Why did modern human populations disperse from Africa ca. 60,000 years ago? A new model
The thing is, this is nearly indistinguishable from Richard Klein's model. There are only two possible distinctions between Mellars and Klein. The first is with regard to the Skhul and Qafzeh hominids: Klein interprets these as "near-modern" samples lacking significant evidence of modern behavior; Mellars accepts evidence for symbolic behavior at Qafzeh including possible grave goods, perforated shells, and pigment use.
The second is that Mellars interprets Klein as supporting a "sudden change in the cognitive capacities of the population involved, entailing some form of neurological mutation" (Mellars 2006:9384) at 40,000 to 50,000 years ago. In contrast, Mellars supports either a sudden change or a gradual change in cognitive capacities, entailing either neurological mutations or environmental changes, at 80,000 years ago.
So I guess the only difference is the timing, since I read Klein as essentially agnostic about the mechanism of cognitive evolution (he mentions mutation as a possible mechanism, but clearly has no specifics on this point).
And if Mellars is willing to accept that the Qafzeh burials are evidence of symbolic behavior, it is hard for me to see how his position can be differentiated from d'Errico, who after all has only pointed out that similar evidence for Neandertal symbolic behavior must be interpreted in similar cognitive terms. Now that seems to me like an impossible coincidence...