To reply to Clyde Burns concerning the situation he posed: If the two descendants had the DNA analysis, they would either match or not match, that is certain. If their Y-chromosome markers match 12 for 12, they are related, but the MRCA (most-recent-common -ancestor) may not be the grandfather or even the great grandfathers, it could go farther back. BUT MORE IMPORTANT, and a point that is being over-looked, if they do not match, then we know that those grandfathers are not brothers. We got a negative result, and in normal genealogical research, negative results (probably 75 to 85% of the time) narrow the field and allow us to concentrate elsewhere. We have all experienced this, over and over again! I agree there are "probabilities" involved with DNA, but in this example of a negative result, it looks to me like a bullseye! Don, please comment if I have strayed from the mark. (co-administrator, Max).