In Parts 1 and 2 we walked you through the basics of DNA (How to make the most of your AncestryDNA matches: Part 1 – Getting started), of the importance of having a good tree to your 4xGGP, and how to label you AncestryDNA matches that already have hints (How to make the most of your AncestryDNA matches: Part 2 – Leveraging your strongest matches to make quicker work of your more challenging matches!). In this part, we start to do the hard work of building out DNA matches where we don’t have a matching trees, and we don’t know how they’re linked to us.

Once you have all of your hints with notes attached, look for your largest unidentified match that has a Public Tree, even if it’s unlinked. Since the tree has no hints you’ll know their tree doesn’t match yours (yet!), but the larger the amount of cM the closer your match…so the fewer relatives you’ll have to build out.

Before we dive in with our first example, here’s the first of several surprising truths about doing genealogical DNA work: you will spend most of your time doing other people’s trees. In a perfect world your DNA match built out their tree to their 4xGGP too…but you’ll find most times you won’t be so lucky!

DNA match surprise #1: You will spend most of your time making DNA matches building out other people’s trees.

Example #1: Eileen Wilson

As an example, let’s look at a match with an Unlinked Tree and 242 cM of shared DNA. Looking at the match’s Public Tree, the names don’t jump out (other than the very common “Smith”), but based on our notes, we know it’s on Michael’s Father’s Mother’s Mother’s Father’s line…which was William Arthur Smith. To confirm, we entered the cM in the DNA Painter Shared cM Project tool (Link), and the results (eliminating the ½ siblings) indicate the most likely matches are from our tester’s Grandparents or Great Grandparents.

Expanding our tree, we see that we had already identified Wallace David Smith in our tree, his wife Mabel, as the brother of William Arthur Smith. We also had their daughter Lula, which all of which sync’s up with the match’s tree. From there, it’s pretty easy to prove out that the DNA match is the daughter of George and Lula (Smith) Hopkins.

This is the same process whether the DNA match is 242 cM or 12 cM: use common matches to narrow which line the DNA likely matches you, identify the most likely target for your match through tools like the Shared cM Project charts and the “What are the odds?” tool. From there, build out the likely tree based on your estimates until you find the match. Then, you update the notes so when you find another shared match, you’ll have the info to narrow down their DNA line!

Make sure to make a note in your match, as we did in Part 2 of this series, so you’ll be able to focus in on other matches with less shared DNA later.

Let’s try one more match that’s a little further out.

Example #2: “A.G.”

The next target is going to “A.G.”, a woman that shares 26cM with the same tester as the first example. The first thing we do is review A.G.’s shared matches with us, and we see notes indicating that the match is on our tester’s Father’s side, so we just narrowed our focus to that ½ of the tree. Next, we went to DNA Painter Shared cM Project tool and maped out the most likely matches for the level of shared cM, which shows that it’s likely our shared match is around a 4^th Cousin, Once removed or a 5^th Cousin. This means, it’s most likely we’re looking for 3x/4x GGP as our MRCA.

The good news is that we have a strong tree to 3x/4x GGP’s for our tester. The bad news is, we have no tree for A.G. and we’re going to have to build hers out to understand where we match. We followed our own instructions on building out a “quick and dirty” Ancestry tree (Building a good Public Ancestry.com tree – Part One: sources, citations, facts, and proof), especially paying attention to find proof of relationships between each generation. And, in the end, after about 16 hours of total work we found…nothing. No match.

Which brings us to our second of our surprising truths about doing genealogical DNA work: Your DNA matches will mostly be on family lines you already have great information on, and conversely most of your unlinked DNA matches will be on family lines which are already your brickwalls.

DNA match surprise #2: Your DNA matches will mostly be on family lines you already have great information on, and conversely most of your unlinked DNA matches will be on family lines which are already your brickwalls.

In this case, we have limitations on several key areas of our family tree. Our tester is Michael’s grandmother, and on her paternal line we run into a pretty solid brickwall at her 2x GGP. They likely were born in either New Hampshire or Vermont, before they migrated to Michigan through New York, but 3 generations of family historians haven’t gotten past Alvin Jewell (1830-1911). In A.G.’s line, there are two couples from Vermont, from about that time, but there’s not enough evidence to pursue a solid line of inquiry.

This brings us to of our third surprising truths about doing genealogical DNA work:  Even with the best of trees, and hours of effort, you’re going to have a lot of matches that you’re not going to be able to link to your tree.

DNA match surprise #3: Even with the best of trees, and hours of effort, you’re going to have a lot of matches that you’re not going to be able to link to your tree.

This is also where the limitations of AncestryDNA start to become apparent. There are nearly no tools there to help us determine which side of our match’s line do we expect we match. How can we leverage DNA triangulation to further narrow down where we should be researching? When you’re trying to figure out where to look amongst 32 GGP’s who might be a key to your DNA match, being able to eliminate ½ of those potential matches is a huge boon. But, beyond what we’ve already gone through, there’s not much more they can offer.

One of the other limitations of AncestryDNA is that you can never prove your matches. Even in our first example, we have a good tree match, and the amount of shared DNA (242 cM) matches exactly where we’d expect the two samples to match (2nd Cousins), but without tools like a chromosome browser, it’s impossible to prove those two kits match as we’ve assumed.

We’ll be looking at other tools in later installments, including how we can narrow down the search for our MCRA link to A.G.

In our next installment we’re going to go through a GREAT set of tools in GEDmatch that will demonstrate what we wish we had in Ancestry, and we’ll show you how to leverage you DNA results there to really unlock your matches.