Monday, August 22, 2016

Puerto Rican DNA Crumbs

Every time I search my DNA matches, I'm overwhelmed by Puerto Rican results which makes sense right! Well, it does… in a sense. Since my family is from Puerto Rico and has been since at least the 1700s/1600s, easily it makes sense that most of my DNA matches come from Puerto Rico. Though at the same time, I have seen others say that though are 1/2 or even 1/4 Puerto Rican, their results are overwhelmed with Puerto Rican matches, which genetically shouldn't be. However, this is frequently explained by the "founder effect" that has occurred on the island, since many arrived early on and then whether on purpose or by mistake, married into their families through close and distant cousins thus causing DNA to be recycled through various generations of contact. I've mentioned before that my own parents are cousins, and not because they wanted to be but because their families through time moved around the island and then my parents had no idea they were related 4-5 generations back.

However, I occasionally find what I call "DNA crumbs", small pieces or fragments of DNA that may point to other origins outside of Puerto Rico somewhere further back in my tree. For example, I have received two cousins that were particular interest to me - one with ancestry in Angola and the other in Zimbabwe which tells me that my ancestors, specifically my slave ancestors, might have been from those regions themselves. What's even more interesting is when these DNA fragments also match other people in my list of DNA cousins that also aren't Puerto Rican!

For example, I have been able to find a cousin who matches me exclusively through my maternal side. Though he doesn't not match my mother, he does match my maternal uncle, my maternal grandfather, and even my maternal great grandfather, therefore my mother did not receive this specific piece of DNA. This cousin is mainly descendant from Ashkenazi Jews and it definitely show in his DNA. So I wanted to see if where we matched had any pieces of Ashkenazi traces. The chromosome in question was Chromosome 12.

Taking a look at my own Chromosome 12 I could tell that I had no Jewish DNA there, and neither did my mother.

Chromosome 12- Luis [23andMe]

However, when I checked my family members who matched this cousin I noticed that they all had inherited this piece of DNA, and all in the exact same spot!

Ashkenazi DNA Chromosome 12 [23andMe]

As you can see, this cousin has ancestry mainly from Ukraine and Poland while my family comes from Puerto Rico. That same piece that my great grandfather had my grandmother inherited and passed it to her son but not her daughter. Below you can see how this cousin compares to the maternal members of my family.

Cousin #4 vs. Maternal Family [23andMe]

Though I'm not sure where this DNA came from exactly in my family, I'm not surprised to see I have Jewish ancestry. My historical guess would be that this match has a Sephardic Jewish ancestor who traveled to this region and was absorbed by the local Ashkenazi Jewish community there, just a guess of course based on what I know about my own family's countries' of origin histories.

When I started digging a bit further I started finding some more interesting things, also dealing with Jewish cousins! I had noticed that I had a match who 96% Ashkenazi Jewish, another cousin 95%, and one with 50% Jewish DNA. All of these cousins where from European countries (all three different areas) and none had ties to the Caribbean. Individually I had compared them to my family and then I had an idea -- could they match each other?! And I was astonished when they did! When I compared them in Ancestry Tools > Family Inheritance: Advanced, I noticed that not only were they matching my family on Chromosome #1, they were also matching each other! Even more interesting is that two of these cousins have full Ashkenazi Chromosomes but none of my family members have Ashkenazi DNA there, just an European segment that is common amongst all three. Not sure how to genetically explain that, though! 

And then something else more interesting happened, I noticed that each had the surname Ross (or a variation of the name: Rosenberg, Rosen, etc.) in their list! Below you can see how these cousins match my family, this time the segment was received by both my mother and maternal uncle by their father, my maternal grandfather. 

Chromosome 1 Comparisons [23andMe]

Of course, the connection of the surname "Ross" could be a coincidence, but I thought it was interesting that these cousins not only matched each other and my family but also had this surname associated to them as well. Not sure that I would ever be able to find this connection and/or triangulate how I am related to them but I think it's interesting that DNA does allow this sort of analysis.

I'm hoping that as genetic research keeps advancing and more people continue to test, I will be able to match more Puerto Ricans who can confirm my connection to them on their tree. Also, thinking about testing more cousins to see if I can divide up how I have done with these cousins to find where these matches originate from down my tree. Time will tell! 

1 comment:

  1. I still struggle with understanding the whole DNA thing. Reading this post makes me want to learn more & understand my results better. Thank you for the push.