Large precolonial villages in the Brazilian Cerrado practiced maize-based polyculture

For decades, researchers have debated the subsistence strategies of precolonial societies of the Brazilian Cerrado (tropical savanna): were they hunter-gatherers or intensive maize farmers, and in either case, how did they organize themselves and interact with the land they inhabited? This week, a study published in Science Advances provides the first large-scale direct evidence to answer these questions. The evidence shows that while some populations relied on diverse plants, maize farming played a central role for others. But rather than practicing intensive monoculture, these communities developed diversified maize-based polyculture systems.

“For many years, the Cerrado debate focused on two extremes: highly mobile foraging or intensive sedentary farming,” says Eliane Chim, lead author of the study. “Instead, we found that some societies depended heavily on maize grown within diversified agricultural systems capable of sustaining large villages. This fundamentally changes our understanding of Indigenous food production and settlement in central Brazil.”

The researchers analyzed stable carbon, nitrogen, and oxygen isotopes from the teeth and bones of more than 100 individuals recovered from 37 archaeological sites across the Cerrado, Caatinga and Atlantic Forest biomes. Combined with new radiocarbon dates from human bone collagen, faunal isotope baselines, archaeobotanical evidence and palaeoecological records, the study reconstructs diets across the region during the Late Holocene with chronological precision.

The isotope evidence shows that people associated with the open-air villages obtained a substantial proportion of their diet from maize, whereas contemporaneous populations living in nearby rock shelters consumed much more diverse foods and showed little evidence of intensive maize use. Because these groups occupied similar environments, the differences cannot be explained by ecology alone. Instead, they reveal the coexistence of distinct cultural traditions and economic strategies across the region.

“These results challenge broader ideas about how agriculture developed in tropical South America,” says Prof. Patrick Roberts, director of the Department of Coevolution of Land Use and Urbanisation at the Max Planck Institute of Geoanthropology. “Our findings show that maize was part of resilient polycultural food-production systems that combined domesticated crops with wild plants and local ecological knowledge.”

The findings also place the Cerrado alongside the Amazon as a major centre for understanding Indigenous innovation before European colonization.

“The Cerrado has often been overshadowed by the Amazon in discussions of precolonial land use,” says Prof. André Strauss of the Museum of Archaeology and Ethnology at the University of São Paulo (Brazil). “Our findings demonstrate that it was also a centre of innovation, where different societies developed distinct ways of interacting with one of the world's most biodiverse tropical landscapes.”

Beyond archaeology, the research contributes to understanding the long history of human influence on one of the world's richest tropical savannas, highlighting sustainable land-use strategies that helped shape Cerrado landscapes for centuries. These findings contribute not only to refining our understanding of past food production but also contribute to contemporary discussions on biodiversity conservation, Indigenous knowledge, and the long-term management of tropical ecosystems.

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Journal

Science Advances

DOI

10.1126/sciadv.aef7066 

 

Hasmonean history is combined with the enigma of the Qumran calendar

 New study by Prof. Eshbal Ratzon of Tel Aviv University

Hasmonean history is combined with the enigma of the Qumran calendar – to solve an ancient mystery of the Dead Sea Scrolls

• According to the study, the 364-day calendar, a crux of the dispute between the Qumran sect and Jerusalem, was actually used for a time by the Qumran community, but was abandoned when it began to drift away from the seasons, and relations with Hasmonean King Alexander Jannaeus improved.

A new study from Tel Aviv University proposes a solution to a historical mystery that has puzzled researchers for decades: Was the unique calendar of the Qumran sect, based on a 364-day year, ever used in practice, or was it merely a theoretical model?

The study hypothesizes that the calendar was indeed used by the sect in its early years, and even stood at the crux of the controversy that drove the sect to isolation in the desert. However, the calendar was later abandoned due to an inherent problem that made it impracticable over time, as well as warming relations with Hasmonean leadership under Alexander Jannaeus.

The study was conducted by Prof. Eshbal Ratzon of the Department of Jewish Philosophy and the Cohn Institute for the History and Philosophy of Science and Ideas at the Entin Faculty of Humanities. The paper was published in the Tarbiz Quarterly for Jewish Studies.

The Qumran calendar differed from the lunisolar calendar that served as a basis for Jewish life during the Second Temple period. It consisted of exactly 364 days - a number that is perfectly divisible by seven, and thus every year included 52 full weeks, and every holiday always fell on the same day of the week. For the Qumran sect, this reflected a perfect divine order. In the political sense, the calendar represented a rebellion against the political and religious leadership at the Temple in Jerusalem, which determined all significant dates. The sect believed that these dates had already been set by God during the Creation of the world, and humans must not interfere.

