Did the Neandertals jump, or were they pushed?

John Hawks is involved in a bit of a stir by suggesting that there was little or no overlap between sapiens and neanderthalensis occupation in the Near East and Europe. A Yahoo report today gives the claims of those for and against the idea of there being little overlap. It seems that Aurignacian culture, which ended around 29,000ybp, may have been Neandertal, rather than modern human. This may also put a dent in the view some have that Neandertals and modern humans interbred, although I gather that is not a popular hypothesis anyway. Fun to watch from the sidelines...