Bob Carlyon

r wine was imported to the port of Lattara in southern France as early as 400 BC (Proc. Natl. Acad. Sci USA (2013) 110, 10147–10152). The discovery of a wine press at the same site shows that the resident Celts moved on swiftly from importing Etruscan wine to importing the technology and making their own. More recent instances of agriculture shaping society include slavery in the Americas, where sugar cane was seen as an ideal crop to be harvested by slaves, while other crops, such as tobacco, grown in the same area, required the care of free farmers, much like the cereals of cooler regions. Settlers adjusted their values accordingly, and even Puritans fleeing England in search of freedom became slave holders, as Bowles has outlined in an essay (New Scientist (2011), July 30, 26–27). To this day, we find that the sum of the many small actions undertaken to give us our daily bread often add up to unintended consequences that impact our lives in ways neither foreseen nor desired. The introduction of synthetic fertilisers averted global famine but burdened our planet with a doubling of its nitrogen turnover (Curr. Biol. (2012) 22, R1–R4). The arrival of European farming methods in Australia has endangered the health of the coral reefs off its coasts. And the tendency of people to settle close to where their food is produced has led to the paradox that much of the world’s most fertile agricultural land is now covered by urbanisation. Erle Ellis from the University of Maryland at Baltimore, US, and colleagues have recently argued that the impact of land-use on the biosphere hasn’t started with the recent advent of tractors and fertilisers, but that it has been a continuous development since the beginning of the Holocene (Proc. Natl. Acad. Sci. USA (2013), http:// dx.doi.org/10.1073/pnas.1217241110). All of which seems to suggest that it is time we humans invested more thought in how we produce our food and made sure we can control the impact of the species we allegedly domesticated. Otherwise, an observer from outer space might come to the conclusion that the crops domesticated us.