The findings, published in the Proceedings of the National Academy of Sciences, challenge a central assumption about how cereal domestication began. Researchers studying charred barley and emmer wheat grains from the Early Neolithic sites of el-Hemmeh and Sharara in the southern Levant found that the plants still possessed fully wild characteristics during the earliest phases of the Pre-Pottery Neolithic. Their ears had brittle rachises, the structures that naturally break apart when mature, allowing seeds to disperse in the wild. There was no evidence of the tough, non-shattering rachis that later became one of the defining features of domesticated cereals.

The absence of non-shattering forms is significant because a tough rachis makes harvesting far more efficient. In wild cereals, the rachis fractures as the plant ripens, scattering seeds before people can collect them. A mutation that keeps the grains attached would have offered major advantages to human harvesters and could then have spread through repeated cultivation and replanting. Researchers have therefore often treated the appearance of non-shattering cereals as a key marker of domestication. Grain size, by contrast, has frequently been interpreted as an earlier signal that people were already selecting plants through cultivation.

At el-Hemmeh and Sharara, however, grain size told a more complicated story. Barley and emmer wheat remained morphologically wild, yet their grains varied dramatically. Some were as small as typical wild cereals, while others fell within the size range commonly associated with domesticated plants. If large grains were the product of genetic selection caused by systematic tillage, the researchers expected to find other evidence of intensive cultivation. Instead, the ecological evidence pointed toward relatively low-disturbance environments.

The team examined the weed species preserved alongside the cereal remains. Weeds are valuable archaeological indicators because different plants thrive under different environmental conditions. Species associated with heavily tilled or frequently disturbed soils were not dominant in the assemblages from these early sites. This weakened the argument that repeated ploughing or intensive soil preparation had already created strong selection for larger seeds. The researchers began looking for another explanation for the striking variation in grain size.

Their answer came from stable carbon isotope analysis. Carbon exists in several naturally occurring forms, or isotopes, and plants incorporate these isotopes in ways that are influenced by their growing conditions. In cereals, the stable carbon isotopic composition of a grain can reflect the balance between carbon uptake and water loss during photosynthesis. When plants experience water stress, changes in gas exchange through their leaves alter the carbon isotope signal recorded in their tissues. By measuring this signal in ancient grains, scientists can reconstruct aspects of the moisture conditions under which the plants grew.

The results showed a strong relationship between grain size and water availability. Barley grains that reached domestic-sized dimensions had carbon isotope values indicating that they developed under wetter conditions. Smaller, wild-sized grains carried signatures consistent with considerably drier growth environments. The difference suggests that environmental moisture, rather than inherited genetic change, was responsible for much of the early increase in cereal grain size. In other words, the same wild plant population could produce grains of very different sizes depending on the conditions it experienced during development.

This phenomenon is known as developmental plasticity: the ability of a single genotype to produce different physical traits in response to the environment. It is widespread in plants and can affect characteristics such as height, leaf area, flowering time and seed production. In the Early Holocene southern Levant, developmental plasticity may have created the visual impression that cereals were already becoming domesticated. People collecting and replanting the largest grains might eventually have generated genetic selection, but the initial size increase itself appears to have been ecological rather than evolutionary.

“Environmental conditions provided a much better explanation for the observed variation in grain size than genetic selection under tillage,” said Dr Jade Whitlam of the University of Oxford, who led the study. The researchers propose that genetic selection for larger grains may have occurred later than previously thought, perhaps after selection for non-shattering rachises had already begun. This reverses the sequence often assumed in models of domestication and places greater emphasis on the complex interaction between climate, plant biology and human harvesting practices.

The study also reframes the origins of agriculture as a gradual process of niche construction rather than a sudden decision to domesticate plants. Early communities altered their relationship with wild vegetation through harvesting, protection, transport and repeated use of particular landscapes. These practices may have changed plant populations long before crops displayed unmistakable domestication traits. By combining archaeobotany, weed ecology and stable isotope evidence, the researchers argue that the first steps toward agriculture were not necessarily driven by deliberate genetic engineering of crops, but by prolonged human management operating within a variable environment. The result is a more nuanced picture of farming’s origins—one in which climate could temporarily make wild cereals look domesticated before their genomes caught up.

Subject of Research: The environmental and biological processes that influenced cereal grain size and plant domestication in the Early Holocene southern Levant.

Article Title: Developmental plasticity under human management shaped cereal evolution prior to domestication in the Early Holocene southern Levant

News Publication Date: 4-Aug-2026

Web References: https://www.eurekalert.org/multimedia/1146086

References: Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2535274123

Image Credits: Jerome Poulalier, www.jerome-poulalier-photography.com

Keywords: Archaeology, archaeobotany, cereal domestication, agriculture, Neolithic, Early Holocene, southern Levant, barley, emmer wheat, stable carbon isotopes, developmental plasticity, plant evolution, climate, hunter-gatherers

This new research delves deeply into the Linear Pottery Culture, the initial wave of Neolithic farmers who settled Central Europe around 5,400 to 4,900 BCE. These pioneering agrarians predominantly cultivated emmer and einkorn wheats—ancient spelt varieties requiring labor-intensive dehulling processes to remove outer husks before consumption or processing. While previous scholarship acknowledged the emergence of naked wheat and barley in later Neolithic phases, this study uniquely refines the chronological framework and unravels the agricultural mechanisms underpinning this crop diversification. The findings consequently disrupt prior assumptions by pinpointing the early onset of such innovations at the beginning of the Middle Neolithic period, approximately between 4,900 and 4,500 BCE.

