibly 21 non-Igbo matches from Southeast Nigeria (based on surname) it seems quite apparent that the Bight of Biafra connection for Jamaicans is reflected in abundant DNA matches. Which serves as a very valuable corroboration! Furthermore the clear predominance of Igbo matches (caveats to be kept in mind) makes for an useful argument in the whole randomization versus clustering debate when it comes to identifying the specific African lineage of Afro-Diasporans. See for example:
- Ethnic identities of African-born slaves: valid or imposed? (Tracing African Roots, 2015)
- “A Presumptive Evidence?” An Introduction to the Historiography of African Provenance Labels in the Early Modern Era (The Zamani Reader, 2016)
- The Links of a Legacy – Figuring Slave Trade to Jamaica (Chambers, 2007)
Plentiful historical evidence exists which may further illuminate these findings. Especially research performed by Douglas Chambers is recommended reading! See also references below. One should keep in mind though that even if the Igbo were a majority among Bight of Biafra captives. Still also other southeast Nigerians (non-Igbo) were involved as well. Often referred to as “Moco” and assumed to be mostly Efik/Ibibio or Ijaw. But probably also including related and neighbouring people. Perhaps as far back as the Cameroon highlands. Based on the extensive Runaway Slave Advertisements for Jamaica this share of non-Igbo southeast Nigerians might be as high as 40% (among those shipped from the Bight of Biafra, see also table 4.2). Such backgrounds are already visible in my table 3.3. Probably with greater migrant presence in the USA such matches would be even more noticeable. Further reading:
- Chambers, D. (2002). “Frequency of Igbo among Biafran Africans in the Diaspora”
- Chambers, D. (2014). “Biafran African Runaways in 18th-Century Jamaica and Saint-Domingue: Evidence for an African Ecumene,” Igbo Studies Review, (2), 1–20.
- Chambers, D. (2016). “The Igbo Diaspora in the Era of the Slave Trade” in T. Falola and R. Chijioke Njoku, eds., Igbo in the Atlantic World: African Origins and Diasporic Destinations, pp. 156-170
- The Igbo Connection for Virginia & Virginia-Descendants [also deals with Jamaica!]
Table 3.4 (click to enlarge)
For a majority of my survey participants Igbo matches were most numerous. Especially when only looking into their Nigerian matches. This outcome will usually be convincing testimony of a substantial Bight of Biafra connection. Then again most people did have Nigerian DNA matches from other ethnic groups as well. In particular Yoruba ones. Going by distinctive surnames I also detected several most likely Edo/Bini, Urhobo and Ijaw matches. Some of these matches were quite small though (<7 CM). And therefore presenting greater chances of being mere population matches (IBP) or even just false positives. Still they should be indicative of generic roots hailing from southern Nigeria.
Yoruba matches (62) were overall clearly secondary to Igbo matches (253). However most survey participants did receive at least one or more Yoruba matches. And going by average shared DNA (around 8.5 cM) and other measures the difference in matching strength is quite comparable actually to the Igbo matches I found (see table 3.3). Amazingly also including 1 close Yoruba DNA match (23 cM)! Furthermore for three persons (JAM08, JAM12 and JAM19) the number of Yoruba matches was actually greater than the number of Igbo matches. For one of them additionally also 3 Edo/Bini matches showed up! Very remarkable given my overall findings. I suppose this could count as an extremely useful clue that their Nigerian lineage is inclusive of Yoruba ancestry as well. Most likely to a greater degree than what is average among Jamaicans. And possibly but not per se also relating to Yoruba contract labourers from the mid 1800’s. Who apparently settled mainly in Westmoreland and Hanover. Although the earlier presence (1700’s) of Yoruba or “Nago” captives in Jamaica has also been well documented actually. See also:
- African Retentions in Jamaica – Ettu & Nago
- Ethnic origins of Jamaican Runaway Slaves (incl. 109 “Nago”) (Chambers, 2007)
- Igbo, Yoruba or Hausa-Fulani? Nigerian AncestryDNA results 2013-2018
It is quite striking that I only came across one possible match from northern Nigeria. Probably Hausa-Fulani, but I have no certainty. This does go along with the very minimal number of Fula matches (3x) I found as well. It probably also reflects how it is overwhelmingly southern Nigeria which was involved in Trans-Atlantic slave trade with Jamaica. And not northern Nigeria. Then again northern Nigerian DNA testers might also just be quite rare at this moment. Intriguingly I did manage as well to find one quite likely Igala match with a good amount of shared DNA (9 cM). Suggestive of Middle Belt connections. Even when I suppose this match could also be partially or distantly Igbo. The Igala being situated right to the north of Igboland. It is hard to find a map which does full justice to Nigeria’s immense ethnic diversity. But for greater visualization see:
Ghana matches not only Akan but also often Ewe
Table 3.5 (click to enlarge)
- Spreadsheet survey group sorted on number of Ghanaian matches (Liberian matches also listed!)
In popular imagination Ghanaian lineage for Jamaicans is often equated with Akan ancestors or better yet Ashanti ones (a subgroup of the larger Akan meta-ethnicity). Probably because the Akan are considered to have played the most evocative role in Jamaican history by many people. Especially during the Maroons Wars. Often referred to as Coromantee, back then. But it is usually not taken into consideration that the Maroons have always formed a small minority of the Jamaican population (at least going by official census). And their distinctive formation as a Jamaican subgroup mostly took place in the early/mid 1700’s. Bypassing therefore the bigger waves of African captives from especially Bight of Biafra but also Central Africa arriving in Jamaica in the late 1700’s and early 1800’s. Furthermore the “Coromantee” label may actually at times also have been applied for non-Akan people. See also:
- 1788 Census showing Maroons to number only 1326 among a total population of 254,000 (Jamaican Family Search)
- Jamaican Maroons Research (Harcourt Fuller)
- “A Presumptive Evidence?” An Introduction to the Historiography of African Provenance Labels in the Early Modern Era (The Zamani Reader)
Going by historical sources it was already known that Gold Coast captives were however of many distinctive ethnic origins. Certainly not restricted to only clustered Akan backgrounds. As perhaps suggested by the ubiquitous Coromantee label. They were hailing from various parts of Ghana and not just the Akan speaking south and center of the country. But also beyond. Into neighbouring Burkina Faso in the north, Togo to the east and Ivory Coast to the west. This is also reflected in my overview of DNA matches above. With most likely Akan matches still being the biggest group (85/208 = 40%). But also especially Ewe matches being well represented (45/208 = 21%).
My previous disclaimers about indicative surnames and skewed ethnic representation within Ancestry’s customer database are still to be kept in mind of course. I have a strong suspicion for example that Ghanaian migrants in the USA or Europe are predominantly from the south of the country (see p.11/12 of this paper). Either Akan, Ga-Adangbe or Ewe. But northern Ghanaians are probably underrepresented on Ancestry because they tend to migrate less frequently (at least to the West). Still very useful to see a few Northern Ghanaian matches. Confirmed even in two cases by way of the laudable TAKIR project. And even one match from possibly Burkina Faso! Going by regional admixture it might very well be that “Mali” scores (2013-2018 version) for Jamaicans were often suggestive also of Gur speaking lineage from northern Ghana and beyond into Burkina Faso and surrounding areas. As indicated also by a high frequency of so-called “Chamba” captives in Jamaican runaway advertisements. See also:
- West African Results (Upper Guinea) (2013-2018)
- Northern Ghana Family Reunification Project (TAKIR)
- Chart featuring the ethnic origins of runaway slaves in Jamaica, incl. 169 Chamba! (D. Chambers, 2007)
But of course “Ivory Coast/Ghana” used to be the main region for establishing Ghanaian admixture. And in Ancestry’s 2013-2018 version “Ivory Coast/Ghana” was especially predictive of Akan lineage but also Liberian ancestry actually! In addition it was also prevalent to a lesser degree among Sierra Leoneans. Which complicates a straightforward interpretation. However having this DNA matches overview in place does illuminate things! Akan lineage among Jamaicans certainly looks more significant than Liberian lineage. As was to be expected already from historical sources. Not only when judging from the number of DNA matches (85 vs. 36). But also actually when going by the correlation between regional admixture and number of DNA matches. As was already mentioned in section 2 “Ivory Coast/Ghana” scores (2013-2018 version) were correlating more so with Ghanaian matches (0.43) than with Liberian ones (0.20). Even when in fact it was positive also for Liberians.10
Still the number of Liberian DNA matches in itself is not small. It was actually the third biggest group after Nigerian and Ghanaian matches. Intriguingly my survey participant (JAM15) who showed the highest “Ivory Coast/Ghana” score (63%) had both Ghanaian (7) and Liberian matches (3)! Then again it is surely also quite significant that I only found close matches (>20 cM) among people of presumably Akan (Fante) descent. One of them also actually showing the highest amount of shared DNA in my entire African survey (26 cM)! Akan predominance among Gold Coast captives was possibly less pronounced than Igbo predominance has been among Bight of Biafra captives. But still it is undeniable also from my DNA matches survey that very significant ancestral connections do exist between the Akan people and Jamaicans! See also:
- “Ivory Coast/Ghana” also describes Liberian DNA
- West African AncestryDNA results (incl. Ghana, Ivory Coast and Liberia)
Map 3.1 (click to enlarge)
The high level of “Benin/Togo” among Jamaicans and other Afro-Diasporans caused a great deal of confusion for many people. My African AncestryDNA survey findings have demonstrated that this region was often actually suggestive of either southern Nigerian DNA or also Ghanaian DNA. In section 2 I have already discussed how this ambivalence has caused a negative correlation between “Benin/Togo” and associated DNA matches (see also footnote 7). Suggestive that this region was greatly overlapping. More so than any other region within AncestryDNA’s African breakdown (2013-2018 version).
“Benin/Togo” was reported in predominant amounts in particular among Ewe testers from southeastern Ghana. Although certainly not exclusive to them! Not surprising given that the Ewe are also to be found in neighbouring Togo. Where they are the biggest ethnic group. Plus the Ewe are part of the Gbe language family which also includes for example the Fon from Benin. Going by historical plausibility Jamaicans can actually also expect to have a considerable degree of genuine Beninese and/or Togolese ancestry (non-Ewe). But usually this will be traced back further in time. For more discussion:
- Akan or Ewe? West African AncestryDNA results 2013-2018
- “Benin/Togo” also describes DNA from Ghana & Nigeria
From table 3.5 it can be confirmed that Ewe matches were quite common among my Jamaican survey participants! Even more so when combined with most likely Togolese or Beninese matches. Only three people did not receive any Ewe or Benin/Togo matches (see this spreadsheet). This outcome surely must account for at least a significant part of the associated “Benin/Togo” scores observed among Jamaicans. Although the Ewe live in a relatively small area of Ghana (see this map) they are still about 14% of the total population (Akan are about 48% according to estimates).
