Introduction: Agricultural biodiversity, the key to sustainable food systems in the 21st century

Agricultural biodiversity - the plants, animals and microorganisms that contribute to food and agriculture and whose diversity is the result of interactions between people and their environment over many millennia - represents one of humanity’s greatest resources. Despite supplying large volumes of some agricultural commodities to markets, agriculture and food systems still fail to feed a significant part of humanity adequately in a nutritionally adequate manner. The history of agricultural biodiversity can be viewed as a series of key events, often labelled as revolutions - the Neolithic Revolution, the Columbian Exchange, the Industrial Revolution, the Green Revolution and even the more recent supermarket, health food and genomic revolutions. During the Neolithic period, humans started their transition from nomadic hunter-gatherers to sedentary farmers, which allowed the accumulation of surpluses, rapid population growth, the rise of cities and the development of civilization.