Update: Afro-Diasporan AncestryDNA Survey (part 2)

In May 2016 I published the first summary of my Afro-Diasporan survey findings based on 707 results for 7 nationalities (see this blog page). My survey has been ongoing ever since. Right now an update of AncestryDNA Ethnicity Estimates seems even more imminent than it was in 2016 (when it was canceled in the beta phase). So that’s why I will yet again provide a “final” overview of my survey findings 😉 See this link for the first part of my findings which is focused solely on the African breakdown:

In order to provide a broader perspective on the complete DNA make-up of Afro-Diasporans I have this time also analyzed the non-African regional scores on AncestryDNA. Enabling a continental breakdown for my 8 sample groups. Mainly based on 860 results for people from 8 nationalities1. Although the total number of results and nationalities in my survey is even greater.

Generally speaking also the non-African group averages seem to be reasonably in line with historical plausibility. Amerindian, Asian and Pacific trace-amounts are not being left out. These scores are often labeled as low confidence regions and dismissed as just “noise”. Rightfully so in some cases. But given correct interpretation and proper follow-up research at times these scores can still potentially lead you to distinctive ancestors. Furthermore my survey results are now also allowing for a more detailed discussion of the European breakdown as being reported for Afro-Diasporans.

I would like to underline right from the start that my findings are not intended to represent any fictional national averages! The group averages I have calculated for my sample groups are neither absolute or conclusive but rather to be seen as indicative. Obviously several shortcomings may apply. One main aspect to take to heart is that there will always be individual variation around the mean. Given correct interpretation I do believe these group averages suggest insightful tendencies though for each of my 8 sample groups. They also mostly comply with the findings of admixture studies published in peer reviewed journals, or at least the ones I am aware of.2

Chart 1 (click to enlarge)

Continental breakdown

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Update: Afro-Diasporan AncestryDNA Survey (part 1)

In 2013 AncestryDNA updated their Ethnicity Estimates to include a detailed breakdown of West African DNA. Pioneering when compared with other DNA testing companies. Soon afterwards I started collecting AncestryDNA results in an online spreadsheet in order to conduct a survey of the African regional scores being reported by AncestryDNA. At first only for people of the Afro-Diaspora and later on also among Africans. My main research goal has always been to establish how much the AncestryDNA results on an aggregated group level can already (despite limitations of sample size and other shortcomings) be correlated with whatever is known about the documented regional African roots for each nationality. As well as to improve correct interpretation of personal results.

In May 2016 I published my first summary of my Afro-Diasporan survey findings based on 707 results for 7 nationalities (see this blog post). My survey has been ongoing ever since. Right now an update of AncestryDNA’s Ethnicity Estimates seems even more imminent than it was in 2016 (when it was canceled in the beta phase). So that’s why I will yet again provide a “final” overview of my survey findings 😉 . Mainly based on 1,264 results for people from 8 nationalities. Although the total number of results and nationalities in my survey is even greater.

A major addition is the inclusion of 45 Brazilian results. Their predominant Central African profiles (as measured by both “Southeastern Bantu” and “Cameroon/Congo”) are quite striking when compared with my other sample groups. This outcome reinforces how the African breakdown on AncestryDNA has been reasonably in alignment with historically documented origins of the Afro-Diaspora. Unlike any other DNA testing platform I’m aware of and therefore not to be lightly dismissed despite inherent imperfections.

In the second part of this blogseries I will also provide an overview of the non-African regions (Amerindian, Asian, Pacific etc.) being reported for Afro-Diasporans. As well as a more detailed analysis of their European breakdown.

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This frequency of regions being ranked #1 (regions with the highest amount in the African breakdown) is perhaps the best indicator of which distinct African lineages may have been preserved the most among my sample groups.”

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Chart 1 (click to enlarge)

Afro piechartsa

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DNA matches reported by 23andme for 75 Africans

Wishing to share the vibranium 😉 I have created a new page featuring the DNA matches reported by 23andme for 75 Africansall across the continent. These results were collected by me in 2015 when 23andme’s Countries of Ancestry (CoA) tool was still available.

