No, there has to be selective pressure if we're not just talking about random drift. For hominids, sophisticated brains have been an incredibly rewarding evolutionary strategy despite the staggeringly expensive energetic costs they incur. Foraging is an intellectually demanding activity as we do it, so anything evolution can do from minimizing other expensive tissues (expensive tissue hypothesis) to high calorie oriented food selection to prosociality feeds back into improving fitness.
The timeline is pretty suspect there though. 35kya is far, far too late for any sort of behavioral modernity as that term is typically used.
The timeline is pretty suspect there though. 35kya is far, far too late for any sort of behavioral modernity as that term is typically used.