The study led by Dr Yixiang Shan and Professor Colin Osborne in collaboration with the Autonomous University of Madrid and King Juan Carlos University and Wageningen University, examined how wild plants adapted to human exploitation, finding that early cultivation selected for plants with a significantly stronger competitive ability than their wild ancestors.
Published in Current Biology the findings show that the act of planting seeds in managed fields created a high-stakes environment. Over a period of 1,000 to 2,000 years, this process favoured plants that could outmanoeuvre their neighbours, leading to the development of "warrior" phenotypes in ancient landraces.
The research shows that early domesticated wheats were much stronger competitors for light and space in the field than wild varieties. This competitive edge was achieved through specific physical adaptations: larger, more upright leaves and a greater ability to maintain shoot growth even when crowded by other plants.
By using a functional-structural plant (FSP) model to simulate growth, the researchers identified that steeper leaf angles were the most influential trait. These upright leaves allowed domesticated plants to overtop their neighbours during the vegetative stage, capturing more sunlight and shading out rivals.
‘While evolution has favoured strong competitors, modern farming packs crops tightly into fields for high yields. This practice needs crops that are able to cooperate not compete, and has meant modern breeders needed to reverse the unhelpful effects of evolution.’ Professor Colin Osborne
However, the research also reveals a stark reversal in this evolutionary trend during the modern era. While ancient landraces were bred for aggression, modern "elite" durum wheats produced by selective breeding programmes have become less competitive. In contemporary farming, where herbicides and fertilisers are used to manage resources, breeders have favoured varieties with smaller leaves and shorter stems to ensure energy is directed toward grain production rather than fighting for space.
The findings indicate that the traits responsible for the success of wheat during early human history are often unsuitable for conventional modern agriculture. This shift highlights how the specific environment of the field - and the transition from ancient cultivation to modern industrial farming - has fundamentally reshaped the architecture and behaviour of one of the world's most important food crops.