It is often erroneously believed that evolution is something that happened in the past. However, there is strong evidence that evolution is continuing at the present time, as plants face new selection pressures generated by human activities that destroy, damage, fragment and alter ecosystems. In a world grappling with anthropogenic climate change, such pressures are likely to increase, as human populations, presently about 6.5 billion, are projected to rise to 12.8 billion by 2050 (if fertility remains at present levels).

In human-influenced landscapes, two broad classes of plants are often recognised, based on their apparent success or relative failure. Thus, some species are ‘winners’ (crop plants, weeds, invasive plants etc.). Others, the endangered species, are ‘losers’ or ‘potential losers’, with extinction their likely fate. Put simply, some plant species appear to be at a selective advantage in changing ecosystems and their populations are stable or increasing, while others faced with the same selection pressures are declining and threatened with extinction. Traditionally, but with some honourable exceptions, these two facets of evolutionary change are treated as separate subjects in academic books and elsewhere. Here, the notion of winners and losers is considered as a single concept, as major insights emerge through such an approach.