How the extinction of Ice Age mammals may have forced humans to invent civilization
(PHYSorg.com Archaeology & Fossils)

Why did we take so long to invent civilization? Modern Homo sapiens first evolved roughly 250,000 to 350,000 years ago. But initial steps towards civilization-harvesting, then domestication of crop plants-began only around 10,000 years ago, with the first civilizations appearing 6,400 years ago.