Applications of ecological principles to agriculture are usually developed within the discipline of agroecology, a term first used by the Russian agronomist Basil M. Bensin in the late 1920s (Wezel et al., 2009). Traditionally, however, agroecological research has focused on ecology, socioeconomics and sustainability of productivity. It is only recently that more explicit evolutionary approaches have been applied in this discipline, so much so that even articles published as recently as 2003, devoted to the issue of scaling – including time scaling – in agroecology, do not explicitly address evolutionary dynamics and processes (e.g. Dalgaard et al., 2003). Nevertheless, such a situation is being redressed in more recent work, where a new emphasis on evolutionary agroecology is steadily surfacing (Thrall et al., 2010; Weiner et al., 2010). However, the role of evolution in agriculture has been central since the very beginning of this practice: agriculture itself is, indeed, a long coevolutionary process (e.g. Hart, 1999). In this chapter, we aim to briefly review some major applications of evolutionary principles to agriculture and in the ‘Looking forward’ section we will endeavour to suggest some future directions in evolutionary agroecology. Agriculture has been called ‘the greatest ecological experiment on Earth’ and has also been described as always being in a state of ‘tension’. We are now beginning to realise more fully how the ‘experiment’ and the ‘tension’ implicate evolutionary processes as well as ecological ones.

The main issues

The fundamental premise behind almost all agricultural systems worldwide is that ecological succession is halted. In arable and vegetable cropping, for instance, annual plants can dominate the landscape. Virtually all interspecific competition is reduced to a minimum; this includes weed management within and around the crop and sometimes the reduction or removal of largely woody field margin plants. Similarly, farming attempts to reduce any negative impacts of evolutionary processes on the farming activity. These may include the development of insecticide resistance in insect pests, fungicide resistance in fungal plant diseases and weed resistance to herbicides. As well as attempting to reduce the impacts of evolutionary processes, farming also largely ignores the benefits which can accrue from a more complete understanding of the role that a knowledge of evolution can play in helping to make agriculture more ‘sustainable’. Examples of some of the evolutionary processes which are either ignored or restricted in some way are given below.