My survey results might have limitations in several regards but I do believe these African CoA results can still reveal relevant tendencies in DNA matching. I intend to compare these preliminary matching patterns eventually with my more recent findings for Africans who tested on Ancestry. I provide detailed background info as well as screenshots of the individual results on this page:

(click to enlarge)

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“Benin/Togo” also describes DNA from Ghana & Nigeria

I have created a new page featuring the AncestryDNA results for West Africans from the following countries: Liberia, Ivory Coast, Burkina Faso, Ghana, Togo & Benin. I will create a new section for the remaining part of West Africa (Upper Guinea) shortly. The number of results I have collected so far might be minimal but already my survey findings turn out to be quite insightful. I also provide some statistical data, analysis and relevant context. Follow this link to view the page:

In addition I also discuss the implications these findings might have for Afro-Diasporans in an attempt to improve proper interpretation of their West African regional scores, in particular for “Ivory Coast/Ghana” and “Benin/Togo”. One of these implications I will also discuss in greater detail in this blog post:

“Benin/Togo” is also predictive of Ghanaian & Nigerian DNA

The so-called “Benin/Togo” region seems to be quite predictive of Beninese origins (based on two results). However in addition ancestry from eastern Ghana and southern Nigeria might also be described by this region. You will need to perform your own follow-up research in order to find out more specifics.

Map 1 (click to enlarge)

Benin Togo

Source: ancestry.com

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Chart 1 (click to enlarge) 

Stats (GH=22)

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“Ivory Coast/Ghana” also describes Liberian DNA

I have created a new page featuring the AncestryDNA results for West Africans from the following countries: Liberia, Ivory Coast, Burkina Faso, Ghana, Togo & Benin. I will create a new section for the remaining part of West Africa (Upper Guinea) shortly. The number of results I have collected so far might be minimal but already my survey findings turn out to be quite insightful. I also provide some statistical data, analysis and relevant context. Follow this link to view the page:

In addition I also discuss the implications these findings might have for Afro-Diasporans in an attempt to improve proper interpretation of their West African regional scores, in particular for “Ivory Coast/Ghana” and “Benin/Togo”. One of these implications I will also discuss in greater detail in this blog post:

“Ivory Coast/Ghana” is also predictive of Liberian & Sierra Leonean DNA

The socalled “Ivory Coast/Ghana” region is indeed quite predictive of both Ghanaian and Ivorian origins. However in addition ancestry from Liberia and to a lesser degree (southern) Sierra Leone might also be described by this region. You will need to perform your own follow-up research in order to find out more specifics.

Map 1 (click to enlarge)

IvcGhana region

Source: ancestry.com. (text in red added by myself)

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Chart 1 (click to enlarge) 

Stats (GH=22)

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AncestryDNA Results Across the Diaspora

In 2013 AncestryDNA updated their Ethnicity Estimates to include a very detailed breakdown of West African ancestry (see this article). Soon afterwards I started collecting AncestryDNA results in an online spreadsheet in order to conduct a survey of the African regions being reported by AncestryDNA, among both African Americans as well as other Afro-descended nationalities. Attempting to establish how much the AncestryDNA results on an aggregated group level can already (despite limitations of sample size) be correlated with whatever is known about the documented regional African roots for each nationality.

Rumour has it that AncestryDNA will shortly start rolling out a new update of their Ethnicity Estimates. So it seems the time is right to finalize my survey. The sample size for most groups appears to be suffciently robust now to allow a meaningful intercomparison. In the AncestryDNA section of my blog (see the menubar) you can find a detailed summary of my survey findings based on 707 results for 7 nationalities:

Gathering all the results was a great learning experience. It has been a very satisfactory project! My survey report merely represents my personal attempt at identifying generalized, preliminary and indicative patterns on a group level inspite of individual variation. Everyone has a unique family tree of course first of all.

