Finding the most recent common ancestor is the key to identifying how you're related to your
DNA matches, and now GEDmatch has a tool that you can use to do that. Howdy, I'm Andy with
Family History Fanatics, where we help you understand your DNA, climb your family tree,
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month. Today we're talking about a new tool at GEDmatch that is called defined the MRCA from
your DNA matches. GEDmatch really started out as a Gedcom comparison tool and with the power
of DNA added to it. It can help us find matches that we should have GEDCOMs that are linked
together. By looking at the Gedcoms, we can find a most recent common ancestor. Now previously,
you had to do this yourself by going through and searching through all the different matches where
each GEDCOM matched in order to find a common ancestor. Well, now you can do that with this new
tool, but there's a few things that you need to do beforehand. So one of the first things that you
need to do is you need to make sure that you have a GEDCOM file uploaded to GEDmatch. If you don't,
there's nothing to compare because this is not just looking at you and your DNA matches, but it's
also looking at your GEDCOM file compared to your DNA matches GEDCOM files. So if nobody uploads a
GEDCOM file, then you're not gonna be able to compare them, but if everybody uploads a GEDCOM
file, then there's gonna be lots of information to compare. So if you haven't uploaded a gedcom
file yet, then go ahead and do that now. Now the next thing that you're going to want is you're
going to want to link a person whose DNA has been tested to the GEDCOM file. Now, in this case,
it's usually going to be yourself, or it may be a close relative, a parent, or a grandparent. If you
have that DNA tested by doing this, what we've done is we've created a definite link between a
match and our gedcom file. So now the computer system can go through, and it can try to match
up where those gedcom files meet. So let's go over to GEDmatch and see how this tool is going
to work. So here is the tool, and it's going to be very simple. All we need is we need a kit number.
I'm going to use my grandfather's kit number for this because his is the one that I use most often
in my research. Now there's a few presets that you can use, and right. now we're gonna start
with just looking at this with this all at what is present. You can change the number of kits
that you're considering looking at. You can change the minimum amount of centimorgans to be comparing
to. And you can change the match score. Now more on that in just a moment, but once you're ready,
click on submit, and you're going to start to see how some of these gedcom files might identify a
most recent common ancestor depending on how many matches you have that have Jed compiles.
This process may take several minutes, so don't be worried when just one or two lines pop up,
and it's taking a while for other things to pop up. The program is still working,
and it's going to get there in just a moment, but this is the list of people that are potential,
and I say that again potential, most recent common ancestors, so let's go through this list and see
what kind of information that we have. We start with the kit number and the name of our match.
Next, we have the amount of centimorgans that is in that match, and this is all sorted from the
largest down to the smallest. Next, we have the name in our gedcom kit of who that match is, and
you'll notice that in our matches gedcom kit right here, it should be the same name or roughly the
same name based on the matching algorithm. Then it also tells us how far away we are from that kit,
and it tells us how far away our match is from that kit how many generations then. There's a link
to the actual path upwards and downwards, and then there is the comparison of the two gedcom kits as
well as a link to the gedcom and the person within that. So let's explore this further by
going through each of these links and seeing what they're actually showing. I'm gonna start with our
person. This is the person page for that most recent common ancestor that I would see in my
gedcom file. Now there is another link there which is going to show it and the other person's gedcom
file. Previously I went over the different uses of the gedcom matching within GEDmatch, and you can
see that this information is basically telling us who the parents are, who spouses who the children
are with some basic names and birthdates. And you can click on any one of these names to be able to
go to that person. If you want to research that a little bit more so that link really covers this
primary person and it also covers what we would see from our matches gedcom file, we can actually
open both those up and compare them together to see if some of the information matches more
directly or give us a clue as to whether or not this really is a most recent common ancestor. So
the next thing we want to do is we want to look at the descendency path to ourselves, which also
is going to be similar to this descendancy path to our matches. Here this link goes right to a
descendancy path, and it starts from the most recent common ancestor up at the top here all
the way down to whichever generation is going to be your match. In this case, it is Burton Lee,
my grandfather. You can also see there that there is a little DNA symbol showing that yeah,
that person does have DNA and if there was any of these other people in this list that had DNA
also on them. Then there would be that symbol as well. So these two links are going to this
descendancy chart. So that gives us the links to the descendancy path, and now we actually want to
look at this path, and this is actually probably one of the most useful parts of this tool. So on
this descendancy path, what we have is we have the tendency to us, and we have the descendants to our
match. And they're lined up by each generation. So that you can actually see from the most recent
common ancestor all the way down to you and your match how that path goes. Now, in this case,
as I'm looking at this, I can actually see right off that these two are probably not the same
person. My main clue is that this Jane Gordon that my grandfather is related to was born in Kentucky
