The evolution of writing

Just over 5,000 years ago, the earliest cities flourished in Mesopotamia and western Iran. One explanation that has been considered is that making these areas with their seasonal alternations of flooding and drought amenable to agriculture required a complex infrastructure for water retention and irrigation. Thus, only a critical mass of workforce and a certain level of organisation could make these lands habitable, leading to urban settlements like Uruk in Mesopotamia and, a few hundred kilometres to the east, Susa in Iran. On the other hand, humans adapt well to diverse climatic conditions, and southern Mesopotamia may have lent itself to the growth of incipient complex societies without the need for large-scale hydraulic management as more current archaeological theories suggest. Whatever their origin, the complex societies that built these early cities soon found they needed to keep records of their stocks, property, and commerce. The people of Uruk came up with proto-cuneiform, which evolved into cuneiform. This script encoding words and syllables was eventually supplanted in the Middle East by Michael Gross reports.