“Ten thousand matches and only 10 of them have trees!”
“Why do people spend money on a DNA test if they’re not interested in genealogy?”
“I only test at Company X because the people at Company Y just want their ethnicity estimates. What good are they to me without trees?”
We hear these complaints all the time. All. The. Time. But are they reasonable? Personally, I’ve made some important discoveries in both my own research and for my clients using matches without trees, but that’s hard to quantify. What we can quantify, though, is the percentage of DNA matches who have trees associated with their results.
First, how do you know if a DNA match has an associated tree? It’s different at each company. The matches at Family Tree DNA (FTDNA) have a small tree icon near their names; the icon is blue if they have a tree in their account.
At AncestryDNA, you can not only see at a glance whether a tree is linked, but also how many people it contains.
23andMe makes the tree harder to find. For each match, you need to click on their name in your list of DNA Relatives, then scroll to the bottom of the next page. If they have a tree, you’ll see something like this:
GEDmatch users may also have associated trees. If so, they will have an entry in the GED/Wikitree column in the One-to-Many tool’s results.
(MyHeritage users can also link trees to their DNA results, but I didn’t include them in this analysis because I don’t have access to enough accounts there.)
What Percentage of Matches at Each Company Has Trees?
To answer this question, I looked at the DNA results of 12 unrelated people who are in the following four databases: AncestryDNA, Family Tree DNA, 23andMe, and GEDmatch. Because all 12 people were in all four databases, the possibility that one database is better for a particular group of people is minimized. Most were American, of European, African, Mexican, and Ashkenazi heritage, and one was Scottish.
For each person at each site, I determined the ratio of matches with trees to the total number of matches. (See below for details.) For FTDNA, 23andMe, and GEDmatch, the total percentage of matches with trees was straightforward to determine. However, at AncestryDNA, an account can have a tree that isn’t necessarily “linked” to the DNA (meaning the user has associated the DNA test with a specific person in the tree). At AncestryDNA, I first determined the percentage of all matches with linked trees, then I looked only at the ones saying “No family tree” (see screenshot above) to see how many did in fact have a tree that was unlinked. Finally, I used the two figures to calculate the total percentage of matches at AncestryDNA with trees (linked + unlinked).
Here are the results.
The differences were stark. And consistent. For every one of the 12 people, the rank order of matches with trees was AncestryDNA > FTDNA > GEDmatch > 23andMe. That rank order applies even if I only consider the linked trees at AncestryDNA and not the unlinked ones. What’s more, the lowest percentage at AncestryDNA (42.8%) was higher than the highest percentage at FTDNA (42.1%) and the same applies for FTDNA over GEDmatch and GEDmatch over 23andMe.
I was surprised at how few people at GEDmatch—only about 13%—have trees, given that it’s a specialized site that presumably attracts more dedicated genealogists. The low 5% rate at 23andMe is surely because that the company doesn’t host trees at all and makes the option to link an online tree difficult to find. (For instructions, see the end of this post.)
The great news here is how many matches do have trees: more than 75% at AncestryDNA (if you include unlinked trees) and nearly 40% at FTDNA. Although it sometimes feels like we all sitting around in the rain with half-empty glasses at Eeyore’s birthday party griping about trees, the reality is far sunnier. There is so much family history out there, just waiting for us to use it!
How I Got the Data
Here are the gory details of what I did at each site, in case you’d like to repeat the experiment yourself. If you do, please post your results in the comments!
AncestryDNA: I scanned the match list for each person using the DNAGedcom Client. The resulting csv file for a given kit lists all of its DNA matches and includes a ‘treeurl’ column that is populated only if the matching kit has a linked tree. The ratio of matches at AncestryDNA with linked trees is then:
Family Tree DNA: The DNAGedcom Client was used to scan the matches (Gather Match/ICW scan) and their trees (Gather Trees scan) for each person. I used the number of entries in the Family_Finder_Matches file and the number of unique entries in the ‘resultid’ column of the Family_Finder_Trees file as follows:
23andMe: I know of no scan that will survey all of the matches at 23andMe for those with trees. To get the percentage, I opened the profile pages for the top 100 matches for each person and checked to see whether they had a tree linked.
GEDmatch: I ran a One-to-Many analysis on each person. The percentage of matches with trees was:
How to Link a Tree to Your DNA Results at 23andMe
Log into your account and click on your name at the top right. Select Settings.
On the next page, scroll down to Privacy/Sharing and click Manage your profile.
On the Update DNA Relatives Preferences page, scroll down to Enhance your profile and click Family Tree URL. You copy and paste the web address (a.k.a., URL) from your online family tree at any of the following sites into the empty field: MyHeritage.com, Ancestry.com, Findmypast.com, FamilySearch.org, Genealogieonline.nl, Geni.com, WikiTree.com, RootsWeb.
Scroll to the bottom of the page and click the blue Update button. Now you have a family tree linked to your test results and 23andMe. Your DNA Relatives will appreciate your efforts!