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From: Bob McLaren <>
Subject: Re: [DNA] DNA questions for a beginner
Date: Sat, 6 Nov 2010 09:57:37 -0400 (GMT-04:00)


Vern,

I'm not sure if you got an answer, so I will jump in. Your questions:

1a. Yes, if you and your second cousin are straight line male descendants of the two brothers, a DNA test on you and your second cousin will show if the same man was the father of the two brothers.

1b. It doesn't really matter which generation tests, even if they are of two different generations. In cases where I have the opportunity to select the generation, I prefer to choose the oldest. This is to reduce the very small probability that a mutation happened between father and son. So, in your case, I would test you and the son of your second cousin if your second cousin did not want to test. If he does, however, I would test your second cousin over his son.

1c. You want to do a Y-DNA test. The Y-chromosome is passed from father to son, to his son, to his son, etc. without any changes (except for those due to a very slow mutation rate). I recommend the 67-marker test at Family Tree DNA as the most comprehensive.

2. If a surname appears as a middle name, and if it reflects parentage, then it is most likely a maternal surname. Your Y-DNA tests reflect your paternal heritage, not maternal. While you could check Y-DNA results for that surname, they would not match your results. At this time, you need to use convention genealogy to determine if that surname is on one of your maternal lines.

Yours aye,

Bob McLaren
Genealogist, Clan MacLaren Society (based in Scotland)
Chairman, Genealogy Committee, Clan MacLaren Society of North America
Administrator, Clan MacLaren Surname DNA Project (Worldwide)
Administrator, Lindo, da Silva, and Braham Surname DNA Projects (all Worldwide)
Member, Association of Professional Genealogists
Member, Genealogical Speakers Guild


-----Original Message-----
>From: Vern Prescott <>
>Sent: Nov 1, 2010 11:57 PM
>To:
>Subject: [DNA] DNA questions for a beginner
>
>Hello List members
>
>I have joined the list to seek guidance from people with experience with DNA
>testing. I hope I am able to put my questions in a way that people will
>understand.
>
>Let me briefly describe my situation. My great grandmother was never
>married but had 6 children. She had two sons, one being my grandfather. I
>have just managed to determine who my grandfather's brother was, and am in
>touch with some of his descendants. Now for my questions?
>
>1. I would like to try DNA on myself and on a second cousin, if I get
>agreement, thinking that I would be able to determine if my grandfather and
>his brother had the same father or different fathers.
> a) Am I correct in thinking that DNA would do this for me? ( both I
>and the other person would be male line descendants)
> b) If I can not get agreement form a second cousin, would it be
>advisable to use my son and his third cousin rather than myself and a second
>cousin, once removed? I would think that keeping the same generation would
>make for an easier comparison.
> c) what type of DNA testing would be required to do this?
>
>2. My grandfather also had sisters, one of whom had a "surname" as a middle
>name, possibly suggesting parentage. If I discover that my grandfather and
>his brother had the same father, am I correct in thinking that I could then
>check against data from people of the "other" surname to see if there was a
>match, and possibly find my great grandfather (or his brother) by doing so?
>Given a start, I could use other, more conventional techniques, to try to
>determine the correct lineage.
>
>
>My reasoning is that if two sons had the same father, possibly all the
>children had the same father. I assume this is a long shot, but better than
>any other methods available.
>
>Vern in Ontario


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