That's a good book, but it exagerates the claims. I got in contact with the guy (that actually has those last names) and he explained me several things. I don't agree, though, in his extreme diffusionist ideas, and less that maize was known in Africa in precolombian times!
However, the evidence he shows on musical instruments, mining and other topics are quite interesting.
I wonder if a serious profesional scholar would ever took this topic and try to filter the true from the fantasy.