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

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

Table 1 (click to enlarge)

DNA matches for 50 CV's

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

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Table 2 (click to enlarge)

African matches

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

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

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

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

Part 2 of this blogseries will have the following topics:

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

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

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100 Cape Verdean AncestryDNA results

In October 2015 I published my first preliminary survey findings based on 23 Cape Verdean AncestryDNA results (see this link). Right now, almost three years later, I have managed to collect a sample group which is four times greater. Consisting of no less than 100 AncestryDNA results of fully Cape Verdean-descended persons! Even though this quadrupled sample size is obviously still limited it will most likely provide a greater insight in the various ways how “Caboverdeanidade” can be described. Genetically speaking that is. And obviously when applying the regional AncestryDNA format, with all its enhanced features as well as its inherent shortcomings  😉

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Click on this banner to reach Cape Verde DNA, Inc: the biggest online community of Cape Verdean Genealogy & DNA enthusiasts! On Augustus 4 & 5 a pioneering Cape Verde DNA and Genealogy Conference will be held! See this link for more details.

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In this blog post I will discuss the main differences with my previous findings from 2015, which were focused on the African breakdown solely. And in addition I will also present some new statistics and background information on the European and other non-African origins of Cape Verdeans as reported by AncestryDNABelow an overview of all the topics I will cover:

  1. Background details of my 100 Cape Verdean survey participants
  2. To be Cape Verdean is to be mixed?
  3. Upper Guinean roots = “Senegal” + “Mali”
  4. Beyond Upper Guinea: valid outcomes or misreading by AncestryDNA?
  5. European breakdown reflecting mostly Portuguese ancestry?
  6. “Africa North”, “Middle East”, “European Jewish” and other minor regional scores
  7. Upcoming update of AncestryDNA’s Ethnicity Estimates

Follow these links for my complete survey data & research methodology:

Table 1 (click to enlarge)

cvstats

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Chart 1 (click to enlarge)

Primary regions

This frequency of regions being ranked #1 (regions with the highest amount in either the African or European breakdown) is perhaps the best indicator of the main ancestral components for my Cape Verdean survey group. However only in an extra pronounced degree. For more nuance see the group averages in the next sections.

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Screenshots of individual results (rightclick and open in new tab to enlarge; island origins shown below)

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More charts and analysis when you continue reading!

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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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African DNA Cousins reported for people across the Diaspora

This blog post features the AncestryDNA results of 8 persons from 7 different countries. In particular i will list the (most likely) African DNA matches i was able to find for each profile. Using the tutorial i blogged about in my previous blog post:

Naturally this overview is not meant to be representative per se because these persons are in the first place individuals with unique family trees. It is mainly to show the variation across the Afro-Diaspora. Nonetheless I strongly suspect that many patterns to be observed will still be valid as well for other people of the same nationality or ethnic (sub)group.

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Diaspora Overview

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For this overview I specifically chose people with one single predominant African regional score on AncestryDNA. In order to see how Ancestry’s “Ethnicity Estimate” lines up with predicted African DNA matches. More detailed analysis will follow in this blog post. If you continue reading you will also come across a section featuring inspiring stories of people who were able to reconnect with their African kin through DNA testing.

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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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Cape Verde Slave Census of 1856 (part 2)

Origins from across Upper Guinea, not just from Guinea Bissau

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Map of Upper Guinea, western Mali should also be included for ancestral purposes

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Bissau, Cacheu, Cape Verde Slave Census of 1856

REGIONAL ORIGINS (combined)

Total ethnically specified: 1,615
Guinea Bissau’s Coastal Zone: 843 (52% of ethnically specified)
Upper Guinea Interior: 670  (42% of ethnically specified)
Senegal, Guinea & Sierra Leone: 102 (6% of ethnically specified)

TOP 3 ETHNIC ORIGINS (combined)

Mandinga (Upper Guinea) 262 – 16% of ethnically specified
Tilibonca (Upper Guinea) 229 – 14% of ethnically specified
Bijago (Guiné Bissau) 226 – 14% of ethnically specified
Source: Hawthorne (2003)

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In the first part of this blogpost i already discussed the main Guinean Bissau origins for Cape Verde according to its 1856 slave census, in this second part i will continue exploring origins outside of Guiné Bissau. When asked about their mainland African roots many Cape Verdeans might assume they only have ancestry coming from Guiné Bissau, this is however not completely true. It’s indeed correct that Guiné Bissau shares a very long and intimate history with Cape Verde. Both countries being ex-Portuguese colonies, united in their independence struggle during the 1970’s. Because of ever increasing English and French encroachment the formal Portuguese influence area within Upper Guinea during the 1600’s was already pretty much confined to modernday Guiné Bissau and Casamance (a region in southern Senegal which only was ceded to the French in 1888 and where a Portuguese-based Creole is still being spoken!).

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Cape Verde Slave Census of 1856 (part 1)

40-anos-da-Independância-de-Cabo-Verde-Unilab-550x275

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Cape Verde, an independent country since July 5th 1975!
Cape Verdeans: an indomitable people for more than 500 years!

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Cape Verde Slave Census of 1856

SUMMARY

Number of slaves 5,182
Creole (i.e. born in Cape Verde) 4,266 (82% of total)
African (mainland) 867 (17% of total)
African specified ethnically 130 (2,5% of total)

TOP 3 BREAKDOWN OF AFRICAN BORN SLAVES

Mandinga (Upper Guinea) 34 – 26% of African specified
Fula (Upper Guinea) 19 – 15% of African specified
Bijago (Guiné Bissau) 18 – 14% of African specified
Source: Carreira (1972)

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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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