Going by average shared DNA etc. the Ewe matches I found do not differ that much from the Akan matches. Although I did not manage to find any close Ewe matches (>20 cM) still 9 matches were greater than 10 cM. However the most likely Beninese and Togolese matches showed a clearly lower average amount of shared DNA (~7cM). And also the share of small matches was rather high (60%). I was actually pleasantly surprised by the still considerably high number (20) which showed up. Given that migrants from Togo and especially Benin are quite uncommon in the USA (see chart 1.1). Fortunately through the laudable efforts of the African Royal DNA project several persons still living in Benin have actually also been tested by now!
I suppose the weaker matching strength for Beninese and Togolese matches might imply that many of them might be either population matches or even false positives. Still given the historical context I do also strongly suspect that a genealogical timeframe is still plausible in many cases as well. It is after all known that captives from Benin and Togo, the so-called Bight of Benin, arrived in Jamaica mostly in the late 1600’s and early 1700’s (see this table). These people were then commonly referred to as either “Popo” or “Wyddah” (various spelling).
Given my lack of knowledge in Ghanaian surnames (beyond Akan & Ewe surnames) I was not always able to identify a plausible ethnic background. Therefore 69 Ghanaian DNA matches were left unspecified. In the total overview the number of for example 4 Ga-Adangbe matches might seem a bit subdued. But I suspect several more are among the unspecified matches. I have already discussed how overall speaking Nigerian DNA matches turned out to be more numerous than Ghanaian ones. However one must be careful not to generalize too much. Because actually I also found that matches from Ghana and Benin/Togo combined were relatively more frequent for a sub-group of my survey participants. I will discuss this finding in greater detail in section 6 below.
4) Central & Southeast African matches
Table 4.1 (click to enlarge)
The number of Central & Southeast African matches (39) in my survey is quite low when compared with the number of West African matches (795). They form about 5% of the total (39/861), which seems in contradiction with actual ancestral proportions. Going by regional admixture a larger share might have been expected. In my survey of 100 Jamaican AncestryDNA results I calculated a Central & Southeast African share of 21% within the scaled African breakdown (see table 3.2). Based primarily on the group averages for “Cameroon/Congo” (17%) but also in addition “Southeastern Bantu” (3%). Such a proportion (15-20%) also agreeing with historical evidence and other clues (see section 1 of this blogpost).
A skewed database effect is probably again the main explanation. As Central African migrants are not very common in the USA. Which decreases the odds of getting matched with them. Especially when compared with much more numerous Nigerian & Ghanaian migrants (see chart 1.1). Still useful to see that matches from Cameroon and the Congo (DRC & RC) were clearly most frequent. And also with more robust amounts of shared DNA. Notice the average being around 8 cM! Similar to most of the West African matches. The one single match from São Tomé & Principe (confirmed!) also showing a rather high shared amount of >10 cM. This island’s African origins are actually quite wide ranging. Mainly from around the Gulf of Guinea but also extending into Mozambique and Cape Verde! Therefore several other ancestral scenarios might apply. But quite likely this match is due to a shared Central African ancestor.
Very interesting that the number of Congolese and Cameroonian matches should be about equal (11-12). Also in other regards their matching strength seems similar. As mentioned previously a good part of the Jamaican “Cameroon/Congo” scores might be reflecting DNA from Cameroon & eastern Nigeria rather than reflecting Congolese ancestry. In contrast with many other parts of the Afro-Diaspora! More data is needed but it might be very telling to see how the ratio of Cameroon versus Congolese matches turns out for other parts of the Afro-Diaspora. To be sure Congolese ancestry is much more widely known and documented within Jamaica though. Even when I suspect that among especially so-called “Moco” captives also an unknown number of people from currentday Cameroonian territory might have been included. Further reading:
- “Cameroon/Congo” = moreso Angola/Congo for Diasporans?
- Genetic importance of Cameroon in DNA testing for Diasporans has been overstated?
- Central Africa in the Caribbean: Transcending Time, Transforming Cultures (M. Warner-Lewis, 2003)
“Southeastern Bantu” was usually a misnomer
Table 4.2 (click to enlarge)
It is of course interesting to also see several Southeast African countries being mentioned in Table 4.1. However one must be aware that these smaller matches (almost all of them <7 cM) are usually false positives (IBS) or population matches (IBP) (see section 1 or also this chart). They are not likely to be traced back to mutual ancestors from the last 500 years or so! Rather I suspect that especially matches from Malawi, Zimbabwe and South Africa are merely due to shared generic Bantu lineage. The so-called Bantu expansion from a few millennia ago is known to have caused a major genetic impact across Central & Southern Africa. And actually also afterwards many wideranging migrations occurred. Furthermore one must take into account that due to greater migrant presence in the USA and also the UK the odds of matching with in particular South Africans and Zimbabweans are usually greater than matching with historically much more relevant Angolans or Congolese. See also:
The two matches from Zambia might possibly still be genuine I suppose. As after all Zambia is a neighbouring country to DRC Congo and Angola. And border crossing migrations also in relatively recent times would have been frequent. Plus it is actually known that Trans-Atlantic slavery also reached into Zambia via the Luba-Lunda empires. The match from Madagascar however presents the most intriguing and convincing case for historical validation. Contemporary reports mention that Jamaican Maroons at first also included Malagasy persons! Documented slave voyages from Southeast Africa into Jamaica have been very rare: 0.1% of the total (see this table). However all 7 recorded voyages were coming from Madagascar! In a rather distant and restricted time period though (1671-1719). Which should result in a great degree of dilution. Still very fascinating that at least one Madagascar match showed up in this survey.11 Mirroring the one single Madagascar Runaway Slave being mentioned in table 4.2. See also:
- Central African Maps, incl. historical ones from Zambia
- Southeast African Maps, incl. slave trade statistics
- Overview of all 7 Slave Voyages from Southeast Africa into Jamaica (TAST)
In previous blog posts I have admonished several times that despite the labeling “Southeastern Bantu” was usually indicating southwestern Bantu lineage. At least for Trans-Atlantic Afro-descendants. This should be true for Jamaicans more so than anyone else. Because of the very rare documented slave trade with southeast Africa! Which again was only 0.1% of the total (see this table). It is surely no coincidence that in section 2 I found that “Southeastern Bantu” had the second-worst correlation with associated DNA matches (0.07, see table 2.1). Most likely due to overlap with “Cameroon/Congo”. This latter region’s correlation was better but still only moderate (0.24, see table 2.1). Probably because of overlap with southeast Nigerian DNA and therefore also associated DNA matches.
Actually the average “Southeastern Bantu” score for Jamaicans was generally speaking quite low (around 3%) and therefore in line with historical expectations. Still there were a few outliers as well. I find it quite telling that my survey participant (JAM06) who showed the highest amount for “Southeastern Bantu” (18%) did not receive any Southeast African matches! But in fact he did receive the highest number of Central African matches (5x, both from Cameroon and DRC Congo). Also the average shared amount of DNA for these matches (10 cM) was highest for him (see this sheet). Of course this might simply be a reflection again of Ancestry’s limited customer database. Still this makes for an outstanding outcome in my survey. And therefore provides a very useful clue into his Central African lineage which I suspect was most likely indicated by the combined amount of “Cameroon/Congo” + “Southeastern Bantu”! 12 Further reading:
5) Other African matches
Table 5.1 (click to enlarge)
The 12 remaining African matches (incl. 1 Afro-Arab) I was able to find for my Jamaican survey participants are featured in full detail in table 5.1. This type of African matches was least common, around 1% (12/861) of the total. Not surprising given that they fall outside of the historically plausible areas of West & Central Africa for Jamaicans. Usually reported with small amounts of shared DNA. Increasing the odds of either being false positives (IBC) or population matches (IBP) (see section 1 or also this chart). The share of matches smaller than 7 cM was 75% (8/12). A couple of bigger matches were still also being reported. Do notice however that none of them were greater than 10cM!13
I suppose two opposing views may exist in regards to African matches. Either one believes all of them are the “real deal” and therefore IBD.14 To be fully embraced from the moment of discovery. But other people may be more cautious and assume African matches are possibly false positives or population matches until proven otherwise. These are rather extreme positions of course. And it is important to stay open-minded. But it seems to me that especially in the absence of a historically plausible context a more conservative approach is called for. Instead of unfounded conjecture.
Understandably the eagerness for African matches among Afro-Diasporans is very high. But I feel it is wise to resist the urge of right away “claiming” the same origins as suggested by the recent background of your more surprising matches. As this could be a form of self-serving confirmation bias. I have already outlined some crucial considerations to be kept in mind in section 1. Still I suppose it is also a matter of personal preference whether to focus on historically plausible matches in line with the majority of your regional African admixture. Or rather to go on a wild goose chase of African matches from more eccentric and unexpected places.
Check shared regional admixture for your North & East African matches
Compare Ethnicity screenshots (rightclick and open in new tab to enlarge)
The screenshots shown directly above are featuring a comparison of regional admixture between my Jamaican survey participants on the left and their 12 North & East African matches on the right. This “compare ethnicity” feature is extremely useful to pinpoint shared regional admixture. Especially given that Ancestry does not offer a chromosome browser nor provides any details about the location of shared DNA segments with your DNA matches. This information can be found in the tab called “ethnicity” when clicking on the profiles of any of your DNA matches. For privacy reasons I have replaced the names of my survey participants with their survey code names. I have left in only the surnames for their matches. As these were usually the main basis (along with regional admixture) for my identification shown below in white.
Ancestry puts the regional admixture shared with your DNA matches on top of the list. And this regional component is also highlighted. The list is not always complete due to people who opted out of the so-called full “Ethnicity Profile Display”. Either way judging from the shared regional admixture scores in all 12 cases it seems likely that the actual shared DNA is from either Central African or Fula/Upper Guinean ancestors. This can be verified from the shared region being only “Mali” in case of the 4 Sudanese matches (actually 2 relatives who both matched two of my survey participants). The same goes for the North African matches (the Egyptian match did show “Nigeria” as additional shared region as well). For the 4 Kenyan and the Afro-Arab matches it was only “Cameroon, Congo and Southern Bantu” which was earmarked as shared region. Although of course I have no certainty a connection with Arab Slave trade as well as Fula and Bantu migrations seems quite likely in these cases. See also:
- Map showing Bantu migrations from DRC Congo into Kenya (A.D. 400 – A.D. 100)
- Maps showing Fula migrations across the Sahel into Sudan
- Sudanese Fulani a.k.a. Fellata (Jamtan)
It is essential to grasp that “Eastern Bantu”, “Northern Africa”, “Middle East”, “Ethiopia & Eritrea” and “Somalia” did NOT show up as shared regional admixture for any of these matches. Pretty much ruling out the possibility of shared North African or Northeast African DNA.15 This serves as a reminder of the considerations I discussed in section 1. These somewhat outlandish matches appear to be the result of unexpected or intricate ways of seemingly being genetically related. Several ancestral scenarios may apply as always. All of which should be critically investigated on a case by case basis. Including reversed gene flow originating from either West or Central Africa into North and/or East Africa.16
To be sure direct ancestral connections beyond West & Central Africa are not entirely impossible for Jamaicans. Ancestral origins from Northeast Africa and also within a genealogically meaningful time frame however seem least likely to be supported by any documented evidence I am aware of. Granted: absence of evidence is not evidence of absence. However historical plausibility does greatly impact probability! Therefore I remain highly sceptical of any supposedly Northeast African DNA results being reported. In regards to both DNA matches as well as admixture. Not only for Jamaicans but also other Trans-Atlantic Afro-Diasporans. To be frank I think the odds of any genuine genetic inheritance from especially Northeast Africa (within a genealogical time frame) are going to be very slim. And currently it is certainly being overstated in DNA testing. Then again in individual cases it is not be ruled out. But solid follow-up research and extra scrutiny is always required to corroborate such findings.17 See also:
6) Substructure resulting in a distinctive mix of African regional origins?
