I am just getting a single-surname DNA project going and have one taker who's asked a good question: Is there any utility in brothers having the same father getting tested? I'm new at this myself and would appreciate advice from those with more expertise (which should be just about everybody). Cheers, Everyone.
Judith - absent other unusual circumstances, I wouldn't recommend testing living brothers, especially if you are extremely confident that they have the same father. There wouldn't be much to gain from that expense. Their Y-DNA will be almost completely identical.
However, if you are referring to brothers a few generations back, there might be some benefit. For example, I am trying to recruit to my surname project the descendants of brothers who were born in the late 1700's/early 1800's, just to confirm my own results as being from the original immigrant father of those brothers.
This is a simplistic answer, so please feel free to ask more questions if your specific question wasn't addressed!
Super! Thanks for the prompt replies -- it's what I was thinking. I'm am going to suggest that instead they pool their money on a 67-marker test for their father, who is still living.
Blaine--Why test the most distant relative? Do you mean eldest? Sorry for not understanding this but wouldn't I get useless info from say my mother's second cousin? Jennifer
I did mean eldest, and I even tried to think of a better word than "most distant" when I was typing it! Thank you for helping me out on that one!
I usually recommend the ELDEST ancestor because I like to get their DNA on file and because they are usually one or a few generations closer to the ancestor in question (thus fewer chances of mutation, etc...), among other reasons.