WADE surname DNA project Using DNA to find your ancestors
Most
of you are researching your Wade ancestors -- trying to document at least one
more generation back in the chain or trying to find the descendants of a
particular person. In some cases the question is as simple as "are
these two persons related?" The difficulty is getting past brick walls
created by lost, burned or never-existing records of births, deaths, marriages,
etc., and conflicting info in documents. Hopefully our DNA project will help you get past your brick wall.
How can that happen?
The
simple answer is for you to find a match between your Wade DNA and that of
another Wade family who has a documented family tree that precedes your own
documented tree or has information about descendants that you do not have. Then you can focus on the missing link between your
family and the family with matching DNA. The DNA results will not tell you
who links your tree and that of the family with matching DNA, but it will tell
you that your families have a common Wade male ancestor -- what geneticists call
the Most Recent Common Ancestor (MRCA or TMRCA).
Table 1
below shows the accuracy of various test markers in determining the number of
generations back for a MRCA for two related individuals. If two people who
participate in the project have 12 of 12 markers that are identical (match
exactly), then their MRCA is less than 14.4 generations back for them 50% of the
time or 288 years on average. If two people who participate in the project
have 25 of 25 markers that are identical (match exactly), then their MRCA is
less than 7 generations back for them 50% of the time or 140 years on average.
Anything less than a 10 out of 12 markers or 23 out of 25 markers between two
individuals is not considered a strong match; the two people may be related, but
the common ancestor may have been quite a long time ago as you can see in the
last column of the table
The
trick is to reduce the uncertainty in the determination of that MRCA until you
have identified the individual who is the father of both of your family lines.
The ideal process starts with a verification of your own family line of DNA by
having distant male Wade cousins take either the 12 marker or 25 marker DNA
test. By proving that they both carry the exact same Y chromosome DNA, you
have a solid benchmark which you can compare with the results from other Wade
families who do the same.
As you
find Wade families with matching DNA, you must map them to your own family tree
and history. The degree to which your DNA matches determines how far back
you probably shared a common ancestor. Figure 1 below shows how this
works for 25-marker match results. The figure illustrates how you can use
the DNA data and documented family history in combination.
The
figure assumes you are test participant A, and you want to trace your ancestry
back beyond your oldest documented ancestor MRCA1. The first step is to
find a male cousin such as B in the figure to participate in the test.
(The figure shows a first cousin, but you may want to go to at least a third
cousin.) MRCA1 is the most recent common ancestor for the two of you. You
(A) and participant B should have DNA that is a perfect 25/25 marker match
because of the small number of generations between the two of you and your
common ancestor.
After
you have proven your DNA matches that of male cousin B, then you are ready to
compare your DNA with that of other test participants to find other cousins.
In Figure 1, test participant A finds that his DNA is an 24 of 25 marker match
with participant C. As illustrated in Table 1, this match means that A and
C share most recent common ancestor MRCA2 who probably lived about 350 years
ago. If test participant C has a documented ancestry back to MRCA2, then
you are in luck. If not, then you at least have another Wade with whom you
can compare research notes as you both search for MRCA2.
The last
example in the above figure is the match between A and D. In this case, A
finds that he has a 23 of 25 marker match with test participant D. As
indicated in Table 1, the 23/25 match indicates A and D are probably related,
but it also indicates their most recent common ancestor MRCA3 is farther back in
the chain of Wade males than MRCA2 -- about 570 years. Again, a fully
documented ancestry between D and MRCA3 would give you a great area in which to
focus your own research. Knowing the details of MRCA3 and his descendants
may help you find the missing links between your own MRCA1 and MRCA3.
As more
Wade males participate in the DNA testing, the number of potential matches for
your DNA increases. The more matches you find, the closer you can pin down
the MRCAs for you and the matches that you find. Creating an ancestry map
like the one in the above figure will help you know when you have identified
each MRCA.
Another
way to view these numbers and DNA is to look at the number of mutations in
markers over a period of generations. If two men are 8th generation
descendants from a common ancestor (they had a common ancestor about 140 years
ago), there are 7 births down each line to the men tested. With one
mutation out of every 500 possible chances, the following would be typical of
the test results for these two men:
-
50% of the time a 25 marker test will be identical
-
35% of the time a 25 marker test will show a one step change
-
12% of the time a 25 marker test will show two one step changes
-
3% of the time a 25 marker test will show three one step changes
Click
here
to go to the DNA 101: Y-Chromosome Testing page written by John A. Blair that
explains DNA, as it pertains to Y-Chromosome testing and genealogy, in layman
terms with as little DNA "mumbo jumbo" as possible.
Click
here to go to
the Family Tree DNA pages that explain the Most Recent Common Ancestor and the
above curve in detail. This site also gives you the MRCA curves for 12/12,
11/12, 10/12, 25/25, 24/25, and 23/25 matches.
Click
here to go to
an MSNBC page that explains the Most Recent Common Ancestor in genealogy
context. Great article!
Click
here for
the ultimate use of DNA to trace ancestors across