I would like to thank again all my survey participants for sharing their results with me. I am truly grateful for it!

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This frequency of regions being ranked #1 (regions with the highest amount in the African breakdown) is perhaps the best indicator of which distinct African lineages may have been preserved the most among my sample groups.”

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FREQ #1 regions

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Documented African Roots of Dominicans

Lemba 4200976_African ethnonyms in Dominican historical sources: 1547-1606

SUMMARY

Estimated number of Africans: 9,648 – 30,000
African origins specified: 79

TOP 3 BREAKDOWN OF AFRICAN BORN SLAVES

Bran” (Guiné Bissau) 15 – 19% of African specified
Zape” (Sierra Leone) 15 – 19% of African specified
Biafara” (Guiné Bissau) 10 – 12% of African specified
Source: Deive (1980, p.239).

Even though this summary is based on a rather small sized dataset (n=79) and reflecting only a limited timespan, there are many indications from other Hispanic American countries to confirm these 3 ethnic groups from Upper Guinea having a significant presence in the Dominican Republic throughout the 1500’s. But they were not the only ones in that particular timeperiod of course and in later decades/centuries the ethnic compostion of Africans within Hispaniola would change constantly with other ethnic origins from Lower Guinea and Central Africa becoming more prevalent.

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African origins of Hispanic Caribbeans according to DNA studies

Moreno-Estrada, (2013) - Fig.6A

Reconstructing the Population Genetic History of the Caribbean (Moreno-Estrada et al., 2013)

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We find evidence of two pulses of African migration.The first pulse—which today is reflected by shorter, older ancestry tracts—consists of a genetic component more similar to coastal West African regions involved in early stages of the trans-Atlantic slave trade. The second pulse—reflected by longer, younger tracts—is more similar to present-day West-Central African populations, supporting historical records of later transatlantic deportation.” (Moreno-Estrada et al., 2013, p.1)

“Overall, we found evidence for a differential origin of the African lineages in present day Afro-Caribbean genomes, with shorter (and thus older) ancestry tracts tracing back to Far West Africa (represented by Mandenka and Brong), and longer tracts (and thus younger) tracing back to Central West Africa.”  (Moreno-Estrada et al., 2013, p.11)

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Specifying the African Origins of the Afro Diasporan Genome (part 1)

Montinaro (2015) - Fig. 1 Samplegroups & Clusters

Unravelling the hidden ancestry of American admixed populations (Montinaro et al., 2015)

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Montinaro (2015) - Supplement - 3way Breakdown

Own calculations based on “Unravelling the hidden ancestry of American admixed populations” (Montinaro et al., 2015)

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“Although our sampling of Africans is incomplete, we see variation among groups in similarity to present-day populations from different parts of Africa. In all groups, the Yorubans from West Africa are the largest contributor, confirming this region [Lower Guinea] as the major component of African slaves” (Montinaro et al., 2015, p.3)

“In addition, more than 30% of the total slaves arriving in mainland Spanish America up to the 1630s came from Senegambia, and we accordingly find that the relative contribution from the Mandenka is higher in all areas historically under the Spanish rule.(Montinaro et al., 2015, p.4)

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Locating Afro-Diasporan haplogroups within Africa

Dissecting... (Tabel S6, country breakdown)a

Dissecting the Within-Africa Ancestry of Populations of African Descent in the Americas (Stefflova et al., 2011)

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Limitations of our study

Our database and analyses have several limitations. First, there remains limited data from W/WC Africa, where the published literature does not cover Ivory and Gold Coasts. Thus, the analysis of genotype data is limited by the available published data.”  […] 

“Second, mtDNA is a single locus that can inform us only about group maternal ancestry and needs to be complemented with study of NRY and AIMs. While NRY analysis is complicated by limited resolution and coverage of the published data in Africa as well as Bantu speakers’ migrations.” (Stefflova et al., 2011, p.7)

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