Review – DNA Painter

Tech Tuesday
By Don Taylor

Last fall, Blaine Bettinger mentioned in his Facebook group, “Genetic Genealogy Tips & Techniques” an introduction video was available on YouTube for DNA Painter. I respect Blaine’s opinions, so I knew that I wanted to give it a try. It took a while for me to get to it and I’m glad I finally did. Wow, great program.

DNA Painter helps you understand exactly where your DNA came from. With it you can determine if a segment of your DNA you have may have come from your great grandmother on your maternal grandmother’s side or from another ancestor.  You can paint with common DNA information from GEDMatch, Family Finder (Family Tree DNA), or 23&Me. Sadly, Ancestry doesn’t provide DNA segment matching data, so it can’t be used. However, the raw data from Ancestry may be exported by the DNA owner and then imported into GEDMatch or Family Finder where you may export the data for use in DNA Painter.

The DNA Painter video was great. I only needed to watch it once and I was confident I understood the tool enough to use it for DNA painting. I was right; the tool is very easy to use.

I am fortunate because I have had my mother tested and I have her results. So, if my mother has a DNA Segment and I have it, I know it came from her. All the other DNA that I received from my biological father, who passed away before autosomal DNA testing became available.

I began doing the DNA painting, copying the data about matching segments of DNA from various cousins. When I looked at the matches from my half-aunt and myself, I could see exactly which DNA segments came from my maternal grandfather (and his ancestors). I compared with a known third cousin and saw which DNA came from our common second great-grandparents.

Note: Chromosome 3 (top line) has a long DNA segment known to be from Hugh Eugene Roberts

Note: Chromosome 3 (top line) has two DNA segments (in pink) known to be from Asa Roberts and one segment from an unknown Ancestor, not Asa.

I could see where bits of DNA came from.  In another example, I received a nice 141cM chunk of DNA from my father on Chromosome 3. Based upon other DNA matches, of that fragment of DNA a 21cM piece of it and another 17cM piece of was inherited from Asa Roberts. He also had a sizeable 47cM chunk of DNA inherited from another ancestor that apparently was not Asa. I don’t know who it was yet, but additional samples should show its source. It was fun to do, but I couldn’t see a substantial genealogical reason for doing it. How could I use this tool?

DNA Painter shows three DNA segments match on C. 13 for Glennis.

Then, I thought about my half-sister Glennis, so I started a new profile and began painting her DNA. We share a common mother, so, once again, I was able to copy that information into her profile and have all of her maternal DNA. Then, I could focus entirely on her unknown paternal side.  I began finding any of her biological cousins that do not contain our mom’s DNA. That is when I started to see a pattern.  There were segments that were shared by a common ancestor of multiple individuals. That proved, to me, that these segments were from a common ancestor. Their trees indicated that they shared a known ancestor, so I know that Glennis shares either the same common ancestor or an ancestor of that individual. Furthermore, if the individual is more genetically distant than a second cousin, I know that the descendants below the person’s second great-grandparent cannot be a direct line. That can save me considerable research disproving a potential family line.

DNA Painter is a great tool that can help identify likely genetic ancestors and help identify unlikely descendant lines. I like it.