SUBSISTENCE

The Sahel's Own Harvest

~4,900 years ago

History · Bronze Age · Holocene · Northgrippian

As the green Sahara died, its peoples domesticated their own cereals: pearl millet in the west, its genome tracing to the drying Saharan fringe with cultivation spreading from about 4,900 years ago, and sorghum in the eastern Sahel, its wild grains showing the marks of harvest on fourth-millennium BCE pottery. Bred for heat and drought from birth, both crops crossed to India within a millennium and 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 ignored: crops born of the Sahara's death were engineered by its survivors for exactly the climates now spreading. As the planet warms, the drought-hardy genetics of millet and sorghum have become a global resource, the old Sahel quietly insuring 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; sorghum shows domestication traits on pottery of the eastern Sahel in the fourth millennium BCE. Both grains later crossed the Indian Ocean, reaching India within a thousand years of their spread.

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