Chart 6.1 (click to enlarge)
- Spreadsheet listing all survey participants, sorted on African admixture
- Spreadsheet with more detailed outcomes of substructure
One of the most fascinating aspects of my AncestryDNA survey among not only Jamaicans but also other parts of the Diaspora has been that so-called substructure was eventually revealed. Genetic substructure is basically referring to subgroups within greater populations. To be defined along geographical, social, cultural, or even “racial” lines. Despite commonalities various localized factors may still have caused differentiation between two or more subgroups within a given population. In particular pointing towards a distinctive mix of African regional origins. Showing overlap to be sure but still recognizable due to deviating proportions.
In my previous survey based on 100 Jamaican AncestryDNA results (section 2) I have already explored this theme for Jamaicans based on regional admixture. In this section I will revisit my earlier findings (see this table) and elaborate based on my additional DNA matches survey. As I believe that such substructure can be relevant and useful for greater understanding of context-dependent African roots. Naturally all the disclaimers which I have discussed already in section 1 still apply. In particular the skewed customer database effect on Ancestry which creates greater odds (all other things being equal) for finding Nigerian matches. I have to also stress that these findings are still very much preliminary! Obviously a much greater sample size would be required for the expected patterns to show up more clearly and also in a more robust manner.18 For quick reference:
- Variation & substructure in African admixture levels among 100 Jamaicans (scroll down to section 2)
- Substructure according to admixture level
- Waves of slave trade into Jamaica from specific regions across time (T. Burnard, 2015)
“test the hypothesis of how early creolization among a sub-segment of Jamaicans might have led to greater retention of African regional roots associated with earlier waves of slave trade. Mainly Gold Coast and Bight of Benin. Or stated in reverse how a relatively high share of African-born ancestors from the late 1700’s/1800’s may have resulted in a larger genetic imprint of African regional roots associated with the last waves of slave trade. Principally Bight of Biafra and Central Africa.” (Fonte Felipe, 2019)
Basically the first type of substructure I will be exploring is based on the amount of total African admixture. And how this will translate into the number of DNA matches from especially Nigeria and Ghana. The full range of African admixture (35% – 100%) more or less represents a continuum within my survey group. In order to make the patterns come out more clearly I am therefore focusing on two subgroups on either side of the spectrum: 9 Jamaican survey participants with African admixture being greater than 90%, and on average 98%. Contrasted against 7 Jamaican survey participants with African admixture being less than 70%, and on average 57%. See also spreadsheets linked above for more details.
In my previous survey findings based on regional admixture I was actually not yet detecting a great deal of pronounced differentiation. However as an important finding I did establish that the proportional share of “Nigeria” is somewhat higher for Jamaicans of nearly pure African descent (total African >90%). And actually also for “Cameroon/Congo”. However the reverse expectation of higher genetic impact from the Gold Coast for the subgroup with total African <70% did not really manifest itself. Because the average level of “Ivory Coast/Ghana” was quite consistent across my entire Jamaican survey group, irrespective of admixture level.
Table 6.1 (click to enlarge)
Basing myself now on my DNA matches survey it seems that my previous research outcomes are mostly being replicated. In particular when it comes to Nigerian DNA matches! The differences again not being very stark but still clearly hinting at some distinction. As a general rule it seems that usually higher amounts of African admixture will also lead to higher numbers of African DNA matches. This was already established in section 2 where I calculated a robust correlation of 0.77 (see table 2.1). This is clearly reflected too in table 6.1 where the subgroup of Jamaicans with a higher degree of African admixture (>90%) is shown to have received 37 African DNA matches on average. Against 19 African DNA matches on average for the other subgroup with a lower degree of African admixture (<70%).
However if you look closely you will see that it is especially the number of Nigerian matches which shows the highest differentiation. For almost everyone in my survey group the number of Nigerian DNA matches has been the greatest. With the number of Ghanaian matches in second place. However proportionally speaking the average frequency of Nigerian matches is higher among subgroup total African > 90%. Out of an average total number of 37 matches 22 were Nigerian (22/37=61%). See also pie-chart 6.1 further above. Persons with a lower degree of total African admixture (<70%) showing a somewhat higher frequency of Ghanaian matches (6/19=31%). However their frequency of Nigerian matches (10/19=51%) is still greater.
Because the average number of other types of matches (esp. from Central Africa and Upper Guinea) was so low (1) it is perhaps not that surprising to also not see that much differentiation among these type of matches. The average shared DNA seems fairly consistent for the most part. But perhaps this is merely due to the small sample size. Given the “creolization hypothesis” I have discussed in my previous blog post you might have assumed that people with a higher degree of African admixture might also have closer matches, on average. But this does not really show up.
Still in one major aspect it is again transpiring that a presumably higher genetic contribution from the Bight of Biafra among one particular subgroup (Jamaicans with total African> 90%) could indeed be valid. To be measured by the proportional share of Nigerian DNA matches (61% versus 51%, see chart 6.1). And this time the reverse expectation of a relatively higher frequency of Ghanaian genetic contribution also seems to be observable among the other subgroup with total African <70%. Again to be measured by the proportional share of Ghanaian DNA matches (31% versus 25%, see chart 6.1). Obviously the differences are not that major and individual variation is not to be denied! As these findings are all based on group averages. And actually for one survey participant (JAM08) with total African admixture being 99%, the number of Ghanaian DNA matches (15) was greater than the number of his Nigerian matches (14).
“Northern Afro-Jamaicans” versus “South-Central Afro-Jamaicans”
Map 6.1 (click to enlarge)
As an alternative way of looking into substructure for my Jamaican survey group I have also taken into consideration their assignment into Ancestry’s so-called genetic communities. Sometimes also referred to as “migrations”. This community feature has been integrated within Ancestry’s Ethnicity Estimates since 2017. It is based on having a strong genetic connection (measured by IBD matches above a given threshold, possibly >12 cM) to a certain group of people. These genetic clusters or networks of interrelated people are given greater context by way of their average admixture scores, family trees and implied migration histories. Even when it does have its shortcomings I do find that Ancestry’s genetic community tool is reasonably predictive and quite useful! It provides a great way to sort out your Jamaican related DNA matches. Although many of these matches might actually be of mixed descent. Furthermore not all of your Jamaican related matches might be covered. For more details see also:
- Help & Tips in regards to Ancestry’s migration/genetic community tool (Ancestry)
- Genetic Communities™ White Paper (Ancestry)
- Clustering of 770,000 genomes reveals post-colonial population structure of North America (Nature, 2017)
Naturally there are many disclaimers to be kept in mind. You should not expect any exact delineation! Especially given the great deal of internal migration within Jamaica. But just taken as rough proxies of genetic differentiation these communities are quite useful for my research purposes. Based on the maps shown above and also my own observations the “South-Central” community is more restricted in scope. Being mostly based on shared ancestry from St. Elizabeth. And also to some degree Clarendon (see my spreadsheet). Regrettably the “Northern” community covers almost all of the rest of Jamaica. Hopefully in the near future Ancestry will be able to at least distinguish the Northwest from the East. But as it is, actually this genetic community is already distinctive in its own right.
Chart 6.2 (click to enlarge)
Table 6.2 (click to enlarge)
Looking into my research findings above one must keep in mind that the same principle of higher African admixture leads to a higher number of African matches is still at work. Because the average level of African admixture for the “Northern Afro-Jamaicans” sub-group is 85%. While for the “South-Central” sub-group it is 70% (see also this spreadsheet). It is also noteworthy that in my former comparison all the survey participants with African > 90% were actually “Northern Afro-Jamaicans”! While it was more balanced for the subgroup < 70% African (see this spreadsheet). So therefore there seems to be some overlap in causation. However going by the greater differentiation on display in chart 6.2 and also the greater sample size it seems likely to me that an extra factor is involved. Most likely to do with geography. But also possibly due to earlier onset or more widespread creolization in St. Elizabeth? Locally-born Afro-descendants (whether Mixed or Black, enslaved or freed) representing a greater proportion of total parish population during the 1700’s & 1800’s than in most other parishes in Jamaica?
I should repeat that my “creolization hypothesis” is clearly based on a great deal of generalization. While reality is much more complex. All depending on individual genealogy!19 However it seems meaningful that again a considerable gap in number of Nigerian matches (19 versus 12) is combined with an equal number of Ghanaian matches (7) and even a slightly higher average number of Benin/Togo/Ewe matches (3 versus 2) for the “South-Central” subgroup! And in fact also for Upper Guinean matches (2 versus 1). The last two findings being noteworthy given the known earlier waves of slave trade from the Bight of Benin as well as Upper Guinea (1676-1725, see this table). In my earlier regional admixture findings I did already find a somewhat elevated “Benin/Togo” group average (20.2% vs. 18.6%) for my Jamaican survey participants with total African <70%.
Naturally a much more solid basis needs to be achieved for these preliminary findings. Although intuitively they do seem to be suggestive of meaningful substructure. Another factor to be kept in mind is that apparently St. Elizabeth has a reputation of being one of the most “mixed” parishes in Jamaica. This might be based mostly on anecdotal evidence. However for what it’s worth (sample size n=11 is minimal!) I did also observe a greater degree of non-African admixture (30% on average) among my “South-Central” subgroup. And intriguingly this reputation of greater diversity is also reflected in their more balanced composition of African DNA matches (see chart 6.2)! Again more research is needed. Personally I am also fascinated by the implications of the share of African-born slaves being reported for Jamaica circa 1817-1820. The relatively low share for the abolished Vere parish possibly being a proxy for St. Elizabeth and Clarendon? See also:
- St. Elizabeth history (St. Elizabeth Municipal Corporation)
- The Parish of St. Elizabeth Jamaica (Jamaica Global)
- Percentage of African-born slaves, 1817-1820 (B.W. Higman, 1976)
Substructure based on parish level?
Map 6.2 (click to enlarge)
Table 6.3 (click to enlarge)
Another type of substructure which seems like a promising field of research is based on parish or also county origins. Jamaica is relatively small and a great deal of internal migration across the island must have taken place across the generations. But still it might be that similar to the USA, Brazil and Haiti certain rural parts of the country do carry a greater genetic imprint from certain African regions due to local differences in slave trade. Or also the clustered arrival of African contract labourers.
