With Mother's day being this Sunday here in the United States, I decided to take a different and closer look at my DNA - I wanted to see how my X-Chromosome and those of my grandmother, grandfather, and great-grandfather were passed down; all exclusively inherited from my maternal side of the family. Since I am fortunate to have these members tested on 23andMe, I can visually see how this inheritance how trickled down via 4 generations.
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| X-Chromosome Inheritance [Personal Photo] |
Above you can see how I get my X-DNA through various generations and ultimately down to me. Having used DNAPainter (I've posted about it before) to trace my matches I have been able to trace which segments belong to which ancestors along potential my X-chromosome inheritance ancestors. It is important to note that as a male I have one X-chromosome inherited from my mother BUT from various ancestors including my BOTH maternal grandparents, both great-grandmothers, one great-grandfather, etc. This is demonstrated below:
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| X-DNA Male Inheritance [The Genetic Genealogist] |
This would mean that by understanding which pieces of DNA came from which sets of ancestors I could have a better idea of part of their cultural inheritance passed down to me via my X-chromosome.
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| My X-Chromosome Inheritance [Personal Photo] |
You can see above that mainly my maternal grandmother's DNA is the one I carry while my maternal grandfather's DNA "bookends" my grandmother's genes. Looking at my ancestors that have contributed to my X-Chromosome, I can start to unravel a bit of a story for my ancestors. It's also important to note that various siblings can inherit in similar but different patterns a X-chromosome, so while I may have a smaller amount of my grandfather's DNA my brother's may have inherited different segment start and end points along their X-Chromosome.
Genetic Breakdown
North African & Arabian; Broadly European
These two pieces of DNA here were inherited from my maternal grandfather's ancestors. I'm not sure from which specific ancestors these are from yet but these ancestors were from the areas of Toa Alta and Barranquitas/Morovis in Puerto Rico. The Toa Alta side includes surnames such as Santos and Chéverez while the Barranquitas/Morovis side includes Rivera and Rodríguez - these are the surnames from 7 generations back of my 4th great-grandparents.
Native American
The first Native American chunk seems to come from my maternal grandmother while the second Native American piece of DNA is from my maternal grandfather. Interestingly on the first native segment I have two matches from my dad's side of the family that match me on my X-chromosome. This would mean that somewhere along my 2nd-great-grandmother's line there is a shared ancestor that comes from my great-grandfather, to my grandmother, and to me who is tied to my paternal Rivera side.
Surnames on the first Native DNA segment include Arvelo, Flores, Sánchez, Vera and were from the area of Quebradillas and San Sebastián in the 1700-1800s. The second DNA segment include the same ancestors from the previous "North African & Arabian; Broadly European" which where ancestors from the areas of Toa Alta and Barranquitas/Morovis. The Toa Alta side includes surnames such as Santos and Chéverez while the Barranquitas/Morovis side includes Rivera and Rodríguez.
Broadly Southern European; Spanish & Portuguese
This whole blue segment basically comes from my grandmother. The beginning broadly Southern European segment I think is tied to my great-grandfather while the Spanish & Portuguese I think is tied to my great-grandmother. Deducing that, that would mean that the Spanish and Portuguese DNA is mainly from my Maunabo and Yabucoa side of the family. Surnames on this side of the family include Burgos, Dávila, Orozco, Ramos, Ruiz, and Santiago. These family branches have been in this area for hundreds of years with some lines stretching back to Las Piedras and Humacao back in the 1700s. It be interesting to try and see if I can find more matches to try and parse down genealogically which of these Spanish & Portuguese segments are attributed to whom. Having recently discovered my Dávila line from Spain it would interested in seeing which of these segments could potentially come from that family. Also, these ancestors were mixed between identifying as "white" and "pardo" so it's interesting that such a big chunk is specific to Europe - it makes me wonder if it's specifically from a certain set of white ancestors.
Conclusion
Studying my X-Chromosome has only given me a look into certain ancestors along my family tree. The more matches I have on my X, the better I will be at trying to triangulate which ancestors contributed to those segments and understanding their mixes. Of course, autosomal DNA and matching on other non-X-chromosomes is helpful as well but it's interesting to see that certain ancestors carried for example North African DNA to Puerto Rico and potentially those ancestors also contributed North African DNA to other chromosomes in my DNA as well. It's also amazing to see how the colors showcase the diversity of my family as well.
