Chromosome 7 - An African American Connection

Chromosome 7 - Myself [Personal Photo]

With the continued use of DNA Painter, I have been able to see (in a sense) my results through a more magnified lens. Being able to break down genetic cousins via a comparison to my other tested family members has allowed me to better parse down a bit from which branch of my tree they come from. To learn more about DNA Painter you can read my previous post. As I continued to add cousins to my DNA Painter, I noticed that on Chromosome 7, I matched up with a few cousins via my mother's side of the family that had no known connection to Puerto Rico. Intrigued I decided to continue exploring this specific segment and set of cousins, two of which were African American.

European Ancestry - Spanish & Portuguese [Personal Photo]

Above you can see the highlighted segments in my Chromosome 7 that are attached for example specifically to Spanish and Portuguese DNA. My focus however are to the smaller segments that are cut up and distributed more unevenly across Chromosome 7 - amongst those pieces of DNA you can see Native American, Congolese, Senegambian & Guinean, and Ashkenazi Jewish. Knowing where these segments lay and where your cousins fall amongst them may be helpful to better understanding the genetic diversity of your ancestor from which you descend. Keep in mind that this doesn't mean that ancestor was 100% Native American, for example, but carried those genes in that chromosome which allows you to match with other cousins.

Mixed Ancestry - Indigenous, African, and Jewish [Personal Photo]

Simple Generational DNA

Remember that just because you match with someone on a certain segment of DNA doesn't mean that all of your siblings for example will match them as well. Each sibling may receive a range of combinations that might be similar or a bit different to your own. In a "simple generational" comparison, looking at my brothers and myself on Chromosome 7, you can see there is a difference in inheritance on that section. Below you can see exactly what I mean:

Chromosome 7 - Myself  [Personal Photo]

Chromosome 7 - Older Brother [Personal Photo]

Chromosome 7 - Younger Brother [Personal Photo]

My older brother for example received a Congolese + Senegambian/Guinean segment towards the end of his Chromosome 7, we both share the Congolese bit while my little brother seems to have received a mix of Native American and Senegambian/Guinean but no Congolese DNA in that segment. Notice however that he does share the Ashkenazi DNA segment with me while my older brother does not. DNA is crazy, huh?!

To strengthen my theory here a bit more, I searched both of my brothers' DNA relatives on 23andme. My younger brother does not share the African American cousins while my older brother does share them on his relative list. Analyzing this on a deeper level would probably show us that my younger brother received a different segment from a different maternal ancestor compared to my older brother and I who received this same bit from the same maternal ancestor.

Complex Generational DNA

Looking backwards a few generations, you can see where these segments come from. I knew going in that these African American cousins matched me via my mother, I have been fortunate enough to have tested my mom along with her parents which allowed me to easily make this distinction. The question now was: Would my mother, and one of her parents also have Congolese DNA on this segment? See below to see where the Congolese DNA segment can be found: 

PARENTS' GENERATION

Chromosome 7 - Mother [Personal Photo]

Chromosome 7 - Maternal Uncle [Personal Photo]

GRANDPARENTS' GENERATION

Chromosome 7 - Maternal Grandmother [Personal Photo]

Chromosome 7 - Maternal Grandfather [Personal Photo]

GREAT-GRANDPARENTS' GENERATION

Chromosome 7 - Maternal Great-Grandfather [Personal Photo]

As you can see, my mother and one of her brother's inherited the Congolese DNA (there's another sibling but currently he is not tested). At the next level you can see that this piece of DNA was inherited from their mother (my maternal grandmother) and not their father (my maternal grandfather). At the 3rd generation you can see that my maternal great-grandfather did not have this Congolese DNA, which would mean that they inherited it from my great-grandmother. Testing my grandmother's siblings would probably give me a better idea as to who inherited which DNA from my great-grandmother amongst them. 

DNA Painter

Using my DNA matches from 23andme I began to set out which cousins I received from my maternal grandfather and maternal grandmother - here on out just referred to as "grandmother/grandfather" seeing as how this is all on my maternal side. From there I was able to see who matched my great-grandfather and any cousins who might match anywhere in between. Below you can see that the yellow bit inherited is from my grandfather while the rest of the chromosome is from my grandmother. The light green denotes my great-grandfather while the darker green my grandmother, these dark green segments I imagine are from my great-grandmother. The beige color is for a cousin who matches me with 2nd great-grandparents via my Meléndez-Sánchez great-grandfather while the purple segments are cousins I match via my Dávila-Orozco great-grandmother. As more cousins match me on these sections with a paper-trail the better I will be at figuring out from which great-grandparents and further this DNA came from.