However due to the limitations of my survey group I have not been able to research this in a meaningful manner yet.20 Although I suppose my previous discussion based on substructure according to genetic communities is already a step towards that direction. Either way I do strongly believe that paying close attention to localized context may benefit one’s research into specific African lineage. Fortunately many such clues are available for Jamaica.
A greatly significant hint might be derived from the very high share of Bight of Biafra in slave trade to Montego Bay. As can be seen in table 6.3. Montego Bay is located in Saint James parish in the northwest. Which is at some distance from Kingston on the southeast side of the island. The greater part of slave trade for Jamaica was actually handled through Kingston. With captives subsequently being transferred to other parts of the island. But perhaps due to relative isolation this circumstance might still have important ancestral implications for Jamaicans from the northwest and apparently also St. Ann. See also:
- Igbo people in Jamaica (Wikipedia)
Below I will just briefly list some of the more striking outcomes in my survey and how they might possibly correlate with parish origins. As far as I am aware none of my survey participants had exclusive family ties with St. James. Looking into people with an above average number of Nigerian DNA matches does not yet reveal anything noteworthy yet. Except that almost all of them are as expected part of the “Northern Afro-Jamaican” community. Unfortunately I have not (yet) been informed about the parish origins of my survey participant JAM02. He received by far the highest number of Nigerian matches (43, see this spreadsheet). The 3 people who had more Yoruba than Igbo matches (JAM08, JAM12 and JAM19) did not mention any family ties with Westmoreland or Hanover. These being the main parishes associated with Yoruba contract labourers.
Moving on to survey participants with an above average number of Ghanaian matches (see this spreadsheet). Again not really a clear pattern arising. As in fact these persons were from several parts of the island. Including this time also many people from the “South-Central” community. The highest number of Ghanaian matches (15) being obtained by JAM08 who has parish origins from the east (Portland, St. Thomas). He also had the second highest score for “Ivory Coast/Ghana” (50%). The highest “Ivory Coast/Ghana” score (63%) was obtained by survey participant JAM15 and she also has parish origins from the east: St. Thomas on both sides. Interestingly she combined 7 Ghanaian with three Liberian matches and even one from Ivory Coast!
Too few DNA matches were detected from other areas in Africa to make any meaningful inferences yet. However still interesting that the highest number of Central African matches was obtained for someone from Manchester (JAM06, see this spreadsheet). And in fact also with the highest average shared DNA amount (10 cM). Suggestive of relatively recent ancestry (late 1700’s, early 1800’s?). Manchester being a parish known to have expanded its sugar and coffee plantations also during later time periods. Necessitating continued slave imports. In contrast with more “mature” parishes. For that reason Manchester is also known to have had a higher percentage of African-born slaves in the early 1800’s. Perhaps telling therefore that this person did not get assigned to “South-Central” but still ended up in “Northern”. Even when Manchester is right next to St. Elizabeth. See also:
7) South Asian and Jewish matches
Table 7.1 (click to enlarge)
In this survey I have also included South Asian & Jewish matches. Mainly in order to investigate how even small amounts of regional admixture may result in associated DNA matches. This turned out to be the case indeed! When comparing with the African matches the skewed database effect on Ancestry is clearly demonstrated. Yet again a reaffirmation that finding DNA matches associated with a certain part of your ancestry will be dependent on the ethnic composition of the customer database.
As after all my survey group and also Jamaicans in general are predominantly of African descent (~80%). While South Asian and especially Jewish lineage is very minor on average (resp. 1.1% & 0.2%, see table 1). Still because of a structural under-representation of African DNA testers on Ancestry the number of especially Jewish matches (1477) was overwhelming and disproportionate to actual ancestral contribution (0.2%). While the South Asian matches proved to be of much greater genealogical use because of bigger size.
I will start my discussion with the 33 South Asian DNA matches I found for 4 of my survey participants. In other words 26 persons did not receive any South Asian DNA matches! Which makes sense as most of these persons actually also did not show any South Asian admixture to begin with. Or only unreliable trace amounts (<1%) during the 2013-2018 version.21 In my previous blog post (section 4) I already described how South Asian admixture is usually quite diluted among Jamaicans. And often also in line with the expected genetic inheritance of one single South Asian grandparent (~25%), great-grandparent (12-13%), great-great grandparent (5-6%) or even great-great-great grandparent (2-3%) (see this table). Very useful also for visualizing dilution of DNA inherited from single African ancestors. More likely to be from the 1700’s then. Instead of the mid-1800’s as is the case of South Asian ancestors for Jamaicans.
The total number of South Asian DNA matches (33) I found during my survey is rather small. In particular when compared with the number of Jewish matches (1477). I suppose this indicates that people of fully South Asian descent are also quite under-represented in Ancestry’s customer database. Still there are already pretty good odds of corroborating even a small degree of South Asian lineage! At least judging from this survey. Keeping in mind also the very high correlation I found between South Asian admixture and associated DNA matches (0.99, see table 2.1). During my previous survey among 50 Cape Verdeans I looked specifically for South Asian matches as well. Also with some success but more so on a hit and miss basis (see this table).
One person (JAM03) in my survey group clearly stands out with 28% South Asian admixture. And accordingly he also received the greatest number of South Asian matches (23). A fascinating outcome was obtained for my survey participant JAM07. Although he only shows 4% South Asian admixture I still managed to find the biggest DNA match within my entire survey (109 cM). JAM07 was already aware of having a mixed race family line, prior to DNA testing. But he did not know it was in fact a distant South Asian connection. This finding can therefore be a tremendous help in tracing back to his actual South Asian ancestor! Of course he was already alerted of the possibility of distant South Asian lineage by way of his admixture results. Helping him to see things in proper proportions.
Judging from the high shared DNA amount this match is bound to be a very close relative and probably an Indo-Jamaican. But possibly also from Guyana or Trinidad. Luckily a few of the other closest South Asian DNA matches turned out to have a public family tree. From which I could confirm that they were born in Jamaica. And one of them actually also mentioned a more distant ancestor from Bihar state in India! In almost all cases the relevant ancestral scenario will involve Indian contract labourers from the 1800’s. However in a few cases I suppose also other ancestral options might apply. Apparently the presence of East Indian persons in Jamaica has already been recorded in the late 1700’s! Just speculating but I suppose also a few Indian sailors (Lascar) may have ended up in the West Indies? See also:
- Indian Jamaica Genealogy (Facebook)
- East Indian & Chinese men mentioned in St. James census of 1774 (Jamaican Family Search)
- Malachi Kirby [20% South Asian]: ‘Playing Kunta Kinte in Roots reboot allowed me to find my own roots’ (Evening Standard, 2017)
- Know Your Roots: LeVar Burton & Malachi Kirby [20% South Asian]| History (Youtube, 2016)
Ashkenazi or Sephardi?
Map 7.1 (click to enlarge)
My survey findings in regards to Jewish DNA matches are evocative in several aspects. Most importantly perhaps they seem to highlight that trace amounts of admixture can be indicative of distinctive lineage. In my opinion dismissing small amounts of admixture as “noise” beforehand is not conducive to an open minded research strategy. Close scrutiny and independent verification are naturally always called for. However each case is to be judged on it own merits. Otherwise you run the risk of loosing out on potentially very useful discoveries about your ancestry!
Nonetheless as stated before the ethnic composition of Ancestry’s customer database did impact my findings a great deal. In this case it is quite obvious that due to a huge number of American Jewish customers on Ancestry you are almost guaranteed of getting matched with any degree and any kind of Jewish lineage. More particularly Ashkenazi Jewish DNA matches will usually be showing up. Regardless if your Jewish ancestry would actually be mostly Sephardi or even also Mizrahi. Amazingly even if your Jewish admixture is smaller than 1%!
Jewish endogamy does also play a big role though. Jewish genetics being well known for this complicating factor in one’s genealogical research. As it implies a lot of matches will probably be false positives or population matches! Especially when dealing with smaller matches (<7cM). The share of these matches in my survey being almost half of the total (633/1477=43%, see table 7.1) But confusingly also if these matches are relatively big (>10 cM)! Plenty scientific studies have been published on the distinctiveness of Jewish genetics. When researching Jewish lineage it is well recommended to get acquainted with at least some of them:
In my previous blog post (section 3) I already described how usually only trace amounts of around 1% “European Jewish” are being reported for Jamaicans. However for a greater majority it does not get detected at all! In my current survey group (n=30) the maximum score for “European Jewish” was a mere 2%. Still with only this small amount of Jewish admixture I was able to find no less than 915 Jewish matches for my survey participant JAM29! Overwhelmingly Ashkenazi persons, it seems. This was the case for JAM01 & JAM19 as well and they also received 100+ Jewish matches. The remaining 7 persons with Jewish matches were more often given presumably Sephardi matches. But in markedly lower total numbers (<55).22
The “European Jewish” region is in fact first most describing genetic similarity with Ashkenazi Jews. But based on my observation it seems that Sephardi DNA is described on AncestryDNA more so by a combination of “Italy”, “Middle East”, “Turkey & the Caucasus” and often to a lesser degree also “European Jewish”. This is a crucial issue as Jamaica’s Jewish heritage is said to be mostly linked with Portuguese Jews, a.k.a. Sephardi Jews. But not exclusively so! Because the presence of Ashkenazi Jews in Jamaica has actually also been recorded rather early in history already. With an English-German synagogue apparently built in 1787. Also a few Mizrahi Jews would actually have been present in Jamaica. Arriving from Syria and Egypt from the late 1800’s onwards. See also:
- History of the Jews in Jamaica (Wikipedia)
- Jews in Jamaica (Museum of The Jewish People at Beit Hatfutsot)
Still from reviewing table 7.1 you might have gotten the wrong impression. As no less than 92% (1372/1477) of all Jewish matches were quite likely Ashkenazi. I should repeat that making the distinction between Ashkenazi and Sephardi matches was done on a best effort basis. Mostly going by regional admixture and surnames (see section 8). Actually the number of presumably Sephardi matches (87) was still good and also quite informative. But due to unequal customer representation in Ancestry’s database the odds of finding Ashkenazi matches are just that much greater. After all American Jews are for the greater part (more than 90% even?) Ashkenazi from originally Eastern Europe. Unless you want to jump to misleading conclusions you are well advised to keep this skewed database effect in mind.
It is interesting to also compare with my earlier Cape Verdean survey findings from 2018 (see this blogpost). In which I also singled out Jewish matches. On average I then found 30 Jewish matches per survey participant. Based on only 0.4% Jewish admixture (see this table). Which compares well enough with the 49 Jewish matches on average during this Jamaican survey. Based on only 0.2% Jewish admixture (see table 1). Especially given the astounding fact that Ancestry’s customer database grew with about 5 million during this interval!
I then also made a provisional distinction between Ashkenazi and Sephardi origins. For Cape Verde the historical context is even more so in favour of practically exclusive Sephardi lineage. However it turned out that due to the skewed customer database effect it was still Ashkenazi matches which were more numerous. Albeit in much more balanced proportions than for Jamaicans. It was also quite telling that the closest matches were still Sephardi. Furthermore the average shared amount of DNA was somewhat higher among them than among Ashkenazi matches.