Yet the Qumran calendar's mathematical perfection created a serious difficulty: it diverged by one day and a quarter from the 365-day astronomical year. This difference may appear negligible, but it accumulates rapidly. For instance, if the Qumran calendar was used for twenty years, the festivals would shift by almost four weeks relative to the seasons. After several decades, a spring festival would end up being celebrated in winter, or even in the fall. For a community that regarded festivals as agricultural events connected to the harvest, first fruits, and seasons of the year, this posed a fundamental problem.

To understand the significance of the gap, one can compare the calendar to a clock that deviates by one minute every day. At first, no one notices the problem, but after months and years, such a clock no longer represents reality. The study explains that this is exactly what happened to the Qumran calendar: while ideal from a conceptual and mathematical perspective, over time it drifted further and further away from the natural cycles it sought to govern.

Over the past decades, researchers have proposed various solutions to this enigma. Some maintained that the Qumran sect periodically added days or weeks to its calendar, while others claimed that the calendar had never actually been used in the real world, serving only as a theoretical framework. Prof. Ratzon argues that neither option is supported by the Dead Sea Scrolls. According to her study, the evidence indicates that the calendar was regarded by the sect as a key component of their religious identity and a major point of contention with the Jerusalem establishment.

The study notes that almost twenty of the scrolls found in Qumran deal with calendars and astronomy - an exceptional number that attests to the topic's immense importance for the community. The Book of Jubilees, a central work in the Qumran library, fiercely attacks the prevailing lunar calendar, presenting the 364-day calendar as the original calendar received by Moses on Mount Sinai.

Based on this body of evidence, Prof. Ratzon proposes a new historical reconstruction: she contends that the Qumran calendar was actively used during the sect's formative days in the second century BCE, exacerbating its conflict with the religious leadership in Jerusalem. However, as the years went by, the calendar's accumulating digression from the seasons could no longer be ignored. In addition, the sect's relations with the ruling Hasmonean dynasty warmed during the reign of Alexander Jannaeus, who supported a halacha similar to their own and opposed the Pharisaic leadership. This enabled the Qumran sect to relinquish their previously adamant position and adopt the more practical calendar used at the Temple. They retained their own calendar as a theoretical concept that had been valid at the time of Creation and might be used again in the End of Days.

Prof. Ratzon concludes: "The Qumran calendar has long been regarded as one of the Qumran sect's defining features, but also as one of the most baffling mysteries of the Dead Sea Scrolls. This study proposes an alternative for the seeming contradiction between a functional calendar and a theoretical one. It is quite possible that the calendar was in fact used for a certain period of time, but then, losing its practical role due to both inherent problems and political changes, became a religious ideal and a symbol of identity. This would explain both its centrality in the Qumran scrolls and its gradual disappearance from historical reality."

Unusual to share a grave with close relatives in the Middle Ages

 When archaeologists find adults and children buried together in medieval graves, it is often assumed that they were members of the same family. A new study from Stockholm University in Science Advances suggests otherwise.

Researchers at Stockholm University analysed DNA from 142 individuals dating from the late Viking Age and Middle Ages, including more than 60 children and adolescents buried in multiple graves at sites in Sigtuna, close to Stockholm, Västerhus in Jämtland, and Fjälkinge in Skåne.

The results show that close biological relatives were surprisingly rare among people buried in the same grave, even at cemeteries where high levels of kinship could be detected.

”We often assume that adults and children sharing a grave were parents and children or other close family members. In most cases, that was not what we found,” says Maja Krzewińska, Centre for Palaeogenetics, Department of Archaeology and Classical Studies, Stockholm University, lead author of the study.

Instead, the researchers’ findings suggest that factors other than close family ties often influenced who was buried together.

”Archaeologists have debated the relationships between people buried together in this type of grave for a long time. Ancient DNA has finally given us the tool we have been waiting for to test these interpretations directly,” says Anna Kjellström, researcher at the Department of Archaeology and Classical Studies, Stockholm University.

The study also sheds light on the lives of children in early Christian Scandinavia. By using ancient DNA, the researchers could determine the biological sex of children who were too young to be identified osteologically. Boys and girls were often buried according to the same cemetery rules as adults. For example, at Västerhus, where men and women were generally buried on different sides of the churchyard, boys and girls followed the same pattern. This suggests that gender identity was recognised early in life.

”The children were not treated as a separate category. In death, they appear to have been treated according to the same social and religious principles as adult men and women,” says Anders Götherström, Professor of Molecular Archaeology, Centre for Palaeogenetics, Department of Archaeology and Classical Studies, Stockholm University.

