Comment by brockers
It might be just my perception, but it seems like every single time anthropologist make statements to the effect that complex human development didn't start until XX they are proven wrong. It wouldn't bother me so much if it wasn't for the fact that those "estimates" are generally used as proof to dismiss alternative timelines for human progression. I'm certainly not trying to say the planet had Atlantis with flying cars 300,000 years ago; but it certainly seems plausible that there were large/complex societies beginning long before the advent of our current written history... an idea that is regularly dismissed as foolish.