These very same patterns in fact also show up during this Jamaican survey as can be seen in table 7.1! The two closest Jewish matches were most likely at least partially Sephardi Jamaican. These were both reported for my survey participant JAM13. Who actually did not show up with any “European Jewish” admixture! But instead she did obtain 1% “Middle East” in Ancestry’s 2013-2018 version and 1% “Iran/Persia” after the 2019 update (see this screenshot). Very useful to know that such admixture is therefore most likely also to be connected with Sephardi lineage!23
Amazingly the second-highest Jewish match (21 cM) has an extensive public family tree from which it can actually be verified that his family has a very long history in Jamaica. Going back to one Jamaican-born ancestor with a Portuguese surname from 1730! And tracing back even further he also lists a Portuguese-born ancestor from the 1600’s! He does also have partial Ashkenazi lineage though. But again Jamaican-born since atleast the mid 1800’s! No such details regrettably for the closest match (31 cM). However very interestingly he does share the “Afro-Jamaican” community with JAM13 (see this screenshot). Even when he does not have any African DNA (according to Ancestry)! Further reading:
- Jamaican Jewish Records (Jamaican Family Search )
- Isaac Mendes Belisario, Jamaican artist in 1800’s (That’s Inked Up, 2013)
- Sean Paul: a Yiddisher Rasta man (Ynet News, 2007)
Figure 8.1 (click to enlarge)
While analyzing the DNA matches of my Jamaican survey participants I have always taken a cautious research approach when deciding on their most likely background. Going by any clues given but in particular:
- plausible regional admixture
- plausible surnames
Whenever available I also took into consideration actual birth locations and other relevant profile details. Unfortunately such information was usually not provided. Because most people on Ancestry do not tend to have public family trees. In this section I will describe the methodology I applied in more detail. But first of all I would like to repeat that my categorization of African DNA matches is not intended to be waterproof.
The same goes for the distinction being made between presumably Ashkenazi & Sephardi matches in section 7. Obviously I did not have perfect and complete information at hand for each single DNA match. Instead of aiming for 100% accuracy I therefore processed the data on a best effort basis to get a general idea. In order to avoid any false assignment I actually preferred to leave out several potential African matches from this survey whenever I was in doubt.
Finding African DNA matches can often seem like a daunting task. Almost like finding a needle in a haystack. However the filtering method I blogged about in 2017 already makes it quite easy and time-saving to single out distinctive ethnic profiles. Because my Jamaican survey participants kindly agreed to share their Ancestry profiles with me I was able to zoom into their most likely African DNA matches. By first scanning all DNA matches with DNAGedcom and then filtering in Excel for profiles containing only African or compatible ethnic regions (“Middle East” etc.). This gave me an initial overview of potentially African DNA matches which however needed to be analyzed further to remove Afro-Diasporan profiles.
The South Asian and Jewish DNA matches, whenever available, were obtained by sorting on region and text filtering. For each of my 30 survey participants I generated an Excel file featuring all of their DNA matches. As well as their filtered African, Asian and Jewish matches in separate tabs. Finally all of this data was then combined for statistical analysis in my online spreadsheet. All calculations mentioned throughout this sheet and especially in the tabs “Main Overview”, “African Overview” and “SS Overview” can be verified independently by viewing the applied formula in the function bar (fx) in the upper left corner.
For my step-by-step tutorial on how to detect African DNA matches see:
- How to find those elusive African DNA matches on Ancestry (2017)
- Advanced Excel Filter Settings (link to my googlesheet containing the filter criteria I applied)
- DNAGedcom Client (software I used for scanning all of the DNA matches of my survey participants)
When in need of assistance see also:
Plausible regional admixture
Figure 8.2 (click to enlarge)
Figure 8.3 (click to enlarge)
Regional admixture is one of the two key pillars in my analysis of African as well as South Asian and Jewish DNA matches. In particular the African breakdown as it is being reported by AncestryDNA after the recent 2019 update. Although actually also the previous versions still proved to be relevant. Ancestry used to provide a summary of the ethnic regions for each DNA match on their profile page. Although no longer visible now these details are still being scanned by DNAGedcom. Which makes it possible for me to still apply my filtering method (see column D in figure 8.1). Because I started this survey in September 2019 most of the regional summaries are still reflecting Ancestry’s flawed update from 2018.24
Ancestry’s compare ethnicity tool (see figure 8.3) has also been indispensable in my efforts to identify plausible backgrounds for the filtered matches. Allowing me to verify the exact regional admixture scores of the African DNA matches I had sorted out beforehand! This is something I have checked for each separate African as well as each South Asian match contained in this survey. To decrease the odds of misidentification. Because of the overwhelming number of Jewish matches I only checked their profiles at random. Paying closer attention to possibly Sephardi profiles.
In previous blog posts I have demonstrated how regional admixture CAN be indicative of distinctive lineage. This goes not only for African DNA but also European and Asian DNA in fact. Despite inevitable overlap regional a.k.a. sub-continental admixture is certainly not meaningless or totally random as is sometimes assumed. Some regions on the far end of the spectrum may even be said to be almost mutually exclusive. Such as “Senegal” and “Cameroon, Congo & Southern Bantu” being proxies for resp. Upper Guinean and Central African lineage. South Asian DNA can quite accurately be distinguished from other types of Asian DNA, such as Chinese. Also Jewish admixture can usually be reliably detected, even at very subdued level.
Going by my observations over the years Ancestry’s 2013-2018 version has been 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. Regrettably subsequent updates in 2018 and 2019 have complicated a straightforward interpretation afterwards. For more details see also:
- African AncestryDNA results (2013-2018 version) (full overview)
- Ancestry’s 2019 Update: Back on Track Again?
In this current endeavor of analyzing the African DNA matches for my Jamaican survey participants these regional admixture patterns turned out to be particularly helpful to establish a plausible background within Africa. Obviously not pinpointing anything precise but already zooming into specific areas, countries or even ethnic groups at times. I mostly relied on the following decision rules:
- Nigerian matches: “Nigeria” clearly predominant. Additional minor “Cameroon, Congo, Southern Bantu” or “Benin/Togo” scores being used to establish the likelihood of either Igbo or Yoruba matches. In combination also with plausible surnames. Because of DNAGedcom’s scanning I was also often given the old summary of ethnic regions (see column D in figure 8.1). Which I interpreted according to my knowledge of either the updated 2018 version or the initial 2013-2018 version.24
- Ghanaian matches: combination of “Ghana”, “Mali”, “Benin/Togo and “Nigeria”. Slightly tending towards “Ghana” for Akan matches. More so tending towards “Mali” and “Benin/Togo” for Northern Ghanaian matches. To be combined with plausible surnames. Because of DNAGedcom’s scanning I was also often given the old summary of ethnic regions (see column D in figure 8.1). Which usually was much easier to interpret.
- Benin, Togo & Ewe matches: Predominant “Benin/Togo” scores in combination also with “Nigeria” and “Ghana”. To be corroborated by plausible surnames.
- Liberian & Sierra Leonean matches: Predominant “Mali” scores. For Liberians at times combined with minor “Ghana” or even “Benin/Togo ” scores. Because of DNAGedcom’s scanning I was also often given the old summary of ethnic regions (see column D in figure 8.1). Which I interpreted according to my knowledge about either the updated 2018 version or the initial 2013-2018 version.
- Upper Guinean matches: “Senegal” and/or “Mali” clearly primary and predominant. “Africa North” and/or “Middle East” only showing up above trace level for most likely Fula matches. To be combined with plausible surnames. Whenever the main regional combination as displayed by DNAGedcom also included “Ivory Coast/Ghana” as main region aside from “Senegal” and/or “Mali” I tried looking for other clues (esp. surnames) to make a Sierra Leonean or Guinean background more plausible.
- Central African matches: predominant scores (>90%) for “Cameroon, Congo & Southern Bantu”. To be combined with plausible surnames.
- Southeast African matches: predominant scores for “Cameroon, Congo & Southern Bantu”. But also “Eastern Bantu” showing up to a considerable degree. To be combined with plausible surnames.
- North African matches: predominant scores for “Northern Africa”. Minor scores for “Portugal” as well as “Middle East” in line of expectations due to genetic overlap. Also usually minor West African regional admixture showing up. Consulting the compare ethnicity tool made it easier to establish the shared regional component.
- East African matches: substantial scores for either “Eastern Bantu”, “Hunter-Gatherer”, “Ethiopia & Eritrea” or “Somalia”. Often still also combined with “Cameroon, Congo & Southern Bantu”. Consulting the compare ethnicity tool made it easier to establish the shared regional component.
- South Asian matches: combination of “Southern & Eastern India” and “Northern & Western India” adding up to (nearly) 100%. Only minor trace regions from elsewhere in Asia allowed. Otherwise not taken into further consideration. To be combined with plausible surnames. But not really a precondition.
- Jewish matches: “European Jewish” being the single main region for most likely Ashkenazi matches. Only minor trace regions from Europe and West Asia allowed. I checked such profiles at random and they usually turned out to show 100% “European Jewish”, or nearly so. Whenever I saw a more increased level of West European DNA I left them out of my survey. To rule out alternative ancestral connections. For possibly Sephardi profiles I looked into combinations of “European Jewish” with other main regions such as “Middle East”, “Italy”, “Turkey & the Caucasus”. I did not make any attempt to single out Mizrahi matches. Therefore some matches grouped under Sephardi might very well actually be Mizrahi or mixed between the both! Naturally many Sephardi matches might still be partially Ashkenazi as well. Additionally I also looked into plausible Sephardi surnames. But not too strictly. More weight being given to the regional admixture outcomes. When wanting to perform such an analysis in a more thorough manner it is however very useful that Sephardic surnames tend to be quite distinctive. See also:
Plausible African surnames
Figure 8.4 (click to enlarge)
- Overview of all African DNA matches (incl. surnames in column C)
Regional admixture provided the first step in my identification of a plausible background for African DNA matches. However I nearly always continued my plausibility check by also focusing on African surnames (and at times also African first names). In fact I have tended to exclude possibly African matches from my survey out of precaution. Whenever they did not feature an African surname on their profile page. Unless any other corroborating evidence was to be found.
For each possibly African surname, first name or even nickname I have performed a search on not only Google but also Facebook to find out more details. The forebears.io website has been a particularly helpful resource in my efforts (see figure 8.4). As it provides solid statistics for surname incidence and frequency. Often enabling me to zoom into most likely nationality or even ethnic group. Although many African surnames are in fact widespread across several countries. Especially Muslim names tend to be quite generic.
Furthermore of course also ethnic-specific surnames are often only reflecting one single family line on either the paternal or maternal side. Inter-ethnic unions are never to be ruled out however! Both recently or further down the line. Also one needs to be careful because sometimes Afro-Diasporans adopt African names (due to conversion to Islam, marriage or as an Afro-Pride statement). There is also the issue of different spelling variations. Which can however also be used advantageously when the same name has an English, French or even Portuguese variant. But sometimes seemingly similar surnames will be used in various countries for unrelated reasons but sheer coincidence. Naturally one needs to be aware of such limitations and not jump to conclusions. Still by combining with regional admixture and other clues the odds of finding a plausible background can often be greatly enhanced!
