Rosa Rubicondior: Refuting Creationism - How Humans Caused 'Warrior' Wheat to Evolve.

Early farming unintentionally bred highly competitive "warrior" wheat, study finds | Biosciences | The University of Sheffield

One of the more embarrassing questions you can ask a creationist is this: if an omniscient, perfect god created all living things for the benefit of humankind, as the biblical creation myth claims, why have humans had to modify almost all our domesticated animals and cultivated crops to make them fit for purpose? In many cases, we have altered them so extensively that they are barely recognisable as the same species as their wild ancestors.

The story of how humans domesticated wild species and gradually modified them is, in effect, a textbook example of evolution in progress. Sometimes this happened through conscious selective breeding, but often it was an unintended consequence of domestication itself. Wheat, for example, evolved grains that were more firmly attached to the stalk. This meant fewer grains were lost when harvested and carried back to camp for communal use, so the plants whose seeds stayed attached were more likely to have those seeds planted again, whether deliberately or accidentally, around early hunter-gatherer encampments.

Another example in wheat is the evolution of taller plants with more upright leaves. As humans began planting wheat more densely, they created an environment in which the more aggressive plants literally overshadowed their neighbours and captured a greater share of the sunlight. In this struggle for existence, the plants best suited to the human-made environment were the ones most likely to survive and become the parents of the next generation.

That is the conclusion of a research group led by Dr Yixiang Shan and Professor Colin Osborne of the University of Sheffield, working in collaboration with colleagues from the Autonomous University of Madrid, Rey Juan Carlos University in Spain, and Wageningen University in the Netherlands. Their findings are published in Current Biology.

Background^ the origins and cultivation of wheat.

One of the first domesticated crops: Wheat was among the earliest plants brought under cultivation, beginning more than 10,000 years ago in the Fertile Crescent of the Middle East. Evidence points especially to south-eastern Anatolia, including the Karacadağ region of modern Turkey, as a key centre in its early domestication. [1.1]
From wild grass to crop plant: Early domesticated wheats were derived from wild einkorn and wild emmer. Domestication favoured traits useful to humans, especially a non-brittle rachis — in other words, ears that held onto their grains instead of shattering and scattering them before harvest. Other domestication traits included larger seeds, larger leaves, reduced dormancy and greater above-ground growth.
Bread wheat is a hybrid: Modern bread wheat did not arise in a single simple step. It ultimately emerged when a domesticated tetraploid wheat hybridised with the wild grass Aegilops tauschii, producing the hexaploid wheat (Triticum aestivum) that now dominates world production. Durum wheat is tetraploid; bread wheat is hexaploid. [1.1]
How cultivation drove evolution: Wheat was not merely tamed; it evolved under human influence. Repeated harvesting and sowing favoured plants whose grains stayed attached long enough to be collected. Later, dense planting created new selection pressures, favouring traits such as taller growth and more competitive leaf arrangements. In other words, farming itself became an evolutionary force.
Its spread across the world: From its Near Eastern origins, wheat spread west through Anatolia into Greece by about 8,000 years ago, then across Europe, reaching Britain by roughly 5,000 years ago. It also spread east through Iran into Central Asia and China, and was later taken to the Americas and Australia. [2.1]
Why wheat became so important: Wheat is unusually adaptable. It grows across a wide range of climates, from sea level to high elevations, and under varied rainfall conditions. That adaptability, combined with its usefulness for making bread, pasta, couscous and other staple foods, is why it became one of the world’s most important crops. Today, bread wheat accounts for the great majority of global production, with most of the rest being durum wheat. [3.1]

They are also explained in a University of Sheffield School of Biosciences news item:

Early farming unintentionally bred highly competitive "warrior" wheat, study finds
An evolutionary ‘arms race’ for light and space led to the early domestication of wheat, according to new research that could offer fresh insights into crop design.
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 P. Osborne, corresponding author
Plants, Photosynthesis and Soil
School of Biosciences
University of Sheffield
Sheffield, UK.

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.

