For a hundred years, the standard timeline of cereal domestication has run something like this: people start cultivating wild grasses, plowing disturbs the soil, deeper burial favors bigger seeds, bigger seeds get resown, and grain size creeps upward generation by generation until you have something recognizably domestic. Then, later, the seeds stop shattering off the stalk. Grain size first, non-shattering rachis second. That sequence has been treated as one of the more solid load-bearing facts in the whole domestication story.
A new study in PNAS,1 led by Jade Whitlam of Oxford with colleagues from Oxford and Kiel, tests the middle part of that chain and finds it doesn’t hold. The bigger grains were there. The genetic selection wasn’t, not yet.