Throughout my various research projects I have always made great efforts to safeguard the privacy of my survey participants. Leaving out any name details, except for acronyms when approval was given. As in fact I have also done this time for my Jamaican survey participants who are only identifiable by JAM01, JAM02 etc.. However in regards to their African DNA matches I have decided to include their surnames in my spreadsheet. As I believe these African surnames can have great educational purpose. In order to prevent full identification I have still not displayed their full names. If anyone recognizes themselves in these matches and should not be be comfortable with this display please send me a PM and I will act accordingly. Some useful resources in regards to African surnames:
- Forebears.io (surname search)
- Igbo surnames & meanings (Okwu ID)
- Yoruba surnames (Yorubaname)
- Efik names
- Akan surnames (Wikipedia)
- Ewe surnames (Blakk Pepper)
- Sierra Leone Clan names
- Fula common names (Afropedea)
- Fula surnames (Revolvy)
- Wolof Patronymes (Wikipedia)
- Serer maternal clans (Wikipedia)
- Noms et prénoms du Sénégal (Planète Sénégal)
- Nomes proprios da Guiné-Bissau (CART 3494)
Figure 8.5 (click to enlarge)
I consider the various survey findings I have presented on this page to be the culmination of my efforts across the years to dig into the specific African origins of Jamaicans. Although of course there is plenty room for improvement and follow-up research! One might say these research findings are only skimming the surface given the structural underrepresentation and skewed composition of African customers within Ancestry’s database. Biased somewhat to finding especially Nigerian & Ghanaian matches. However given additional clues which have been explored in previous blogposts, I do not believe my main survey outcomes are just some fluke. Rather I suspect they will be replicated to a large extent in future research efforts when more favourable database conditions will be in place.
As I have maintained from the very start of my blogging “career” in 2014 I am convinced that new insights are often generated by just putting two and two together. In other words I think a multi-disciplinary approach often works better than just limiting yourself to a one-sided view. Combining genealogy not only with various aspects of genetics (admixture analysis, autosomal DNA matches, haplogroups etc.) but also with history, ethnography, linguistics and so forth. Throughout this blog post I have already highlighted several times how correlating (regional) admixture analysis with DNA matches can be rewarding and reinforcing in many cases.
Both aspects of genetic genealogy obviously have their own shortcomings. But admixture results can reveal insightful ancestral connections even when DNA matches are not (yet) available and vice versa. Regional admixture may also enable the identification of a plausible background of ones DNA matches. Your admixture results can be helpful as well to gauge how your DNA matches relate with actual ancestral proportions. While DNA matches may serve to corroborate distinctive ethnic/regional lineage detected by your admixture results. As always it pays to use scrutiny and discretion in stead of jumping to conclusions or putting all your eggs in just one basket!
I have also stated from the beginning that I am a firm believer of democratizing knowledge. Intriguingly several of my Jamaican survey participants received the very same African DNA match. One likely Igbo match was reported for no less than 4 of my 30 survey participants (see Anyagafu in this sheet)! All of them unrelated within the last 2 generations as far as I am aware. I suspect such outcomes may partially be explained by some degree of endogamy among Jamaicans as well as recurring population (IBP) matches. However it may in some cases also be indicative of a mutual African ancestor within a genealogically meaningful timeframe! I imagine most likely from a relatively late time period (1800’s or late 1700’s).
It could be very beneficial therefore to focus on shared African matches as one avenue of promising follow-up research. Using advanced tools such as triangulation or chromosome mapping to identify the associated shared DNA segments may then lead to fitting African DNA matches along specific family lines. Mapping African MRCA’s as far back as possible by looking into shared matches. Exploring how you relate to your African DNA matches may often involve mutual learning and joint-effort research. Such collaborations are not only limited to your direct African connections but also triangulated ones! This type of advanced and innovative research is something I aim to engage with myself in 2020!
The ultimate goal of trying to fit your African matches (MRCA’s) into your family tree will usually be very tricky though given scanty information.25 And it will also require a lot of patience. But it might still be worthwhile for eventually zooming in closer to your African origins along a certain family line or even actually identifying an African ancestor! Breaking down those brick walls based on paper trails!
Having other close relatives also DNA tested will of course be greatly helpful. Especially if they share the same African matches with you. However any shared matches for your African match might do the trick I suppose. As long as you can figure out how these shared matches are to be placed in your family tree. Of course Ancestry is not really helpful in this regard as they do not provide a chromosome browser nor do they provide the location of shared DNA segments. However if any of your African DNA matches is also on Gedmatch, 23andme or MyHeritage you could get things started I guess. Triangulation and DNA Painter seem poised to give you more insight. For more details see:
- Benefits of Triangulation (Segmentology, 2015)
- Using DNA Painter to reconstruct ancestral DNA (Ultimate Family Historians, 2018)
- Pinpointing the Origin of Family’s Igbo Ancestry with DNA (Roots Revealed, 2017)
- Using DNA Painter to Verify Igbo Origins (Roots Revealed, 2018)
- Chromosome 7 – An African American Connection (Genealogy Under Construction, 2019)
1) I am greatly appreciative of all my survey participants! Without their kind willingness to share their results with me my research would not have been possible! As a minor token of my gratitude I have sent each one of them the Excel file containing all their DNA matches. Aside from giving me access to their results many people also shared useful and very interesting details about their family history with me in PM’s. As far as I was able to verify through such contact or also through public family trees and other publicly available information all my survey participants are of fully Jamaican descent. That is going back on all lines for at least 2 generations. In other words all 4 grandparents being Jamaican-born.
In a few cases I was informed by my survey participants that they were aware of migrant ancestors in their family tree, going beyond my 4 Jamaican-born grandparents criterium. For example 1 South Asian great grandparent or 1 Scottish great-great grandparent. As such lineage is generally in line with Jamaica’s history of incoming migrants I have included these results in my survey. Aside from PM’s and public family trees I also tried to verify the background of my survey participants in other ways. Naturally to the best of my ability. Going by any clues given but in particular: plausible surnames and plausible regional combinations as well as the “migrations” mentioned in AncestryDNA’s Ethnicity Estimates. Taking a cautious approach and preferring to leave out possible survey participants when in doubt.
2) Naturally even within the 6cM-7cM range some genuine IBD matches might appear. But you will have to judge the plausibility on a case by case basis. Due do its Timber filter Ancestry may not always be consistent in how it reports smaller matches. Ancestry may in some cases even under-report the actual amount of shared DNA for your matches. In case your African match is also on Gedmatch or any other DNA testing platform you might want to verify again for yourself if the match is indeed a small match. And in case your parents have also been tested whether the match is perhaps yet an IBD match.
Then again I suspect many of these matches are still likely to be false positives. Also so-called population matches (IBP) are more common than many people might expect. Basically ancient shared origins lead to a great degree of genetic overlap in neighbouring and/or ethno-linguistically related populations. Which can result in identical DNA segments being detected.
This circumstance operates to create DNA matches from all over! Even when technically speaking you are not related to such DNA matches in a genealogically meaningful time frame (let’s say 500 years). I have observed this myself very frequently for both Europeans and Africans. Also several DNA studies have already brought such generic matching patterns to light. Greater awareness of migrations and ethno-linguistic relatedness within Europe and Africa is therefore required for proper interpretation of these smaller matches. See also:
- Dispersals and genetic adaptation of Bantu-speaking populations in Africa and North America. (Patin et al., 2017)
- How Phasing Works and Determining IBD Versus IBS Matches (DNAeXplained, 2015)
- Study Suggests Europeans Are Closely Related (SciTechDaily, 2013)
I also have a feeling that the possible impact of so-called pile-up regions on the validity of African DNA matches is not yet fully realized. However generally speaking the importance of extra scrutiny in such cases is often stressed by genetic genealogists. See also:
- Concepts – Identical by…Descent, State, Population and Chance (DNAeXplained, 2016)
- Excess IBD sharing / Pile-up Regions (ISOGG)
- Small segments and pile-ups – a visualisation (Cruwys News, 2018)
3) Ever since Ancestry’s 2018 update the prediction accuracy of British and Irish lineage has improved greatly. Therefore you can now sort on DNA matches whose regional admixture would fall in line with such backgrounds. Being 100% European and principal regions being either: “England, Wales & Northwestern Europe” or “Ireland & Scotland”. It would probably still be tricky though to separate Britons and Irish from Anglo-Americans or Irish Americans. Unless confirmed also by public family tree details.
I actually find that Ancestry’s “migrations” or genetic communities are already quite predictive of (relatively) recent British lineage though. Especially the “Scottish Highlands” migration was reported a few times, during this survey. In line with my 23andme survey findings for 28 Jamaicans. Based on matching strength “United Kingdom” was reported eight times as “Recent Ancestral Location” (RAL). While “Ireland” was mentioned twice. See also section 6 of this blog post:
4) In May 2017 I already did a scan and analysis of African matches for survey participant JAM15. I found only 6 African matches then. While now I was able to detect 29 most likely African matches! Also her total number of DNA matches increased from 1,554 to 5,370! See also this blogpost:
When it comes to finding Jamaican descended DNA matches it is a whole different ball game! Due to the already existing popularity of DNA testing among Jamaicans, living in either North America or the UK. I have not kept an exact score of it during this survey. But I would estimate that for my survey participants at least a plurality of all DNA matches could be (partially) Jamaican related. When only counting close matches (>20cM) they are certainly a majority (overwhelmingly so). The number of people (over 53,185 most recently) being assigned to the so-called “Afro-Jamaican” migration is a very telling indicator.
5) According to many pundits only continental admixture is to be taken seriously in DNA testing. Sub-continental, a.k.a. ethnicity estimates, a.k.a. regional admixture only being fit for entertainment purposes. I myself have never taken this stance. Preferring to judge each case on its own merits. Attempting to maximize informational value despite imperfections and avoiding source snobbery. Which is why I have conducted my AncestryDNA surveys among both Africans and Afro-descendants in the past. Applying an additional macro-regional framework for extra insight (Upper Guinea, Lower Guinea, Central/Southeast Africa).
Basically combining interrelated & neighbouring genetic regions in order to allow certain regional patterns to show up more clearly. This turned out to be particularly helpful when wanting to explore any rough correlation between aggregated AncestryDNA results for Afro-Diasporans and slave trade patterns. Which I indeed established for the most part. Also more specifically for Jamaicans I believe such an approach can also be beneficial when wanting to reach deeper understanding of Jamaican genetics. See also:
Regional estimates require correct interpretation and each updated version as well as each separate DNA testing company should be judged on its own terms. Then again these admixture results can only take you that far. Which is why I am also exploring the African DNA matching patterns for Jamaicans in this blog post for greater combined insight.
