Saw this on TV several weeks ago...fascinating. We only think we are smarter than man 2000 years ago because of our machines. Maybe something like this will force us to give up such silly notions.
In terms of IQ, we are identical to the first modern humans. I have no doubt we will find remarkable human achievements that were lost due to ice ages, pandemics, and other catastrophies.
I also believe that "mainstream" science down't think this way is that it is uncomfortable to contemplate a total collapse of our civilization, as others collapsed before us.