The study also identified a remarkable family from the medieval cemetery at Västerhus. One woman, known to researchers as Lady 56, could be linked through DNA to several relatives buried in the churchyard, including her parents, her brother, and two daughters. Yet her story extends far beyond Jämtland.

Buried with her was a scallop shell, a rare object in a medieval Scandinavian grave and a well-known symbol of pilgrimage to Santiago de Compostela in northwestern Spain. The find suggests that she completed one of medieval Europe’s most famous pilgrimages, travelling thousands of kilometres across the continent to the far edge of Christian Europe before returning home. Lady 56 died before the age of 30. Her parents, brother, and daughters were also buried in different part of the same cemetery in Jämtland.

The study demonstrates how archaeogenetics can advance our understanding of medieval society, revealing not only biological relationships but also the social worlds in which people lived, organised their communities, worshipped, and were ultimately laid to rest.

The article “Equal in death: Ancient genomic analysis of children’s early Christian burials” was published in Science Advances, DOI: 10.1126/sciadv.aeb8588

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Journal

Science Advances

DOI

10.1126/sciadv.aeb8588 

Evolution of the Pictures of Tilling and Weaving, Southern Song Dynasty to the Qing Dynasty

 Gengzhitu 耕織圖 (Pictures of Tilling and Weaving) functions as a cultural artifact representative of agrarian civilization and dynastic governance, fulfilling dual roles as a vessel for agricultural knowledge and a motivational tool for farming practices. 

Over the course of its transmission from the Southern Song Dynasty to the Qing Dynasty, a fascinating relationship emerged between the practical knowledge imparted by the Pictures of Tilling and Weaving and its role as a motivational tool for agricultural practices, creating a dynamic interaction akin to a seesaw effect. The fluctuation between the “form” and the “knowledge” of the Pictures of Tilling and Weaving provides valuable insights into the characteristics of scientific knowledge dissemination in traditional societies. 

This paper investigates the propagation and transformation of the Pictures of Tilling and Weaving, with a particular emphasis on the changes in its acknowledged intellectual merit and political importance throughout various historical epochs. The objective is to deepen comprehension of the interplay between the “form” and the “knowledge” in the conveyance of traditional agronomic knowledge as illustrated by the pictures.

Why the Polynesians suddenly sailed east

 Major drought forced people to migrate across the Pacific beyond Samoa and Tonga and towards the Americas, scientists have discovered.

With the new live action Moana film hitting cinemas on Friday [10 July], a team of geographers and climate scientists from the Universities of Southampton and East Anglia has discovered the true history of the tale.

Moana tells the story of a young Polynesian girl who leaves her threatened home island to sail past its barrier reef to save her island and its people.

The story is built on a period of history called the ‘Long Pause’. Around 3,000 years ago the ancestors of modern Polynesians arrived in Samoa and Tonga, and for 1,700 years they did not sail further east into the Pacific. Then around the years 900-1050 AD, they voyaged east and within 250 years settled the remaining island archipelagos of the South Pacific including Tahiti, Hawai’i and the continental Americas, in what was the greatest seafaring migration in history.

David Sear, Professor of Physical Geography at the University of Southampton and lead author of the study, said: “We have confirmed the theory that the end of the Long Pause coincided with a period of mega drought in the homeland islands of Samoa and Tonga – and also a period of increasing rainfall in the receiving islands. As they headed east, they found wetter islands with nobody on them.

“There was a huge explosion of migration, and within 250 years they had landed and settled every little dot in the South Pacific, from tiny coral atoll islands to larger lands. It was a very rapid process.”

Analysing samples from mud

The research team analysed mud samples from deep beneath swamps and lakes in Samoa, Tonga, French Polynesia and the Cook Islands.

They used ‘biochemical fossils’ produced by freshwater algae and leaves to measure the isotopic ratio of hydrogen to determine historic rainfall levels. This data consistently showed evidence of a severe and prolonged drought just before and during the period of migration.

“Hydrogen in rainwater contains heavier and lighter isotopes, the proportion of which is determined by the amount of precipitation in the tropics– which we were able to analyse in the mud,” explained Dr Mark Peaple, research fellow in paleoclimate at the University of Southampton, who undertook the geochemical analysis. “So analysing the ancient biomarker fossils we can reconstruct rainfall changes from thousands of years.”

When the Long Pause ended, it was the driest period in the last 2,000 years for these islands, so the islands’ populations were forced to move.

