Human existence on planet earth dates back to some 200.000 years. However, I consider the invention of ideographic writing by the ancient Sumer, as the starting point of human civilisation, which is around 3200 BCE.
Without a tool that can convey life-time learning experiences of individuals of any species to their offspring, it would not be incorrect to assume that all newborns would start their lives from where their parents did and very little knowledge would accumulate throughout centuries, if not millenniums. Humankind would certainly maintain its biological existence for millions of years until some big disaster hits, but probably there would not be a significant difference between the daily life 200.000 years ago and what we are doing today. There would be eras of rediscoveries and probably many great inventors, reinventing the same simple machines. If the question of whether or not Socrates had ever lived still lingers today, whereas Plato's ideas are being discussed rather than his life, it is due to the fact that Plato did the writing while Socrates was doing the talking.
It is true that all mammals are evolving, but the type of mammal that could publish this website is different from all other species only in one aspect, which is not skills of using some iGadget: this mammal can write. Written communication started an accelerated evolution process and if the universe will ever be decoded one day, its codes will need to be written somewhere, somehow. Please click on the scripture image above, to visit the website it was borrowed from.
Writing is more than a "game changing technology", I would rather call it the beginning of the game, a sort of first move in chess that opens the game, without which there would be no game to talk about.
...whereas all human beings of even quite low I.Q. become competent native speakers, not everyone is able to acquire similar competence in the derivative, written, medium. Spoken language does not have to be taught; written language, by and large, does.
"Writing and Reading" UNIVERSITY of PENNSYLVANIA. Department of Linguistics, n.p, n.d. retreived on Web. 01 Feb. 2013.