passed down through generations, this is actually
in succeeding generations. If you still have questions about
these small segments is being divided up into an even smaller
either going to be passed on intact or it's not going to be
segment to your child and this is one of the reasons why when
So, it's the exact same seven centimorgan segment that your
you receive that exact segment intact for three generations.
to the child, to you, in essence. If we actually
words, with a seven centimorgan segment. It is more likely that
you watch this video down below? 7% is the correct,
answer your questions. Now, if you'd like to learn how DNA is
an older video I made, you can watch this video up here but if
where we have even more training and live streams to
you want to learn something else about DNA, then why don't
around seven centimorgans, it's much more likely that it's
answer your DNA questions or become an FHF extra member
DNA then consider joining us for our livestreams where we
seven centimorgan segment to the parent and that parent has
segment is very unlikely and so starting roughly at about seven
actually finding these passed down multiple generations
passed on at all than it is that it's going to be divided
generation. It's because at that point, once you're down to
we look at these small segments, we can actually see
this 7 cent a mortgage segment being passed on intact there's
intact than you are going to that segment being divided up
there's only a 7%, not 7% each but 7% total for that entire
centimorgans, you're going to have more of a chance of
up. So, that's one of the things that can happen with
group. So, 12 of the four possibilities only have a 7%
these much smaller segments being passed on. There's only a
that they get passed down from generation to generation to
multiply all of those together, what we get is 7. 4%. In other
probability of happening there's a 46%. probability of
also a 42% probability of none of that segment being passed
grandparent also has a 42% probability of passing on that
than you passing on a recombined version of that
chance of happening which leaves 93% between the other
segment. In other words, a shortened version of that
great grandparent had. That is a high likelihood of happening
there's really a 93% probability of no recombination
seven centimorgan segment to a grandparent and that
a 42% probability of passing on that seven centimorgan segment
grandparent, they have a 42% probability of passing on this
on. So, interestingly enough, if we take a look at a great
and just divide by two I round it up so each one has a 42%
two and this is where we can actually do some simple math
7% probability of any of those happening. So, any of those,
happening. In other words, all of these recombined segments,
happening. If we do the math here, what that means is
99 9999 So 7 times 99%. probability of no recombination
possibilities divided by 100 was B7% of anyone of these
by centimorgans so we could have the first little
six or a five or a four or three centimorgan segment. Now,
that far I would call them a total waste of time because
covered about the extra effort then that having to sort
is a centimorgan is a 99% probability of no recombination
possibilities but if we really expand these out, there's 14
centimorgans, triggerly above 10 centimorgans, there's very
all the first part not being passed on but the last
here green represents that segment. So, in this first
looking at this, you see that there's three possibilities and
in essence, centimorgan is one percent probability of a
happening. So, in our hypothetical seven centimorgan,
centimorgan. The definition of a centimorgan is little
on recombined. In other words, it becomes an E smaller
It's not 33%. So let's look at this a different way. We have
possibilities. Remember, I said before, there was three
chance of anyone of these happening and you'd be wrong.
you might be thinking, okay, well, there's you know, a 33%
fruitful the other 32 hours were really totally wasted so I
what can possibly happen with this small segment? Well,
look through 33 of these false segments to find one true
centimorgan of that being passed on so here's all the
on to the children. Two, this small segment could be passed
there's three things. One, this small segment cannot be passed
possibilities of what could be passed on without dividing up
centamorgan of it and the rest not passed on all the way up to
false segments and if you want to know why false segments
centimorgans into half centimorgans or quarter
centimorgans and in this case, we end up with 14
the segment is not passed on at all and then the other twelve
between each one of these groups because of how they
is passed on totally intact. The next block is Y that means
go down in the size, we're going to see more and more
when you think of some of these at three centimorgans worth 97%
segment if you just assume that you're spending an hour on each
we can agree from these four different data sets that as we
what we have is we have a 99% times 99% times 99% times 99%
match you spent 33 hours only one of those hours was actually
possibilities and simple statistics of saying, well, 14
simple. So, let's go back to what a centimorgan is. So, a
looked at it, what algorithms are using, what data they're
are how that segment might be divided up if we're just going
don't want to go into that anymore here but what I want to
you're going to be running down a lot of rabbit holes. Blaine
recombination happening. So, another way of looking at that
on intact. And then three, this small segment could be passed
confusing. I have made a video about what a centimorgan is but
segment. Instead of a seven centimorgan, now it's maybe a
block that you see that totally green, that means the segment
different way and I had to extract some of this data from
