SUBSISTENCE

The Sahel's Own Harvest

~4,900 years ago

History · Bronze Age · Holocene · Northgrippian

As the green Sahara died, its peoples domesticated cereals of their own: pearl millet in the west, its genome pointing to the western Sahara, its cultivation expanding from about 4,900 years ago; and sorghum in the eastern Sahel, its seeds leaving impressions in fourth-millennium BCE pottery that already show marks of domestication. Born in heat and drought, the two crops crossed the Indian Ocean into India, pearl millet in under a thousand years, and they feed hundreds of millions today.

Why it matters

Africa is a cradle of agriculture in its own right, a fact the wheat-and-rice version of history long overlooked: these are crops born of the green Sahara's end and shaped by its survivors, in the very conditions now spreading. As the planet warms, the drought-hardy stock of millet and sorghum has become a global resource, the old Sahel quietly underwriting the future of farming far beyond it.

Dating & uncertainty

Pearl millet genomes locate its domestication in the western Sahara, with cultivation expanding from about 4,900 years ago, as the desert dried; seed impressions on eastern Sahelian pottery of the fourth millennium BCE show sorghum already carrying some domestication traits. Both grains later crossed the Indian Ocean into India; for pearl millet, present data put that passage at less than a thousand years.

Sources

1. Burgarella et al. (2018), Nature Ecology & Evolution · A western Sahara centre of domestication inferred from pearl millet genomesdoi:10.1038/s41559-018-0643-y
2. Winchell et al. (2018), African Archaeological Review · On the origins and dissemination of domesticated sorghum and pearl millet across Africa and into Indiadoi:10.1007/s10437-018-9314-2
3. Larson et al. (2014), PNAS · Current perspectives and the future of domestication studiesdoi:10.1073/pnas.1323964111

Our species’ history as one day

23:37:3622 min 24 s before midnight

if the 315,000 years of Homo sapiens were compressed into a single day