Children's DNA

[Cockney_si]

Nothing related to anything I've put on here before, just curious....

If a woman has a child by a man and then has another child by the man's brother, both children turn out to be boys....

Is the DNA of the two boys likely to look similar when studied as they have similar "family" traits ?

[China Doll]

Might be an idea to put this in science.

I read a book recently in which a sperm sample had been sent to a lab and I believe they had a sample of some sort of bodily fluid from a grand father of a family so the lab was able to deduce that the sperm sample came from one of the lads in that particular family. At this point I should say taht the book in question I was reading was a scandinavian murder mystery so I have no idea if my answer is anything even remotely resembling a fact! :c)

[Brinjal]

Similar but not the same unless the brothers are twins.

[atalanta]

There was a similar plot in the radio 4 soap opera "The archers" - some years ago. Each of 2 brothers claimed to be the father of a boy, but DNA analysis did distinguish which of the 2 brothers was the real father of the child.
Each parent contributes 50 percent of a child's DNA, but never the same 50 percent to any 2 children.

[karenmac60]

Presumably it would be about as similar as full brothers' DNA...