http://www.historian.net/hxwrite.htm
Language existed long before writing, emerging probably simultaneously with sapience, abstract thought and the Genus Homo. In my opinion, the signature event that separated the emergence of palaeohumans from their anthropoid progenitors was not tool-making but a rudimentary oral communication that replaced the hoots and gestures still used by lower primates.
The transfer of more complex information, ideas and concepts from one individual to another, or to a group, was the single most advantageous evolutionary adaptation for species preservation.
As long ago as 25,000-30,000 years BP, humans were painting pictures on cave walls.
Written language was the product of an agrarian society.
For the next step toward the development of an alphabet, we must go to Egypt where picture writing had developed sometime near the end of the 4th millennium BC.
