Yes they did!
Excellent story too, by the way.
Jared Diamond wrote an excellent summary about the entire story.
He's a bit of a left-wing apologist for the success of white people, but his science is normally spot-on if you throw out the PC bits.
If you like that, Jared Diamond wrote two excellent books that I can highly recommend - even though he is a semi-rabid left-winger...
Guns, Germs and Steel
I forgot the other one, but if you like the one I posted above, FReepmail me and I'll look it up again.
:)
Guns, Germs, and Steel was a really cool book. A real thought provoker.