There is an interesting wiki page on the history of writing.
I'd never given it too much thought before, beyond having the vague idea that it had started in what we now call the middle east, in a rich agricultural area based on virgin riverside topsoils.
Written number systems originated in the same area (now part of Iraq) -
The earliest known writing for record keeping evolved from a system of counting using small clay tokens that began in Sumer about 8000 BC.http://en.wikipedia.org/wiki/SumerThe cities of Sumer were the first civilization to practice intensive, year-round agriculture, by perhaps c. 5000 BC showing the use of core agricultural techniques, including large-scale intensive cultivation of land, mono-cropping, organized irrigation, and the use of a specialized labour force. The surplus of storable food created by this economy allowed the population to settle in one place, instead of migrating after crops and grazing land. It also allowed for a much greater population density, and in turn required an extensive labour force and division of labour. Sumer was also the site of early development of writing, progressing from a stage of proto-writing in the mid 4th millennium BC to writing proper in the third millennium (see Jemdet Nasr period).
The earliest known writer of literature was a woman, an Akkadian princess from Sumer, called Enheduanna.
http://en.wikipedia.org/wiki/Enheduanna (an example of her work - http://etcsl.orinst.ox.ac.uk/cgi-bin...72.p7#t4072.p7 ) The concept of writing spread, and new forms of writing were developed. There were also, later, separate developments of writing - in America first and also in China and quite a few other places.
Writing is important -
Writing has made possible the spread knowledge and culture through large populations and also allowed for an increasingly rapid development of new knowledge, standing on the shoulders of what was known before.The great benefit of writing systems is their ability to maintain a persistent record of information expressed in a language, which can be retrieved independently of the initial act of formulation.
The benefits of writing were constrained when each copy had to be hand written. Many important works have been lost from that period.
The development of the printing press in the 15th century "cracked open" the potential of writing for societal development. Written works were far more accessible and less likely to be lost.
The internet (developed in the 1950s-80s), likewise, has had an exponential effect on the sharing and spread of knowledge, in that it has provided a much cheaper and more readily available global means of access to writing.
Thousands of free books and articles (damn you, pay walls!)
Both of these developments have come about on the back of the general level of technological and scientific development in society.
One would think that writing might be challenged by development of recorded sound - I have just listened to a talk by Conor McCabe, on youtube, for example, that once would have been more likely shared by means of a pamphlet, or that would not have been heard beyond the initial live audience.
But writing is in many ways superior - a moment's lapse of concentration when listening to a recording means the tedium of playback and listening again, maybe more than once. Reading a written version, one can go at one's own pace.
Perhaps the next step will be some form of direct plug-in of information into the brain.