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.