Last year I visited the Museum of Natural History in Chicago and experienced the same thing. I already had no doubts about the validity of the Evolution by then, but no facts and figures I had read stroke me so much as a Neanderthal skull I saw right next to a modern human skull and some other ape's skull. It was so clear that Neanderthals were entirely humans and, at the same time, so different from us as to constitute a different species.
I think that JW stubborn refusal to accept the Evolution will be a major obstacle for recruiting educated people outside the US, where fundamentalist christianity is not so widespread.