in the United States. Whereas this Jane Gordon was born in Sutherland and then also you can see
their descendants were all in New Zealand. Now, if they're, it's possible that these are the same
person if there is some errors in the research that either my match is done or that I have done
but based on what I already know, this is probably not going to be a most recent common ancestor and
where we can start to be looking is we can also be starting to look at this match score. What
does this mean? well, the algorithm is looking at lots of different things as far as the name,
the birthday, the birthplaces, to come up with a score as to how likely this is a most recent
common ancestor or how likely these two people are the same people. In this case, the match score of
two and then we want a higher match score of 10 is a perfect score. So a 2 is relatively low,
so it's not surprising that this one didn't turn out to be a most recent common ancestor. So Path
1 is going to give us a nice side-by-side comparison of our pathway to our most recent
common ancestor as well as the match's most recent common ancestor. But going back here, we can see
on the score column here we can actually use this to help investigate. And so, for instance,
I already said that this too is not going to be a most recent common ancestor in this case because
it just doesn't even match the right amount of information. On the other hand, when I'm looking
down this list, I see, hey, there's this six right here. There is an eight right here that's probably
a really good indication that they're the same person. And I'm seeing a lot more of these twos,
maybe even some threes in that. And so each one of these, I'm going to want to be a little bit more
spectacle as I'm looking at the twos to make sure that the information is exact or that the research
is more correct rather than just assuming that this is the right person. But let's go back and
look at what the compare gedcom x' does. Now the compare gedcom x' just takes us over here to the
compare gedcom x' tool where we put in our gedcom number, and we put in the other gedcom number.
In this case, it's already even populated by the computer system and then clicking on the compare.
You can actually see all the people that match not just the most recent common ancestor but all
the people in this gedcom who match each other. So we've done the comparison of the GEDcomps,
and finally is the gedcom ID. And this is just a link to that person in this file. So if I click on
that then I'm going to go over here and find this match. Now you'll notice here on this match that
they have their parents listed. They have who they're married to and any children and in this
case, they've been anonymized because these people are still living, but this also gives me links
directly into that gedcom that I can see other people in that gedcom file. Now that I've gone
through what each one of those links on this page does let's go and see what changing some of the
default settings is going to do. Now, in general, if you can take a look here, I have 24 most recent
common ancestor potentials down, and I just want to emphasize that these are potentials. You still
need to go through and do research to verify or validate whether or not these are the correct most
recent common ancestor with you and that match. So I have 24, and this comparison looks like it
took about four minutes to actually run the whole thing going back to the start of the tool. I'm
going to actually change the minimum centimorgans up to twelve centimorgans, so the default is seven
centimorgans. So I'm gonna go up to twelve centimorgans take out all those matches that
match less than twelve centimorgans. And here is the result if we scroll down, we can see that hey,
there's a lot of the same people, although once we get down at the bottom, all those bottom ones
are not there. Because this is only found 14 most recent common ancestors because it's only looking
for those that share at least twelve centimorgans or more likewise you can see hey this only took 67
seconds just a little over a minute in order to run because there's a lot less information it's
trying to process. One of the other things that you can do is you can change the minimum match
score. Now GEDmatch actually recommends that you change this up to at least a three or greater in
order to filter out any of those false matches. Now I showed you an example already where I had
a match that we matched 0.35 centimorgans. We had the same name, but from the birth date and
the birthplace, it looks like this was not a most recent common ancestor, and they only had a match
score of two. So by doing with a match score of three or above, you're going to limit the
number of people that are shown. But these will be much more likely to be the most recent common
ancestors. In other words, the information that is shared in both GEDCOM files is much more similar.
So here is my run, and this is with a minimum of seven centimorgans but a match score of three.
You can see that the Jane Gordon is not the first one. It's now this Jane May. And all of the twos
that I had are gone. In fact, we're down from 24 to just 18 of these are a grade three or higher.
So this is one way that you can limit it if you end up having a lot of matches in this area. Now,
this is based on the number of your matches that have GEDCOM files attached to them. So as more
people add GEDCOM information into the GEDmatch database, you're going to see more and more
matches on this list. So I hope that explanation of the finding the most recent common ancestor
with your DNA matches is helpful in getting you started in using this tool to really streamline
some of your research. You can do this with some of the other tools on GEDmatch, but you
have to sort through a lot of matches between two GEDCOM files. This tool makes it really easy. So
that you can just put in the GEDCOM file of your match. It's going to search through all of the
GEDCOM files of the other matches and identify the potential most recent common ancestor, and
that can get you started on doing more research to verify whether or not that most recent common
ancestor is the most recent common ancestor of you and your match. Do you have any questions on how
to use this tool, then put it in the comments below, and I'll try to answer it for you.