DNA Painter- Chromosome 7 [Personal Photo]

Chromosome 7 - Luis Rivera [Personal Photo]

Looking at where the Congolese DNA is, you can sort of see that it falls where the dark green chunk of DNA my grandmother passed onto me in Chromosome 7. Expanding the matches, you can see where various of these cousins fall. 

Expanded DNA Matches - Chromosome 7 [Personal Photo]

Above you can see that the 2 African American matches fall in the square of matches inherited via my grandmother. In that same box are 3 more segments on top, these being Puerto Rican cousins. Usually when matches fall under one another, it means that they probably share DNA and are related to you via a same ancestor as they are to those cousins as well. The question now was: Could these African American matches also share DNA with those Puerto Rican matches on Chromosome 7? Would they also match each other? It was time to test out my question!

Taking the cousin who shares 15cm with me, I compared that cousin to my Puerto Rican cousins and to my other African American cousin match within that shared segment. Below you can see that YES! they do share DNA with one another, both the African American cousins and to the Puerto Rican cousins. This mostly likely means that somehow on my grandmother's side of the family we all descend from a shared ancestor(s). With the ranges being between 11-16cm, this would mean that the relationship would be rather far back. DNA Painter estimates that at those CM the match lies at a ~60% chance of being anywhere between a 4C2R (4th cousins 2x removed) to as distant as 8C (8th cousins) - there are other scenarios such as 3C3R, 6C2R, or 7C1R. We would have to triangulate using everyone's results and family trees to be able to start to figure out and narrow down from where exactly we match. 

Chromosome 7 Comparisons [Personal Photo]

Taking a look at Chromosome 7 for my Puerto Rican cousins, you can see that they also inherited the Congolese DNA in that area as well.

Puerto Rican Cousin #1 [23andme]

Puerto Rican Cousin #2 [23andme]

African American Cousins

These two cousins have roots in the South and towards the mid-West respectively which makes it a bit harder to say exactly where they might match me since they don't overlap in similar states. However, these are probably recent states of residence and going further back might show an overlap in family both being from a certain state in the south, for example.  A look at their Chromosome 7 shows one cousin with "Broadly West African" and another with Congolese DNA in that general area. It is possible that they might have other cousins themselves tested who can help narrow down which side of the family I would match them on. 

African American Cousin #1 [23andme]

African American Cousin #2 [23andme]

You can also see that there is no European DNA in those areas for both cousins which would mean that our match is likely through an either mixed ancestor or ancestor directly from Africa. It is kind of amazing to see that amongst these 10 people, 9 of us have a classified Congolese DNA piece there. 

Many slave ships made their way first to the Caribbean and later made their way to either North or South America. It is very possible that along one of those routes a slave or various slaves were left in Puerto Rico and another, genetically related either as a parent, sibling, cousin, etc., was brought to the south in the United States. Take a look at "The African-American Migration Story" from PBS to learn more about the journey from Africa to the Americas. There are many sources that talk about the transportation of slaves to the New World, the various journeys taken, and the various stops the slave ships made. 

"Lehrbuch der Weltgeschichte oder Die Geschichte der Menschheit", William Rednbacher, 1890 [Wikipedia]

Further Research

I was both surprised and not surprised when I came across these DNA segments. For starters, I knew there were slaves in my family which was not surprising, but to be able to narrow it down to a Congolese segment inherited through various family members and traced back to my grandmother and shared by two African Americans was surprising. It's interesting to see how much can be discovered with the advent of genetic genealogy - these types of discoveries were only considered dreams back in the days. I'm lucky to live in a time where this type of genealogical work can be completed. 

My next step would be to try and figure out how we are related, though this task is quiet a big one. I have reached out to these cousins and have already started conversations with one, who equally was surprised to see our match. It might be easier to see how these two cousins are related and see how I am related to the other Puerto Rican cousins and then go from there. Though seeing as how these matches are through an ancestor from Africa, it is possible that we might not, at least for now, know exactly how we are related. 

The fact that we have been able to get this far has been nothing short of amazing!