6) For example it would clearly be preposterous to conclude Jamaicans are mostly of Jewish heritage. Going only by the high average number of matches (49) I found for them among my survey group. Being aware also of the minimal associated admixture level puts everything in much better perspective (0.2% on average, 2% being the highest score, see this overview). The average number of Central African matches (1) might be rather subdued on the other hand. However the associated regional admixture scores (indicated by “Cameroon/Congo”, 14% on average) are much higher than for “European Jewish”. And of course also going by historical plausibility and knowing the average degree of overall African admixture (80%) one can already understand how this part of Jamaican genetics is far more significant. Even if not appropriately reflected in Central African DNA matches. Combining both aspects of DNA testing therefore leads to greater overall informational value. Rather than only focusing on DNA matches.
7) Ideally you would expect a great deal of correlation to show up between admixture and associated DNA matches. There are however a couple of circumstances which may get in the way. For my survey I suspect the following factors may have prevented a greater realization of correlation:
- my categories of matches do not always fully correspond with associated admixture. Or also vice versa certain types of regional admixture are to be found among several categories of DNA matches.
- Ancestry’s ethnically skewed customer database is causing lower odds of matching with certain nationalities.
- too few observations (n=30) or too little range in these observations.
For example “Benin/Togo” admixture scores (2013-2018 version) showed a negative correlation (-0.14) with the number of associated DNA matches from either Benin or Togo. I have actually also added Ewe matches from most likely Ghana to this number. Because of close genetic similarities (Ewe results usually showed predominant “Benin/Togo” scores) and greater Ewe representation within Ancestry’s customer database.
The negative outcome is most likely a reflection of “Benin/Togo” being a very ambivalent region which also covers Ghanaian and Nigerian DNA. And therefore “Benin/Togo” is (partially) correlating also with both Ghanaian and Nigerian matches. I have actually also calculated the respective correlations. Between “Benin/Togo” and Ghanian matches it was 0.17. Which is low but still positive. While for Nigerian matches and “Benin/Togo” it was 0.02. So basically no correlation. See also this spreadsheet.
8) Two survey participants (JAM03 & JAM29, see this sheet) did receive several Nigerian DNA matches despite having zero “Nigeria” regional admixture according to the old 2013-2018 version. This is clearly reflective of the inadequate predictive accuracy of “Nigeria” and hence the weak correlation with matches (0.18 see table 2.1). After the 2019 update “Nigeria” estimates generally increased a great deal. For the most part an over-correction seems to have taken place. But still interestingly the correlation between Nigerian matches and Nigerian admixture (2019 version) is much higher: 0.65 instead of 0.18 based on the 2013-2018 version.
9) When I started out with this survey AncestryDNA’s Ethnicity Estimates had not been updated yet. Compared with the previous version (current between 2013-2018) AncestryDNA’s update has caused quite some changes. As discussed in greater detail in this blog post this update may be more beneficial for some people than others. All depending on background. Given the worsened accuracy of “Ghana” this has obviously impacted the results of Jamaicans in a negative way. They have been robbed in a way. So I understand their misgivings 😉 . This is also why I published my previous blog post on 100 Jamaican AncestryDNA results in advance. As I believe the 2013-2018 version remains a better fit for Jamaica’s known African regional roots.
But still these newly updated Ancestry’s results were not determined at random! Firstly the 2018 update basically was a downgrade and therefore understandably some grave flaws had to be corrected. Leading to higher “Nigeria” scores especially. This increase is not coming out of thin air. But is rather based on Ancestry’s greatly improved Reference Panel for Nigeria (411 samples were added!) In itself a primary place of “Nigeria” is not at all implausible for Jamaica, as the Bight of Biafra slave trade was most significant, overall speaking.
Furthermore it is due to the decrease of genetically related and neighbouring regions from which this “Nigeria” increase was made possible. This can be clearly seen when taking into account a so-called macro-regional approach. See overview below which is based on the group averages for 10 Jamaican AncestryDNA results, the original 2013-2018 version and the updated 2019 one. Notice that going by a 3-way breakdown the shares have mostly remained consistent.
Then again it is also through an oversmoothing algorithm and probably an undersampling of “Ghana” that its predictive accuracy has practically crashed now. So for Jamaicans a new update certainly is needed! Still by looking into your African DNA matches especially you may be able to corroborate much of your regional admixture scores. Whether they be old or updated.
*** (click to enlarge)
10) As described in section 2 the correlation between “Ivory Coast/Ghana” and Ghanaian matches was pretty robust already (0.43). In some contrast with other combinations of regional admixture & associated DNA matches. Interestingly also it turned out that the correlation between “Ivory Coast/Ghana” scores with Liberian matches was considerably lower (0.20). Although still positive. Suggesting that for Jamaicans at least “Ivory Coast/Ghana” was indeed mostly predictive of Ghanaian ancestry. But not exclusive of Liberian or even Ivorian ancestry either! In fact I have also calculated the correlation between “Ivory Coast/Ghana” scores and the combined number of Ghanaian, Liberian and Ivorian DNA matches. And this turned out to be higher even than for Ghanaian matches only: 0.52. (see also this spreadsheet).
One should realize that a substantial “Ivory Coast/Ghana” score could include ancestors from various countries, all at the same time. For example a 25% score “Ivory Coast/Ghana” for a typical Jamaican might be traced back to 18 ancestors from Ghana, 4 ancestors from Liberia and 3 ancestors from Sierra Leone. Just to name one hypothetical possibility. DNA matches from either of these countries may be particularly useful to explore such scenario’s. Several survey participants actually had both Ghanaian and Liberian DNA matches! However the frequency of Liberian DNA matches was clearly lower. And for 12 persons no Liberian DNA matches were reported at all. While only one survey participant showed zero Ghanaian DNA matches.
11) I have actually seen a couple of other Madagascar matches being reported for other Jamaicans as well (not incl. in this survey). However I find it striking that the frequency of Madagascar matches seems to be higher among African Americans. I have analyzed the DNA matches for many dozens of African Americans by now. Not all of them receive Madagascar matches. But if they do it is usually in greater numbers and also with greater amounts of shared DNA than the Jamaican profiles I have analyzed so far.
I have a strong suspicion that due to an early founding effect in Virginia and subsequent dispersal due to Domestic Slave trade a diluted but still very detectable genetic Malagasy element has become widespread within the African American genepool. Also to be measured by trace amounts of “Southeast Asian” admixture on 23andme for example. I will investigate this further in a similar survey of DNA matches among African Americans.
12) The person with the second-highest “Southeastern Bantu” score (13%) in my survey (JAM11) did however receive two Southeast African matches (Zambia & Zimbabwe). And the average amount of shared DNA was quite solid actually (8 cM, see this sheet). In addition to also 3 Congolese matches. Furthermore he also received an Afro-Arab match (UAE) with whom he shares only Central African regional admixture (see also section 5). I have a hunch all these matches might be interconnected though. And possibly to be traced back to one particular family line. Although of course other ancestral scenarios may also be implied. A chromosome browser and triangulation could offer more insight.
13) The frequency of population matches (IBP) is more common than many people might expect. Many people uncritically accept these type of matches as implying that they have identifiable ancestors from “exotic” places. Aside from being caused by endogamy I suppose population matches might also be a reflection of (pre)historical migration patterns. Often not verifiable by genealogy but more so correlating with rather ancient population movements across time and space.
This circumstance may hold some far-reaching implications. IBP matches are not to be dismissed in all cases. However they do require careful interpretation. In the African context countless migrations from the past may result in IBP matches. Perhaps the most impactful ones have been the Fula migrations across the Sahel corridor, from Upper Guinea into Sudan. As well as the Bantu migrations from southeast Nigeria/Cameroon into Central, East and Southern Africa.
My previous African DNA matches findings for Cape Verdeans (see this link) certainly seem to testify to the significance of the Fula migrations. The elevated frequency of presumably Hausa-Fulani matches from Nigeria perhaps being most evocative in this regard! However when performing similar surveys for other parts of the Afro-Diaspora I am quite certain that also the significance of the Bantu migrations will become apparent in matching patterns. At times confusingly so. This has indeed also surfaced within this Jamaican survey. As can be seen from the unexpected matches from southern Africa as well as Kenya.
I have myself already observed on 23andme how Kenyans are able to receive unexpected Zimbabwean DNA matches. Seemingly due to the genetic legacy of the Bantu Expansion from many centuries or even several millennia ago. Likewise Afro-Diasporans might receive Kenyan matches due to shared Bantu origins from Central Africa (Angola/Congo). In a recently published research paper it has been revealed that Angolans were having IBD matches with people from South Africa and also from Kenya/Uganda! See:
- Countries of Ancestry Tool on 23andme (African DNA matching patterns)
- Number of IBD segments among Bantu speakers (Patin et al, 2017)
14) I was not able this time to perform a so-called IBD (Identical By Descent) check. Because I did not have access to the profiles of the parents of my survey participants. During my earlier survey of DNA matches among 50 Cape Verdeans I was however able to determine if African matches were indeed inherited by way of one of the parents. This was possible for a subset of eight persons. For seven survey participants I could only use the DNA matches from one single parent when performing the IBD check. So this exercise was not fully complete but still already useful. See also footnote 24 of blogpost below for greater discussion:
Obviously much more data is needed for any generalizing inferences. But reviewing my research outcomes in this table it is perhaps already telling that I did not come across any IBD matches at all when analyzing unexpected Northeast African matches for Cape Verdeans (grouped under “Other African”). Underlining how historically unexpected DNA matches with small amounts of shared DNA (~7cM) will often turn out to be false positives indeed.
15) This occurrence of unusual African matches certainly is intriguing and can at times also be corroborated by additional clues. Including also regional admixture. During this survey it turned out that the shared DNA segments between my Jamaican survey participants and their North and East African matches still pointed towards West or Central African DNA. However I can imagine it may also be the other way around in a few cases. Whereby distinctive regional admixture is able to corroborate unexpected matches. In fact my survey participant JAM10 with 2 Sudanese matches as well as 1 Algerian one, did have a distinctive “Africa North” score! No less than 2% in the original 2013-2018 version (see this screenshot). However due to oversmoothing probably this type of admixture is no longer detected. Possibly now included in her “Mali” score instead.
Generally speaking it will be (usually minor) scores for “Eastern Bantu”, “Northern Africa”, “Middle East”, “Ethiopia & Eritrea” and “Somalia” which might act as tell-tale signs. Although still not per se conclusive. As an alternative you could also look for any of the equivalent regions on 23andme. Possibly more accuracy to be expected over there. Also with trace amounts. Aside from the newly updated Middle East & North African regions (see this link) these categories on 23andme are: “Southern East African”, “Ethiopian & Eritrean”, “Somali” and “Sudanese”. Especially the latter category may often also be indicative of Sahelian DNA though. Either way, from my survey findings sofar these rather exotic types of regional admixture are very uncommon for Trans-Atlantic Afro-descendants. Only exception being “Southern East African”. However the Northeast African type of admixture is usually completely absent or only reported in minuscule amounts <1%. See also:
- Speadsheet with Afro-Diasporan 23andme results
- African breakdown after 2019 update on Ancestry across Afro-Diaspora
16) It is useful as well to take into consideration wider matching patterns. For example my survey participant JAM19 had two Sudanese matches. And the shared regional admixture was “Mali”. Making it quite likely that these two Sudanese matches (close relatives most likely because managed under the same profile) are of (partial) Fula descent. In addition however JAM19 also had 4 other Upper Guinean related matches! Including atleast one quite likely Fula match! The same goes for my survey participant JAM10 for whom I found 1 Algerian match and also the same two Sudanese matches as for JAM19. And in addition again also 1 Fula match! (see this sheet).