is almost all of the segments you're looking at are false
only one out of thirty-three one out of 30 yeah one out of
six centimorgans, it's about 50% false segments and then we
they're finding about 15% false segments all the way down to
this channel about false segments. Now, previously, I've
three centimorgans where they're seeing as much as 70%
so some of this may not be exactly the same as what we
amount of false segments goes up rapidly. Above seven
might be bad, then, you can watch a video that we have on
happening and that would be wrong as well. It's not that
few false segments that anybody is finding and so I think that
through these false segments is to where your genealogy work,
using to be able to come up with this information. Overall
Bettinger calls these false segments poison I wouldn't go
this small segment, we'll just say at seven send morgans. So,
what I found is that obviously the trend here is the same
false segments. It's a lot of data and it's good to actually
definite trend once you hit seven centimorgans that the
you can see this trend is still it gets progressively worse in
have a nice paper like family tree DNA or a nice table like
look at is something else statistically. So, if we have
segments and it gets progressive worse as you go
is the correct number that means you're having to go and
were looking at before but I think it's close enough and
33 segments are going to be true segments a lot of matches
centimorgans are seeing about 3% false segment. Going down to
John Walden and Tim Jansen did so I had to extract some of
going to be helpful for you now with ancestry DNA they didn't
have 23 and me. They also looked at this again in a
a third or really a third of all of the segments are false
lot more false segments than what John Walden and Tim Jansen
just tables that they had but starting at six centimorgans,
data. What they found is that at around 13 centimorgans
though, one of the things that we can see is that there is a
fact their four centimorgans and three centimorgans show a
and Tim Jansen have found and that goes up to about 2% at 10
at seven it's only 10% as opposed to the 33% but there
segments which is very comparable to what John Walden
that's our first data set now family treaty DNA just recently
look at it all together. Now, there's obviously variability
again at 13 centimorgans they find about 1% are false
in order to accomplish this and some of them define things a
they have to identify what they consider percentage wise what a
false segment a false segment and then using the information
little bit different ways. What I've tried to do with this is
came out with a white paper that explained some of their
methodology and they had a similar table with would you
this from some different graphs they had with the explanations
down from there to the point where at three centimorgans
to go through to be able to find different things that are
guess actually somewhat similar although varied a bit results
low but by the time you get to seven centimorgans it's almost
at 10 centimorgans it's only about 4%, which is still really
Jansen. So we'll just call this John Walden and Tim Jansen's
actually find on the ISOG Wiki. And this was from John Walden.
found in fact at three centimorgans 97%. I mean that
there's really no false segments. But as you
progressively lower than that false segment start to increase
false segment is. So let me start with a table that you
definition, let's go and let's take a at some data. Now, I
calculate this. Some of them are using different data sets
you're looking at 89% of those segments are false segment so
I've tried to basically simplify it down into calling a
happens in these really small centimorgans. With that
match is if you have that match and neither one of your parents
Uh some research that he did that was reported to Tim
about small segments is that this is where the probability
their information. They have different algorithms to
in fact, none of them are using the same method to come up with
went through and I found four data sets. Not all of them are,
a real match. Now, I'm not going to go into everything
of false match begins to be larger than the probability of
has that match then it's a false match and that usually
about a false match today. One thing to look at for a false
think agree is where the small segment start the exact point
where they all start we don't agree but somewhere between
use less than about seven centimorgans. The other thing
may say it's less than six but somewhere around there we all I
sentence some people may say it's less than 10 some people
field in a lot of cases these things are somewhat fluid and
there because I'm using less than and about in the same
about seven centimorgans which seems a little bit meely mouth
this you know five to 10 small segment start so I'm just to
segments can actually be used for genetic genealogy. So, let
start with a definition of hey, a small segment is less than
me start by going with a basic question. What is a small
looking at small segments and whether or not these small
there may not be a exact definition. So, I'm going to
segment to begin with? How is it really defining with any new
that are going on between about whether or not they should be
you climb your family tree and have fun along the way. Small
segments happen in DNA and if you go on to Facebook in any of
the genetic genealogy groups, you're going to find debates
not we should even be looking at them. So, let me try to
welcome to Family History Fanatics where we love helping
tackle a couple of issues with small segments today. Howdy, genealogy riled up, it is about small segments and whether or
If there's one debate that seems to get different genetic
sorry, is past or sorry. Okay, my nose is itching.