Converting

[R00tKiT]

That isn't how evolution works. You get tiny, incremental changes over thousands of generations.

I think you're underestimating the effect tiny changes can cause, especially when they involve the brain. It's well known that the smallest brain incison might cause huge impairement in speech, memory, etc. It's not excluded then that our brains "became modern" as a result of a seemingly insignificant change in our neurological system. I mean, we had to become modern at some instant.