This volume is published at a critical juncture in the history of human impact on the biosphere – a history we can trace back some 10 000 years – to the era of the agricultural revolution. Now, in retrospect, we see a revolution that was indeed slow and by today’s definition, hardly a revolution. Nevertheless, it was fast enough to feed a growing population and see it through several food crises. But it also was a time during which the rate of species extinction rose dramatically and changed the natural environment. This loss of the genetic wealth of our biosphere was slightly compensated by the agricultural biodiversity that humans ingeniously developed in their fields which ultimately spread and evolved into components of our diverse agricultural ecosystems.