Triangulation + Mapping

This is a triangulated DNA segment (courtesy of MyHeritage) that I share with a woman from Texas and her two daughters.  The red is daughter 1, the yellow is daughter 2, and the orange in the middle is their mom.  Interestingly, I share two 6cM DNA segments with daughter 1 that I do not share with the mom.  Right now I don't know if those are coincidental or if I'm also related to daughter 1's dad.

After reviewing the mom's family tree, I determined that I am her fourth cousin once removed and a fifth cousin to her two daughters.  Our shared ancestors are Joel White (c.1790-) and Rebecca Barnes (c.1795-) of Clay County, Indiana.  Her great-great-grandmother was my great-great-great-grandmother's younger sister.

Now that I've figured out how we are related, I can map this portion of Chromosome 2 on my maternal side.  I simply download the shared segments from MyHeritage into an Excel spreadsheet...

Name Match Name Chr Start Location End Location Start RSID End RSID cMs SNPs
Lisa Perry [~] 2 172429907 202693975 rs6729179 rs55852210 23.7 13824
Lisa Perry [~] 10 131054514 135523246 rs35100572 rs9665515 9.5 3455

...which I then copy and paste into DNA Painter.  I did not include the two 6cM DNA segments that I share with daughter 1, partially because they don't meet DNA Painter's default 8cM exclusion and also because I doubt that they're from the same ancestor.

My great-great-great-grandmother was Lydia Celia White (1820-1848), the daughter of Joel White and Rebecca Barnes.  At the present time, I cannot tell whether the shared DNA segment came from Joel or Rebecca, so I have assigned it to Lydia (depicted in lemon yellow below).  Anyone who shares DNA with me at that location should be related to Joel White and/or Rebecca Barnes.

 

Leave a Reply

Your email address will not be published. Required fields are marked *