Being aware of the Fula migrations contributes to a greater understanding of these matches and how they (possibly) may be inter-related. A typical ancestral scenario might involve one Fula man residing in for example Senegambia or Guinea in the mid 1700’s. Due to local warfare he ends up being deported as a captive to Jamaica. His brother however decides to migrate eastwards as many Fula people had been doing then for quite some time already. He first settles down in northern Nigeria (Sokoto empire). Where either his children and/or grandchildren may have intermingled with the native Hausa people. Subsequently the migration eastwards is being continued by his descendants into Sudan. Resulting in a presentday DNA match between a Sudanese with a Jamaican! See also my discussion of Hausa-Fulani DNA matches being reported for Cape Verdeans in foot note 16.
17) Generally speaking I believe that any DNA test result indicating East African ancestry should always be critically scrutinized. I tend to be very sceptical about the degree or frequency of “East African” DNA results reported for Jamaicans as well as for other Afro-Diasporans from the Americas. Because this does not fit well with historical plausibility nor cultural retention. Of course one must remain open minded and within it self this topic of any possible East African connection for the Atlantic Afro-Diaspora is quite intriguing. Hypothetically speaking in rare and individual cases I suppose it might be possible to have one single East African ancestor. However I am assuming it would be greatly diluted then in most cases.
But certainly such atypical cases do not justify the currently much inflated level of so-called East African DNA results being reported by various DNA testing companies, across the board. Either haplogroups, admixture scores or DNA matches suggesting such connections. The tricky thing is that DNA testing of course is no exact science. Due to faulty algorithms, lack of reference populations etc.. On all fronts, also including DNA matches! Which can very well be IBS or false positives. In particular smaller matches (see section 1 or also this chart). Especially the implied time framing is often unclear. I highly suspect DNA test results suggesting East African ancestry are often merely a consequence of VERY ancient population migrations across the continent (going back millennia instead of centuries). Something which would also be detected among actual West or Central Africans. Irrelevant therefore from a genealogical perspective (last 500 years or so).
I think it helps to be as specific as possible when outlining such results. Making a distinction between various parts within East Africa. Many people may already be aware of the legitimate Southeast African connection (mostly Madagascar & Mozambique). Strictly speaking East Africa for me would be the Swahili speaking countries: Tanzania, Kenya, Uganda and possibly also eastern DRC, Ruanda/Burundi. While Northeast Africa would be Somalia, Ethiopia, Eritrea, Djibouti and Sudan.
Now when it comes to historically documented ancestral connections between these latter areas and Jamaica as well as the Americas it is far less apparent than for Southeast Africa. Although it is known that some atypical Trans-Atlantic slave voyages did depart from the Swahili Coast: Mombasa (which used to be ruled by the Portuguese!) and also Zanzibar. But going by actual numbers as well proportionally this flow of people was quite minuscule. Going by documented slave voyages the East African share in Trans-Atlantic Slave Trade might be less than 0.1% (=6,324/6,709,327; see also note 1 of this page).
18) I like to emphasize that no fictional national averages are implied. And obviously individual family trees may be far more complex than reflected by these preliminary survey group averages! My findings firstmost reflect the limited number of samples which were available to me. Even so I do think that my previous sample size for regional admixture (n=100) was pretty robust already. My present sample size for this DNA Matches survey (n=30) is of course somewhat smaller.
But actually as a crude rule of thumb it is often stated that n=30 is a large enough sample size for most standardized types of research. Also my samples have been randomly picked and are – as far as I have been able to tell – from various parishes within Jamaica as well as from various social backgrounds. Combined also with the historical indications provided I do therefore strongly suspect that my findings might correlate more or less to what is to be found within the Jamaican genepool as a whole.
19) A Jamaican with total African being >90% might very well still have a majority of African-born ancestors to be traced back to the mid 1700’s or even earlier. I imagine this would be the case especially for many Maroons! Also a Jamaican with total African <70% may in fact be descended from a relatively recent union between an African contract labourer and an Englishman in the late 1800’s. Just to name one random possibility.
Furthermore unlike the Hispanic Caribbean the various waves of African regional slave trade to Jamaica are mostly overlapping and not unique to any given time period. For example Nigerian lineage may be traced back to both the late period of slave trade (probably highest odds) but also the early 1700’s (see this table). It is certainly not my intention to overlook or downplay this wide array of ancestral options!
I also find it striking for example that all of my survey participants were assigned to either the “Northern” or “South-Central” communities. But none of them was assigned to both. Even when (partial) St. Elizabeth origins were mentioned to me for several survey participants within the “Northern” community. While also persons in the “South-Central” community often had partial parish origins from the north or east. Quite telling perhaps also that one person (JAM06) whose family is from Manchester on both sides did not get assigned to “South-Central” but still ended up in “Northern”. See also:
20) As a prerequisite I suppose you would need to compare results for people with very deep roots in only one single particular parish or county on all family lines. At least all 4 grandparents born in the same parish. Further back I suppose having family lines from adjoining or dissolved parishes could still also be acceptable. In my limited survey however there were very few people who fulfilled this criterium. I did receive information from almost all of my survey participants about their recent parish origins (see column B in this spreadsheet). However this was not always complete. Furthermore many times they may also not be aware or even misinformed of all their family’s parish orgins.
Not surprising perhaps given a great deal of internal migration within Jamaica. Especially for people of recently urbanized background. I am assuming that actually also already during Slavery there may have been a fair amount of randomized moving around of enslaved people. Due to sales of estates, internal slave trade etc. Jamaica might be one of the Greater Antilles. But of course it is still a relatively small island. Then again due to geographical circumstance causing relative isolation some parishes might have had a distinctive population formation. Including specific African lineage which could more prevalent than elsewhere. Fortunately many such clues are obtainable for Jamaica.
21) It is a bit peculiar that 2 of my survey participants (JAM08 & JAM11, see this spreadsheet) without any South Asian admixture still did have 1 South Asian DNA match each. Because of the compare ethnicity tool I was able to verify that these matches are indeed 100% South Asian. At least according to Ancestry. One of these matches is actually quite small (6cM) and atypical (because from Sri Lanka!) and therefore likely a false positive. But the other one is quite robust (12 cM). Both of these survey participants also did not receive any trace amount of South Asian admixture with Ancestry’s 2013-2018 version (see column E in my spreadsheet).
Then again from my observation Ancestry has never been particularly good with reporting of trace amounts of admixture. In the past mysterious “Melanesia” scores were often combined with “Asia South” scores for example (see this page). “Asia Central” scores often turned out to be false. And the previous 3% Asian score for JAM19 also was in fact merely a fluke! There are of course some inherent difficulties when wanting to avoid “noise” scores. But I find that 23andme performance is much better in this regard. Would be interesting to see if my survey participants might yet score some tiny South Asian score on 23andme. But actually it might also be the other way around! Which is to say that the South Asian matches I found may actually not be 100% South Asian genetically speaking.
Due to Ancestry’s new oversmoothing algorithm smaller segments of distinctive admixture often get skipped after the 2018 & 2019 updates (see this blogpost). However Ancestry did do a good job for this match below for whom I could establish that the shared regional admixture they have in common is actually the 1% “England, Wales and Northwest Europe”. And not the 99% South Asian admixture. Notice also the Portuguese surname, indicative of a Indo-Portuguese connection perhaps. All in all a good reminder to maintain scrutiny but at the same time also aim for maximizing informational value 😉
***(click to enlarge)
22) As can be seen in my spreadsheet only 10 of my survey participants received Jewish DNA matches. However only 4 of them showed any “European Jewish” admixture! At least according to Ancestry’s 2019 update. I have actually also included Ancestry’s 2013-2018 estimates in column E (check also notes). Because due to Ancestry’s new oversmoothing algorithm smaller segments of distinctive admixture often get skipped after the 2018 & 2019 updates (see this blogpost). And then it turns out that all of these 10 persons did at least receive tiny ( <1%) “European Jewish”, “Middle East” or “Caucasus” scores. Probably more so correlating with Sephardi lineage than Askenazi lineage.
23) In this matter a chromosome browser to establish the ethnic/regional origin of the shared DNA amounts with your matches would be of tremendous help! As actually the “compare ethnicity” feature is inconclusive for these two crucial Sephardi Jamaican matches. No shared regional admixture being indicated! Probably the 1% “Iran/Persia” score for JAM13 being a misreading of actually “Middle East” admixture.
24) In fact the regional summaries shown after scanning by DNAGedcom are not consistently in alignment with one particular version of Ancestry’s Ethnicity Estimates. From my current observation most of them are still in line with Ancestry’s flawed update from 2018. While a smaller number of matches shows the newly updated format from 2019. While some of them will even reflect the initial 2013-2018 version! Naturally this can create a great deal of confusion if you are not aware of how Ancestry’s last two updates have impacted the African breakdown for Africans themselves. For greater understanding see my surveyfindings performed among African customers after each update:
25) From what I have seen many Africans on Ancestry tend to not have public family trees. And if they do it is usually not going back that many generations. Not beyond the 1900’s at least. One also has to keep in mind that traditionally speaking many African cultures keep track only of the direct paternal and/or direct maternal line. All other family lines, starting for example with one’s paternal grandmother or maternal grandfather and all their predecessors are often not recorded going back more than 3 generations.
Of course for most Afro-Diasporans there will also be a great deal of missing information going beyond the 1900’s. So generally speaking the chances of finding a mutual ancestor by way of comparing family trees are quite slim. Nonetheless I do think that several advanced genetic genealogy tools/techniques might be fruitful in learning more about which possible family line the common ancestor with your African match is to be associated with.
Depending on the amount of shared DNA with your match you can already get an idea of how solid the match could be. However by testing close relatives, preferably your parents or older generations, it makes it much more easier to establish if your match is indeed a socalled IBD match (Identical By Descent). And also on which family line your common ancestor may be placed.
Triangulation and DNA Painter may also give you more insight. This will be very tricky given scanty information and will also require a lot of patience. But it might still be worthwhile for eventually zooming in closer to your West African origins along a certain family line or even actually identifying a West African ancestor! Of course Ancestry is not really helpful in this regard as they do not provide a chromosome browser nor do they provide the location of shared DNA segments. However if any of your African DNA matches is also on Gedmatch, 23andme or MyHeritage you could get things started I guess. For a very inspirational blog post see:
- Using DNA Painter to Verify Igbo Origins (Roots Revealed, 2018)