Age· The columns of time
Neolithic
11.7 ka → 3,275 BCE
People stop following their food and start growing it. Within six millennia the species becomes sedentary, far more numerous, and dependent on a handful of plants it has reshaped. Almost everyone alive still lives under that arrangement.
What the evidence shows
Cultivation and domestication of wild plants begin across the Fertile Crescent from about the eleventh millennium before present, and the study of the Jordan Valley shows what made them possible in one place at least. The soils there were built from Saharan dust blown north during the arid phases of the ice age, and fresh groundwater returned to the neighbouring mountains between 12,000 and 11,000 years ago, across the end of the Younger Dryas and after it. The valley's first farming villages, late Natufian and Pre-Pottery Neolithic, stand where the fertile soil and the water met. Farming was not thought up in the abstract; it was made possible somewhere.
Bounds and conventions
There is no single Neolithic, and treating it as one event is the commonest mistake made about it. Farming was invented independently in at least a dozen regions, at dates spread over five millennia, and reached others by diffusion much later. Radiocarbon on tooth enamel now places the aceramic Neolithic of Mehrgarh, in Pakistan, between 5200 and 4900 BCE rather than around 8000 BCE, three millennia later than long supposed.
Regional: the Neolithic begins around 11.7 ka in south-west Asia, millennia later elsewhere, and never at all in some regions.