Central to the study’s methodology was the comprehensive collection and statistical analysis of archaeobotanical macroremains, primarily charred grain fragments, unearthed from 72 Neolithic settlements within the Rhineland archaeological zone. These charred remains, preserved in settlement pits, serve as invaluable proxies for reconstructing ancient farming practices and crop diversity. Employing advanced multivariate statistical techniques, the research team parsed complex datasets to detect distinct agricultural phase shifts and nuanced changes in crop spectra over time. This quantitative approach allowed for unprecedented differentiation between Neolithic phases, illuminating temporal trends otherwise obscured in qualitative assessments.

One of the study’s pivotal revelations was that the Middle Neolithic agricultural transition occurred earlier and more abruptly than traditionally documented. By integrating new cereal grains such as naked wheat, which circumvented the dehulling step, farmers not only optimized labor efficiency but also augmented the robustness and flexibility of their cultivation systems. This diversification facilitated the simultaneous planting of both winter and summer crops, expanding the agricultural calendar and enabling exploitation of a broader array of ecological niches and soil types. These adaptations collectively signify an emergent sophisticated understanding of agroecology among these prehistoric communities.

Diversity analysis within the dataset revealed a crescendo in cereal variety cultivation around 4,350 BCE, marking a zenith in agricultural heterogeneity. Following this peak, a discernible contraction in crop diversity suggests the onset of further transformative processes within the farming systems. This pattern indicates a possible strategic reorganization of food production, likely dovetailing with increasing specialization in other subsistence activities, such as intensified livestock herding. Preliminary evidence points toward a reinforcement of cattle farming during this subsequent phase, underscoring a complex interplay between crop cultivation and animal husbandry in Neolithic economies.

The research outcomes underscore the remarkable adaptability of early farmers to regional environmental constraints. In geographically challenging areas characterized by poorer soils or harsher climatic regimes, agriculturalists selectively cultivated cereal species with elevated resilience or yield potential under such conditions. Such strategic crop choice highlights a profound localized ecological knowledge and an ability to tailor food production strategies to microenvironmental variations. It marks a departure from previous views that depicted Neolithic agriculture as a uniform, static practice, emphasizing instead dynamic and context-sensitive management.

This study not only enriches archaeological narratives but also offers broader implications for understanding human-environment interactions and the evolution of sustainable agricultural practices. The adaptive flexibility evidenced by these early farming communities parallels contemporary concerns regarding climate variability and agricultural resilience. Insights into how prehistoric societies balanced crop diversity, labor investment, and ecological constraints may inform modern agronomic research focused on crop diversification and soil management.

Technically, the application of multivariate analysis to archaeobotanical macroremains represents a methodological advance, enabling researchers to interpret complex interactions between agricultural practices and environmental factors quantitatively. This statistical framework facilitates the identification of subtle temporal shifts in cultivation patterns that traditional typological or descriptive methods might overlook. The integration of multiple scientific disciplines—including archaeobotany, dendroarchaeology, and zooarchaeology—further bolsters the robustness of interpretations by cross-validating findings through diverse lines of evidence.

The project’s success hinged upon extensive collaboration across scientific domains and institutions, demonstrating the value of interdisciplinary approaches in excavating the past’s complexity. The German Research Foundation-funded initiative exemplifies how pooling expertise in vegetation history, prehistoric archaeology, and statistical modeling can transform fragmentary archaeological data into comprehensive reconstructions of ancient human lifeways. As the research continues to explore late Neolithic transformations, ongoing analyses are expected to yield further revelations about the interplay of agricultural evolution and socio-environmental dynamics.

In sum, this pioneering investigation reframes the narrative of Neolithic agriculture in Central Europe, illustrating how early farmers were not merely passive cultivators but active innovators. By incorporating new cereal species, diversifying crop types, and adapting cultivation strategies in response to environmental variability, these communities laid foundational principles for sustainable food production. Their legacy resonates profoundly in contemporary dialogues about agricultural resilience and ecological stewardship, reiterating that the seeds of innovation were sown thousands of years ago in the fertile soils of the Rhineland.

Subject of Research: Early Neolithic agricultural development and crop diversification in the Rhineland region through archaeobotanical and multivariate statistical analysis.

Article Title: Dynamics of early agriculture – multivariate analysis of changes in crop cultivation and farming practices in the Rhineland (Germany) between the 6th and early 4th millennium BCE

News Publication Date: 25-Sep-2025

Web References: http://dx.doi.org/10.1016/j.jas.2025.106369

Image Credits: Tanja Zerl, University of Cologne

Keywords: Neolithic agriculture, crop diversification, archaeobotany, Linear Pottery culture, emmer wheat, einkorn wheat, naked wheat, barley, multivariate analysis, prehistoric farming, Rhineland archaeology, early European farming practices, agricultural resilience