I agree. Apparantly that was a cataclysmic event that would have killed off- what?- most of "humanity" at that point. The ones that survived an event of that magnitude would have been a)just plain lucky and b)"the sharpest knives in the drawer".
It would be the genetic jump they're looking for simply by loading the gene pool from the deep end- so to speak. It would favor those groups and individuals who were not only brighter but able to apply their wit toward their immediate well being (and possibly also put darwinistic pressure on planning for the future).
The first condition I understand, but what special skill would enable one to survive an unplanned catastrophe? Unless it was something like the dumb ones heard the rumblings and went to investigate and the smart ones left for high ground.
Food and shelter would not have been a problem. Think of all of the coconuts on the ground and the gratis lean-tos available for the occupancy. Well, maybe with all the spare time given the free food and shelter, the proto-humans would have had mucho time on their hands. In order to keep the inevitable fights due to boredom in check, the hootenanny would have been invented. With all the hooten-and-hollerin going on more food on the hoof would have been attracted and the cycle would build on itself. Thus small change by small change the proto-human would turn into the civilized beast he is today.