9 kya. Agriculture got started in the Near East by 10,000 years ago, yesterday on Logarithmic History. But a very different agricultural system may have begun around today’s date on the margins of Kuk Swamp in the highlands of New Guinea. This early date is controversial, but agriculture was clearly in place by around 6.5 kya.
The folks at Kuk Swamp were harvesting (and at some point cultivating) root and tree products: taro, yams, and bananas. We know relatively little about the early history of such crops, and their New World counterparts like manioc and sweet potatoes, since they don’t preserve as well as grains like wheat, rice, and corn/maize.
And there may be a more consequential difference between roots and tubers, and grains. Many root crops don’t keep well once they’re harvested. Better to leave them in the ground and harvest small amounts as needed. But grains have to be harvested all at once, and then stored. And there may be a further social implication to this: in the case of grains, concentrated stores make it easier for tax collectors to step in and appropriate a part of the product. Around the world, grain agriculture eventually ends up associated with complex stratified societies, with elites supported by rents and taxes extracted from a dependent peasantry. Places where root and tree crops were the basis of subsistence were less likely to develop political organization beyond the local level. Highland New Guinea winds up illustrating this, with productive agriculture and dense populations, but tribal-scale politics.
The Andes, where the potato was first cultivated, and a succession of empires eventually flourished, may be the exception that proves the rule. At high altitudes, potatoes could be preserved by freeze drying.