John & Richard,
Perhaps I can give some examples of why you might match 25 for 25 with someone with a different surname, using my own Blair study. As in the case of many Scottish surnames, the Blair surname has "mixed" with other surnames.
The Blair surname goes back to approximately 1165 when King William I of Scotland conferred to a Norman, Jean Francois, the title Barony of Blair. Jean Francois' son adopted the surname "de Blare" and became the Blair of Blair. The title Blair of Blair continued through a direct line of male Blair descendants until about 1700 when the only surviving child of the Blair of Blair was a daughter Magdelene. Magdeline married William Scott, who adopted the Blair name and coat of arms and became the Blair of Blair. Any descendants of William Scott Blair would carry the DNA of Scott though they carry the name Blair.
In 1600 Alexander Blair, a direct descendant of John Blair (the Blair of Blair) and Grisel Sempill, but NOT heir to the title, married Elizabeth Cochrane, the only daughter and heiress of William Cochrane of Cochrane. Alexander adopted the name and arms of Cochrane in lieu of Blair and became the ancestor of the Earls of Dundondonald. Any descendants of Alexander Blair Cochrane would carry the DNA of Blair though they carry the name Cochrane. Their DNA would also link them to the original Blair of Blair.
These are just two case of name adoption in Blair surname. I'm sure further research would reveal others.
Obviously, as Project Coordinator for the Blair DNA Project, I am most interested in any DNA studies performed by Cochrane or Scott, as matches to these names could provide valuable insight into Blair genealogy.
There is also the case of adoptions. I am a 25 for 25 match with a participant with the surname Philbrick. In our case we know that Philbick's great grandfather was born a Blair but adopted by Philbrick. We also know with almost certainty who our common ancestor is. If Philbrick did not know is great grandfather was adopted we might not have made the connection.
Another participant in our project does not have a Blair surname (I'll call him Smith). His gr-gr-gr grandfather was born out of wedlock and was given his mother's maiden name even though his father was a Blair. Smith's DNA will be Blair. If he searched for matches with other Smith's he might never find any.
In both of these two "non-paternal" events the participants knew of there existence. But how many other participants in DNA projects have similar "non-paternal" events that they are NOT aware of?
John, you say you have "very extensive and well documented records over the last 12 generations" and that you "Have no doubt about the paternity of any of those in my documented records." I'd say you are much luckier than 99% of the rest us tracing our ancestors, considering how sketchy most of the older records are. But even if you are correct about the last 12 generations, what about generation 13 or 14 or 15. Are you certain that no "name change" or "non-paternal" event did not occur?
Considering the Blair name goes back about 30 generations and all that has happened with just one line of the name how can you be certain that similar changes did not occur with your surname?
John
Perhaps I can give some examples of why you might match 25 for 25 with someone with a different surname, using my own Blair study. As in the case of many Scottish surnames, the Blair surname has "mixed" with other surnames.
The Blair surname goes back to approximately 1165 when King William I of Scotland conferred to a Norman, Jean Francois, the title Barony of Blair. Jean Francois' son adopted the surname "de Blare" and became the Blair of Blair. The title Blair of Blair continued through a direct line of male Blair descendants until about 1700 when the only surviving child of the Blair of Blair was a daughter Magdelene. Magdeline married William Scott, who adopted the Blair name and coat of arms and became the Blair of Blair. Any descendants of William Scott Blair would carry the DNA of Scott though they carry the name Blair.
In 1600 Alexander Blair, a direct descendant of John Blair (the Blair of Blair) and Grisel Sempill, but NOT heir to the title, married Elizabeth Cochrane, the only daughter and heiress of William Cochrane of Cochrane. Alexander adopted the name and arms of Cochrane in lieu of Blair and became the ancestor of the Earls of Dundondonald. Any descendants of Alexander Blair Cochrane would carry the DNA of Blair though they carry the name Cochrane. Their DNA would also link them to the original Blair of Blair.
These are just two case of name adoption in Blair surname. I'm sure further research would reveal others.
Obviously, as Project Coordinator for the Blair DNA Project, I am most interested in any DNA studies performed by Cochrane or Scott, as matches to these names could provide valuable insight into Blair genealogy.
There is also the case of adoptions. I am a 25 for 25 match with a participant with the surname Philbrick. In our case we know that Philbick's great grandfather was born a Blair but adopted by Philbrick. We also know with almost certainty who our common ancestor is. If Philbrick did not know is great grandfather was adopted we might not have made the connection.
Another participant in our project does not have a Blair surname (I'll call him Smith). His gr-gr-gr grandfather was born out of wedlock and was given his mother's maiden name even though his father was a Blair. Smith's DNA will be Blair. If he searched for matches with other Smith's he might never find any.
In both of these two "non-paternal" events the participants knew of there existence. But how many other participants in DNA projects have similar "non-paternal" events that they are NOT aware of?
John, you say you have "very extensive and well documented records over the last 12 generations" and that you "Have no doubt about the paternity of any of those in my documented records." I'd say you are much luckier than 99% of the rest us tracing our ancestors, considering how sketchy most of the older records are. But even if you are correct about the last 12 generations, what about generation 13 or 14 or 15. Are you certain that no "name change" or "non-paternal" event did not occur?
Considering the Blair name goes back about 30 generations and all that has happened with just one line of the name how can you be certain that similar changes did not occur with your surname?
John
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