I’ve been meaning to read this for a while — even before coming across it in Steven Pinker’s The Language Instinct — because genes and languages are two interests of mine. I’m not much for statistics and I found it difficult to follow some of the analyses of the data in this book, but fortunately, Cavalli-Sforza and his translator managed to put the conclusions across quite clearly. I’m surprised to see opposition to the idea that the spread of genes and languages can be mapped onto each other fairly closely, with some exceptions; Darwin predicted it, and according to the data here, it’s fairly clear.
I think the book might’ve benefited from a tighter focus, all the same; it seemed like the language chapter/s went off on a tangent somewhat. Still very interesting, and no doubt out of date by now — my edition says 2001 — so I really should look for more up to date stuff.