Since last I mentioned Jim McKown, brother Dick suggested that the probable reason
that Jim's family tree doesn't match his DNA is that there is an error in the family
tree because DNA doesn't lie. Jim confirms that from about 1785 to present, his family tree reflects his own research and the part going back to 1685 in Perth, Scotland, was furnished by another researcher. That doesn't mean that the research was bad by either researcher but that the tree is grafted where it shouldn't oughta be.
FTDNA has a tool to predict the percent probability that two men who match had a Most Recent Common Ancestor (MRCA) so many years ago, with the usual comparison by four generations apart. Cousin Sam, descended from the younger brother of my great grand father, and Jim McKown and I have MRCA's that differ by only hundredths of a percent at any generation going back 24 generations (600 years ago at 25 years per
The case is further strengthened in that only Sam and Jim match me exactly at 12 and 25 markers and at 36/37. Sam has his 67 marker result and it is a 66/67 match.
The next best matches from other men to date are 24/25, 34/37 and 63/67 and I consider those as very important as well.
As far as I am concerned, Jim, Sam and I are related based on our surname and 36/37 matches alone. The MRCA is icing on the cake and I fully expect when Jim's 67 marker results come in, that he will match me at 66/67 as well. Oh, by the way,
by calculating the MRCA by each generation, Sam and I have enough percentage of probability to be judged by two FTDNA Group administrators as close enough to show
a relationship 7 generations ago, which comes out as 175 years ago. Since it is only 140 years from my great great grandfather's birth to mine that MRCA could have been in only as far back as 1755.