We will select volunteers from those two branches,

If you didn't have that genealogical information, you wouldn't have the first idea about those two branches or where they come from.

But generally this is the kind of name that, from experience, has one or very few founders.

If it's a single family with one original founder, then most of them will have the same Y chromosome fingerprint. If there's more than one, we'll identify that,

There are several interesting questions such as was there one original 'father' Christmas or were there several different ones?

By looking at the details of the DNA, it is possible to chart the flow of your ancestry from your ultimate grandmother to more modern times.