A gedcom is a software tool that allows a person to build, save, and share family trees. There are loads of free gedcom software online you can download to your computer.
Before I added this information I used Excel to create a single DNA Workbook using Gedmatch Tier 1 tools which I keep on my desktop. Within the workbook I have downloaded on separate sheets: Tier 1 Beta Graphic Tree, Graphic Bar Chart, CSV file, Triangulated Segments and Matching Segments. I recently added a sheet for Gedcom + DNA Matches. I have two other people I have shared this method with who are also getting great results.
I recommend this for everyone; especially people who are adopted and looking for biological family. If you are building a Mirror Tree, it all starts with finding your most recent common ancestors and this works.
GEDmatch: Gedcom + DNA Matches
An often overlooked tool on GEDmatch is the Gedcom + DNA. You will find it on your landing page.
When you enter your kit number it will bring up everyone who is a DNA match to you and has a tree on GEDmatch. Yes, you can view these people on your one-to-many page, however, sometimes it's nice to have a separate page just for gedcom matches in a spreadsheet in your workbook. Add a column in the spreadsheet for notes. It also gives you a ready place to find all gedcom user numbers. (Recommended)
To find gecom ID numbers; enter the kit number in User Look Up which is also on your landing page.
You can enter any two gedcom ID numbers (not kit numbers) into the 2 GEDCOMs tool and it will search both trees for you. (This tool is what made GEDmatch so popular in the first place.) No more crossed eyes from studying trees.
|Click on 2 Gedcoms to open this window. Enter gedcom numbers and click Compare.|
This tool comes up with the same, or similar names, and you review the information to decide if these are a match. You don't have to click on anything else unless you are certain you want to confirm the match. (Hint: if you get similar names in the same geographic area and time frame, and with no parents listed, these could be siblings or cousins. If they have the same parents...BINGO!)
Added Power in GEDmatch
Compare gedcoms in your Gedcom + DNA list with trees in your Triangulated Graphic Tree in Tier 1 Beta tools. They are the matches who have a little green tree in the rectangle. Bold all of those matches that are in your Gedcom + DNA who are in your Triangulated Graphic Tree.
|Kit number at top of rectangle. Green tree indicates a tree associated with kit. If you are live on Tier 1 you can click on tree and review. You need gedcom number to do a compare. (See above to look them up.)|
Some of the DNA matches you have in the Gedcom + DNA list may not have had enough DNA show up in your triangulated groups; therefore you need to compare the Gedcom + DNA that are not bolded against gecoms of people in your triangulated groups.
Even though their segments may be smaller, if three not too closely related people, share the same position, on the same chromosome and have the same common ancestor in their tree, it makes a triangulated group.
AND, if another person shares that same ancestor, but in a different location on a different chromosome, it adds another layer of verification for that shared common ancestor.
You need at least three people (you count as one of them) to verify the common ancestor on a different chromosome. IMPORTANT! This piece of DNA in a different location could be a different common ancestor AND THIS COMMON ANCESTOR WILL BE FROM THE SAME LINE OF ASCENT OR DESCENT FOR YOU.
For adoptees, you are actually doing "reverse" tree building. You will use the triangulated Most Recent Common Ancestor (MRCA) to find the MRCA you are looking for and following the branches down to you.
(I consider blog shares a genealogical blessing.)