FamilyTree DNA MRCA (Most Recent Common Ancestor) Chart
The FamilyTree DNA MRCA (Most Recent Common Ancestor) Chart works well for reasonably close relationships.
It does not work very well for distant relationships such as the relationship of Group 1 and Group 2 McCains.
Therefore I modified the chart to add more mis-matchs per Marker in some cases. The mis-matches that I
added are highlighted in RED. I came up with my added generation data by
comparing generation data vertically and horizontally and tried to keep the same rate of generation progressions
going in my added mismatches. While my added data may not be totally accurate the data is "close enough for
government work" as the saying goes. After all, data in the chart, even the FTNA data, is a "scientific
estimate", not a hard fact. Note: Blue Line separates different Marker Tests, i.e., 10 Marker, 12 Marker, 25 Marker,
37 Marker, and 67 Marker Tests.
You will note that all FTDNA given data (yellow background) is 10 generations or less for a 50% Probability. There is
one exception, 23 of 25 Markers is 11 generations. I think that there is a reason for this. I can't find it in writing
on the FTDNA Web Site but I think that FTDNA considers testees to be related only if there are 10 generations or less
to their MRCA. I guess that you would call 11 or more generations to be distantly related. So any time we do a compare
that falls in one of my aded red background matches you might say that we are "barking up a tall tree", i.e., the success of
finding the MRCA will be extremely difficult at best.
| Markers |
50% Probability |
90% Probability |
95% Probability |
|
|
|
|
| 10 of 10 Matches |
16.5 Generations |
56 Generations |
72 Generations |
|
|
|
|
| 9 of 12 Matches** |
39 Generations |
58 Generations |
86 Generations |
| 10 of 12 Matches** |
28 Generations |
46 Generations |
66 Generations |
| 11 of 12 Matches |
17 Generations |
39 Generations |
47 Generations |
| 12 of 12 Matches |
7 Generations |
23 Generations |
29 Generations |
|
|
|
|
| 23 of 25 Matches |
11 Generations |
23 Generations |
27 Generations |
| 24 of 25 Matches |
7 Generations |
16 Generations |
20 Generations |
| 25 of 25 Matches |
3 Generations |
10 Generations |
13 Generations |
|
|
|
|
| 32 of 37** Matches |
18 Generations |
30 Generations |
34 Generations |
| 33 of 37** Matches |
13 Generations |
23 Generations |
26 Generations |
| 34 of 37** Matches |
9 Generations |
17 Generations |
19 Generations |
| 35 of 37 Matches |
6 Generations |
12 Generations |
14 Generations |
| 36 of 37 Matches |
4 Generations |
8 Generations |
10 Generations |
| 37 of 37 Matches |
2.5 Generations |
5 Generations |
7 Generations |
|
|
|
|
| 62 of 67** Matches |
14 Generations |
24 Generations |
38 Generations |
| 63 of 67** Matches |
11 Generations |
21 Generations |
29 Generations |
| 64 of 67** Matches |
8 Generations |
17 Generations |
21 Generations |
| 65 of 67 Matches |
6 Generations |
12 Generations |
14 Generations |
| 66 of 67 Matches |
4 Generations |
8 Generations |
9 Generations |
| 67 of 67 Matches |
2 Generations |
4 Generations |
6 Generations |
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