Herbaria reveal cost of the Green Revolution

Description Rapid weed evolution is exposed by genome sequencing of natural history collections A visitor to the US Midwest will be immediately struck by the sheer scale of industrially farmed corn and soybean. These fields are intensively managed artificial ecosystems, from their planting and harvesting timelines to the fertilizers and pesticides that are continually applied. Evolutionary biologists have long presumed that weeds are under strong natural selection to adapt to this anthropogenic ecosystem, which first appeared in the mid–20th century’s “Green Revolution” in agriculture. On page 1079 of this issue, Kreiner et al. (1) report that the selection pressure on weeds in modern agricultural fields is higher than estimates from most other natural systems (2). The authors leverage historical samples in natural history collections to temporally link the adaptation of the agricultural weed waterhemp to the Green Revolution.