Publication:
Shan, Yixiang; Gómez-Fernández, Alicia; Evers, Jochem; Freckleton, Robert P.; Jones, Glynis E.M.; Milla, Ruben; Osborne, Colin P.(2026)
Evolution of competitiveness during wheat domestication
Current Biology 36(5), 1338.e4. https://doi.org/10.1016/j.cub.2026.01.061

Highlights

Domesticated wheat plants are stronger competitors than their wild relatives
Stronger competitive ability evolved early during the domestication process
Competitiveness increased through larger, steeper leaves and apical dominance
Modern wheat breeding has weakened competitiveness for high-density planting

Summary
Crop domestication involved adaptation of wild plants to human exploitation,^1,2,3,4 but the underlying selection mechanisms remain unclear.^2,4 Archaeological evidence from the best-studied regions shows domestication occurring across a diffuse region and protracted period of at least 1,000–2,000 years,^2,5,6,7 consistent with a co-evolutionary process.^2,3 For seed enlargement, both theory^2,6,8,9,10 and empirical evidence^11,12,13 indicate an unintentional evolutionary mechanism, potentially acting via an ecological process such as competition,^14,15,16 but this remains unproven. Here, we used real and virtual experiments to test the hypothesis that cultivation selected for stronger competitive ability in wheats. First, we compared three independent domestication events across wheat species, showing that domesticated landraces were stronger competitors than their wild counterparts. Model simulations reproduced this finding, showing that competitiveness increased through larger, more erect leaves and greater apical dominance. A second experiment compared wild, landrace, and elite durum wheats, finding that stronger competitiveness arose early during domestication but has been reversed by modern breeding. Simulations showed that weaker competitiveness in modern varieties arose from smaller leaves and shorter internodes. Our work indicates that competition selected for domestication traits responsible for wheat canopy growth and architecture, resulting in competitive landrace phenotypes unsuitable for conventional modern agriculture.

Graphical abstract

Shan, Yixiang; Gómez-Fernández, Alicia; Evers, Jochem; Freckleton, Robert P.; Jones, Glynis E.M.; Milla, Ruben; Osborne, Colin P.(2026)
Evolution of competitiveness during wheat domestication
Current Biology 36(5), 1338.e4. https://doi.org/10.1016/j.cub.2026.01.061

© 2026 Cell Press (Elsevier Inc.)
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.

What this study shows, yet again, is that evolution is not some mysterious process that happened only in the remote past and then stopped. It is an observable, testable process that continues wherever living things reproduce, vary and encounter new selection pressures. In this case, those pressures were not imposed by changing climate, predators or disease, but by human activity itself. Simply by harvesting, sowing and growing wheat in dense stands, early farmers created conditions in which certain variants left more descendants than others. That is evolution in action, whether creationists like it or not.

It also poses an awkward problem for the childish notion that all living things were perfectly designed from the outset for human use. If wheat was specially created for our benefit, why did it need to be reshaped by generations of unconscious selection before it became a truly effective crop? Why were its wild ancestors not already equipped with the traits that would make them most useful to us? The answer, of course, is that wheat was not handed to humanity as a finished, purpose-built product. It was a wild grass, and like every other domesticated plant or animal, it was modified over time by entirely natural processes.

For science, this is no surprise. The Theory of Evolution predicts exactly this sort of gradual change under selection, whether that selection is imposed by nature or by human beings. For creationism, however, it is just one more example of reality refusing to conform to mythology. Far from supporting the fantasy of a perfect, fully formed creation designed with humans in mind, the evidence shows that humans have had to mould wild species into forms that better serve our needs. The history of wheat is not a story of supernatural design, but of descent with modification under selection.

And that, once again, is the difference between science and superstition. Science follows the evidence wherever it leads and produces explanations that fit the facts. Creationism starts with a myth and then has to ignore, deny or misrepresent the evidence when the facts contradict it. Wheat, one of the very foundations of civilisation, turns out to be yet another witness for evolution and yet another problem for those who insist that ancient folklore is a better guide to reality than the evidence itself.

Advertisement

Amazon