Wednesday, February 3, 2021

Painting My Ancestral Chromosome Map - Post #1

 I have been lax in painting my Chromosome Map on DNA Painter, and made it a genealogy goal for 2020, which I miserably failed.  So I made it a 2021 goal, and have now done as much as I can at this time.

I want to share my results and be a good example for readers who might be considering doing this.  Please understand that I am NOT an expert at DNA testing and analysis, but I love to extend my knowledge and capabilities.  If I can do it, you probably can do it too.

1)  Making a Chromosome Map on DNA Painter is really pretty easy if you have enough DNA matches with known common ancestors (or can figure out the known common ancestors) on MyHeritageDNA, 23andMe, FamilyTreeDNA, and GEDmatch.  

If you only have AncestryDNA matches, then you are out of luck because AncestryDNA does not provide a chromosome browser, and does not provide chromosome segment definitions for your DNA matches, much to the dismay of every AncestryDNA customer who is a genealogist.  If they did, with the 400+ DNA matches with known "Common Ancestors" that I currently have on AncestryDNA, my Chromosome Map would probably be fairly complete.

It helps to understand the chromosome browsers on the DNA services, because that is where you can download the DNA segments from a specific DNA match to a .csv file (the start of a spreadsheet file).  You can then copy the DNA segment information from the spreadsheet into DNA Painter, answer a few questions about the known relationship, and DNA Painter "paints" that segment onto your chromosome representation.  

Several genealogy bloggers who specialize in DNA analysis have written blog posts about the process to turn the segment data into visual segments:

DNA Painter Match Data Help  and Segments by Jonny Perl on DNAPainter.

*  DNAPainter Instructions and Resources by Roberta Estes on DNAeXplained - Genetic Genealogy.

2)  DNA Painter provides the Chromosome Map for FREE for one Map on their website under Chromosome Maps for account holders.

Here is my DNA Painter home page:

3)  Since I have made a chromosome map, it shows me my status.  When I click on the link for my name, I can see my painted Chromosome Map (two screens):

My 23 chromosomes are listed on the left.  Each chromosome has two lines (except my X) - the light blue line is from my father, the light pink line is from my mother.  I only received my X chromosome from my mother because I am male.

All of the other colors are from my DNA matches for whom I have known common ancestors.  The color key on the bottom right shows a different color for the known common ancestors of my DNA matches and myself.  For instance, the bottom common ancestors with the purple color are my grandparents, Frederick W. Seaver and Alma Bessie Richmond, who are my father's parents.  

I don't have any known DNA matches on my mother's side until I get back to the Kemp/Sovereen 2nd great-grandparents. I have segments for the Carringer/Feather, Spangler/King and Vaux/Underhill 3rd great-grandparents.  My mother was an only child, her parents were only children, and I have no DNA matches on any service who have one of my maternal great-grandparents in their ancestry.  I do have several DNA matches on AncestryDNA who descend from my maternal 2nd great-grandparents but I don't have DNA segments from AncestryDNa and they are not on the other services.

In some cases, I have been able to find AncestryDNA matches with known common ancestors (from research or ThruLines) on the services with a chromosome browser and have used them.

The bottom line is that I have painted chromosome segments from 32 DNA matches, in 161 segments.  The Chromosome Map is 26% complete.  I have a long way to go! 

4)  DNA Painter provides a number of Tools, Options and Reports under the gear icon at the top of the Chromosome Map, many of which require a monthly subscription to DNA Painter.  One of the FREE reports is the "All Matches" report, shown below with the match names obscured:

The "All Segment Data" report shows the list of DNA segments, by segment, for each DNA match - I obscured the match names in the chart below:

5)  By clicking the big plus ( + ) icon next to the gear icon at the top of the chromosome map provides a magnified map of each segment on each chromosome with the names of the DNA matches, with the option to turn off the names - I did that for the chart below:

6)  You might ask what can I do next?  Well, I can try to trace the ancestry of my high DNA matches on MyHeritageDNA, FamilyTreeDNA, 23andMe, and GEDmatch using their names, any family tree information on their profiles, or information I can sleuth from online searches and records to find common ancestors.  I've done that for some DNA matches, and have been successful in finding common ancestors for 30% to 40% of them.  Then I can paint the shared segments into DNA Painter and assign them to known common ancestors.  

Only 74% of my chromosomes to go!

I exist and know about all of this because my parents created a child in about January 1943 and the magic of conception and recombination created all of the above.  

7)  Isn't technology wonderful?  Thank you to Jonny Perl for creating DNA Painter - it's like magic!  Thank you to MyHeritageDNA, 23andMe, FamilyTreeDNA and GEDmatch for providing chromosome browsers to customers and enabling the easy creation of the DNA segment files.


The URL for this post is:

Copyright (c) 2021, Randall J. Seaver

Please comment on this post on the website by clicking the URL above and then the "Comments" link at the bottom of each post.  Share it on Twitter, Facebook, or Pinterest using the icons below.  Or contact me by email at


Linda Reid said...

You might want to put the ancestors on your key with the earliest generations first, i.e. 4xgreat before 3xgreat etc. That way you will see all the segments assigned to the most distant ancestors and they won't be overlaid by segments assigned to a more recent generation.
You can easily rearrange the order by clicking on the little dots to the right of the name and dragging the listing to a different location.

Linda Reid said...

Why did you paint segments that came from a set of grandparents? That's the same as saying that the DNA came from one parent-- and that is a given.