Climate modelling

The scientists also used climate modelling to understand the drivers of the dry conditions found in Samoa and Tonga.

Manoj Joshi, Professor of Climate Dynamics at the University of East Anglia, led the climate modelling. He said: “Our research shows that changes in sea surface temperatures across the Pacific Ocean over many decades drove an eastward shift in the vast rain belt that lies over this whole region, causing the dry conditions found in Samoa and Tonga.

“The climate changes we identified would have transformed daily life on these islands. Reduced rainfall would have affected freshwater availability, food production and the resilience of communities, creating powerful incentives for people to seek opportunities elsewhere.”

Dan Skinner, research fellow at the University of East Anglia who undertook climate modelling experiments said: “We now know that the climate – and specifically a period of severe drought for many years, even decades – is a definite factor in forcing this impressive migration.

“These findings illustrate how sensitive human societies can be to long-term changes in climate. Even highly skilled and adaptable communities may be driven to undertake extraordinary journeys when environmental conditions deteriorate over many years.”

Professor Sear added: “Other factors would also have contributed to the tipping point that made the costs of sailing into the eastern Pacific worth risking. There was an increasing population, meaning resources had to stretch further. Also, they had probably developed advanced sailing technology for their voyaging canoes by this point, adapting from U to V-shaped hulls and improving their rigging, which meant they could sail into the wind, which is predominantly east to west across the South Pacific.”  

The research is published in the Journal of Pacific Archaeology.

Instead of only eating maize directly, early farmers were also eating animals that ate maize

 Maize, or corn, is a major dietary staple in Maya communities past and present because of its reliability, potential for surplus and suitability as both food and fodder. It became so important to ancient Mesoamerican communities that it even became central to many of their religious beliefs, and arguably, they built their societies on it; yet maize has a major nutritional limitation. 

Although it is an excellent source of carbohydrates, it is surprisingly low in lysine, an essential amino acid that serves as a crucial building block of protein. Without enough lysine, people cannot build and maintain body tissues like muscles and bones. Previous work suggests that as much as 70% of the protein in ancient Maya diets was ultimately derived from maize. But there is a problem: an adult would have to eat over 13 pounds of dry maize kernels (nearly 40 pounds of fresh maize) every day to get enough lysine, an impossible amount. 

So how, then, did early maize farmers survive and thrive as maize consumption was rapidly increasing? 

This conundrum is why new research by Nadia Neff, a doctoral candidate in archaeology at the University of New Mexico, is groundbreaking. Her paper, titled Nutritional Adaptations to Early Maize Cultivation: Earliest Isotopic Evidence of Maize-Based Animal Provisioning in the Neotropics, has been published in the AAAS Science Advances Journal and shows how ancient farmers used innovative methods to adapt their primary food source to meet their dietary needs. Using cutting-edge amino acid isotope analysis and statistical modeling, Neff and team traced individual amino acids from maize through animals and into ancient human diets spanning more than 5,000 years in Central America. 

The results of their study show that maize-eating animals, such as turkeys, likely acted as biological “protein concentrators.” Because these animals can eat far more food relative to their body size than humans, they can obtain all the lysine they need from maize alone. When people eat those animals, they are essentially accessing concentrated maize-derived lysine converted into high-quality animal protein.

“What we found is that these early communities weren’t simply adopting agriculture for calories,” said Neff. “They were actually actively engineering their food systems to solve different nutritional problems.” 

According to Neff and her faculty adviser, Keith Prufer, their findings suggest that maize cultivation and animal management developed together much earlier than previously recognized. Instead of viewing maize farming and animal management as separate innovations, their study shows that they likely formed complementary parts of a greater adaptive food system as early as 6,100 years ago. 

Her findings are even more interesting because this study was not what she originally set out to find when she first began data collection. She conducted a few analyses examining the carbon stable isotope ratios in the amino acids of bone collagen and was confused by how high the lysine values she measured were, given how little lysine there is in maize. 

“It’s just not possible for people to eat enough maize directly to result in such high carbon stable isotope ratios in their lysine,” she said. Prompting her to look for other potential explanations for the patterns she was seeing. 

By collaborating across multiple disciplines, including archaeology, biochemistry, ecology, nutrition science and observations of modern Maya farming practices, Neff and her team were able to demonstrate that instead of only eating maize directly, early farmers were also eating animals that ate or were fed maize, thereby “concentrating” maize-derived lysine as it moved up the food web, reconciling the stable isotope ratios she had measured, and gaining a deeper understanding of this ancient society.

