Sorghum was domesticated from its wild ancestor more than 5,000 years ago, according to archaeological evidence uncovered by University College London archaeologist Dorian Fuller and colleagues in Sudan.
Sorghum (Sorghum bicolor) is a native African grass that was utilized for thousands of years by prehistoric peoples, and emerged as one of the world's five most important cereal crops, along with rice, wheat, barley, and maize.
For a half century scientists have hypothesized that native African groups were domesticating sorghum outside the winter rainfall zone of the ancient Egyptian Nile Valley — where wheat and barley cereals were predominant — in the semi-arid tropics of Africa, but no archaeological evidence existed.
The newest evidence comes from an archaeological site near Kassala in eastern Sudan, dating from 3500 to 3000 BC, and is associated with the Butana Group culture.
"This new discovery in eastern Sudan reveals that during the 4th millennium BC, peoples of the Butana Group were intensively cultivating wild stands of sorghum until they began to change the plant genetically into domesticated morphotypes," Dr. Fuller and co-authors said.
The researchers examined plant impressions within broken pottery from the largest Butana Group site, KG23.
"Ceramic sherds recovered from excavations undertaken by the Southern Methodist University Butana Project during the 1980s from the KG23 site were analyzed," they explained.
"Examination of the plant impressions in the pottery revealed diagnostic chaff in which both domesticated and wild sorghum types were identified, thus providing archaeobotanical evidence for the beginnings of cultivation and emergence of domesticated characteristics within sorghum during the 4th millennium BC in eastern Sudan."
"Along with the recent discovery of domesticated pearl millet in eastern Mali around 2500 BC, this discovery pushes back the process for domesticating summer rainfall cereals another thousand years in the Sahel, with sorghum, providing new evidence for the earliest known native African cultigen," they said.
The research is published in the journal Current Anthropology.
Frank Winchell et al. Evidence for Sorghum Domestication in Fourth Millennium BC Eastern Sudan: Spikelet Morphology from Ceramic Impressions of the Butana Group. Current Anthropology, published online September 20, 2017; doi: 10.1086/693898
-- Sent from my Linux system.