Cereal Domestication May Have Started 10,000 Years Earlier than Scientists Thought

According to a new study published in the Philosophical Transactions of the Royal Society B, ancient peoples began to systemically affect the evolution of crops up to 30,000 years ago — around 10,000 years before researchers previously thought.

Barley (Hordeum vulgare). Image credit: Cliff.

Wild plants contain a gene which enables them to spread or shatter their seeds widely.

When a plant begins to be gathered on a large scale, human activity alters its evolution, changing this gene and causing the plant to retain its seeds instead of spreading them — thus adapting it to the human environment, and eventually agriculture.

University of Warwick Professor Robin Allaby and his colleagues from University College London and the Universities of Tsukuba and Warwick made calculations from archaeobotanical remains of einkorn, emmer wheat, rice, and barley that contained ‘non-shattering’ genes.

“Our shows that crop plants adapted to domestication exponentially around 8,000 years ago, with the emergence of sickle farming technology, but also that selection changed over time,” the researchers said.

“It pinpoints the origins of the selective pressures leading to crop domestication much earlier, and in geological eras considered inhospitable to farming.”

In Tell Qaramel, an area of modern day northern Syria, the study demonstrates evidence of einkorn wheat (Triticum monococcum) being affected up to 30,000 years ago.

Furthermore, emmer wheat (Triticum dicoccon) is proved to have been affected 25,000 years ago in the Southern Levant, barley (Hordeum vulgare) in the same geographical region over 21,000 years ago, and rice (Oryza sativa) in South, East and South-East Asia more than 13,000 years ago.

“Demonstrating that crops were being gathered to the extent of being pushed towards domestication up to 30,000 years ago proves the existence of dense populations of people at this time,” the scientists said.

“This study changes the nature of the debate about the origins of agriculture, showing that very long term natural processes seem to lead to domestication — putting us on a par with the natural world, where we have species like ants that have domesticated fungi, for instance,” Professor Allaby said.

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Robin G. Allaby et al. 2017. Geographic mosaics and changing rates of cereal domestication. Phil. Trans. R. Soc. B 372 (1735); doi: 10.1098/rstb.2016.0429