DNA suggests a pair of brothers

[Baird2]

Well, after seeing known DNA results in my Ferguson family tree show multiple matches to people in another Ferguson line, questions arose as to how and why. Both families are from Bangor, Ireland (Northern Ireland today) and have a mariner history. Addresses were in same locations and one even matched. The earliest possible connection would be Capt. Thomas Ferguson (1816), whose Father was Capt. Matthew Ferguson. Is this James Ferguson, in the other line, a brother?

I did a lot of research on the other Ferguson line so that I could use DNA Painter's what are the odds tool. Results were 96-97% that they are brothers.

I feel like it is worth trying to prove with research, but was told it was ok to add their line to my tree  if I placed a record saying how and why I came to that conclusion.

Being new in the DNA field, I would appreciate other thoughts.

[Biggles50]

DNA is regarded as reliable for six generations, the lower the shared cM, the lower the likelyhood of it being an actual DNA match and a “false positive” instead.

That said I have DNA matches which have valid lines back into the 1700’s and if WATO gives the probability of the relationship at a level that is acceptable plus you have the BMD and other records for each person in the line then yes, do include them in your tree.

Adding a file to your tree explaining the methodology and reference said file in each person in the line and you will have as good a record as you can get.  Do include the DNA cM values for each person that you have incorporated in your tree with whom you share DNA.

A job well done.

[Baird2]

Many thanks for the feedback. I appreciate the information as I want my tree accurate versus big and hoping it is correct. With luck, I will take this family back farther. Well done getting your tree back so far!

The DNA is confusing, so your pointers on it are very helpful.

Thank-you.