Neff has been working as a bioarchaeologist on Prufer’s archaeological project, Research into the Origins and Organization of Tropical Societies (ROOTS), traveling each year to rockshelters in southern Belize to conduct excavations. 

Working with local communities and NGOs, they carefully excavate sites dating back 10,000 years, and at UNM’s Human Ecology and Radiocarbon Lab at the Center for Stable Isotopes, Neff performed her analyses to study the isotopic signatures in individual amino acids from human and turkey bone collagen and modern plants. 

“We used amino acid isotope analysis because it gives us a much more detailed picture of human nutritional biology than looking at bone collagen as a whole,” Neff explained. This allowed the team to more closely examine how people in the past grew, prepared and ate food. 

UNM’s Center for Stable Isotopes is one of the few labs in the country capable of performing this type of analysis. 

“Nadia is building on decades of our work on early diets in the American tropics and significantly expanding our understanding of these ancient community practices in the Maya communities,” Prufer, the director of the Human Ecology and Radiocarbon Lab and core faculty at the Center for Stable Isotopes, explained. “Our research even shows that maize was adapted much earlier than previously believed.”

Beyond rewriting the history of ancient Maya diets, Neff’s work shows the power of amino acid isotope analysis to reveal relationships hidden inside ancient food webs. By showing how past societies built nutritionally resilient food systems, her work also offers new perspectives on modern discussions of food security, agricultural sustainability and overall human nutrition.

To learn more about this research, visit the AAAS Science Advances website or email Neff directly at ncneff@unm.edu. 

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Did elephant energetics decide Hannibal’s Alpine crossing route?

 

A new analysis sheds light on the most likely route for the Carthaginian general’s famous crossing of the Alps. The study, led by the University of Oxford and iDiv/Friedrich Schiller University Jena, reveal that the Col de la Traversette would have been the least energy-intensive route. The findings have been published today (July 6, 2026) in Proceedings of the National Academy of Sciences.

The study provides a novel perspective on one of history’s most famous military journeys: Hannibal’s route across the Alps in 218 BC with an army of 40,00 men, 7,000 horses and 37 war elephants. The researchers applied a bioenergetic approach to evaluate competing theories about Hannibal's crossing by focusing on the energy demands of the journey, particularly for the army’s war elephants.

The findings support the Col de la Traversette as the more likely route, rather than the Col du Clapier, which previously was the leading candidate. Using route modelling and elevation data, the team estimated the energy cost of each possible Alpine crossing. This drew on modelling methods based on contemporary African elephants which estimate the energy costs of movement based on body mass and terrain slope.

The results suggest that the Col de la Traversette would have been the shortest and most energetically efficient route, with a total cost for the whole army of 5.42 TJ (10^12 joules). The route ranked second, at 6.02 TJ, crossed the Alps at the Col de Montgenèvre and reached the Po Valley from Susa. The Col du Clapier route was ranked third at 6.28 TJ, while the route crossing Col du Mont Cenis was the least efficient option at 6.45 TJ.

Compared with the Traversette route, the routes via Col de Montgenèvre, Col du Clapier and Col du Mont Cenis would have required 11%, 16% and 19% more energy for the army as a whole, respectively.

The team’s results also underline the biological challenge of moving the army through the mountains. On the Traversette route, the men would have lost 19% of their body fat reserves during the crossing, potentially explaining their high mortality. Surprisingly, the model suggests that the war elephants would have fared better, only losing 4% of their reserves. Such high energy reserves likely explain why many, if not most, elephants survived the crossing.

The study demonstrates how movement ecology can offer new perspectives on Hannibal's decision-making, and how interdisciplinary research can shed new light on historical events by combining ancient sources with modern analytical methods.

Study co-author Professor Fritz Vollrath (Department of Biology, University of Oxford, and Save the Elephants UK) said: “Applying insights gained from studying the energetics of African elephants in Kenya is bringing a novel dimension to the longstanding debate over Hannibal's Alpine crossing.”

Co-author Dr Emilio Berti (German Centre for Integrative Biodiversity Research (iDiv) and the Friedrich Schiller University Jena) added: “The question of Hannibal's exact route has been debated for generations. The new analysis does not eliminate all ambiguity, but it does strengthen the case for the Traversette route by demonstrating that it would better accommodate the demands of moving a large army that included elephants through extremely difficult alpine terrain.”

It is still unclear why exactly Hannibal used elephants during the Punic wars. Potentially, he intended them to provide a tactical element of surprise in his first battles against the Romans. Alternatively, he may have hoped they would awe and help recruit the Celts of Northern Italy to his side.

 URL: https://www.pnas.org/doi/10.1073/pnas.2612764123.