Excavated dolmen in Sweden one of the oldest in Scandinavia

The first analysis results now confirm that the grave in Tiarp is one of the oldest stone burial chambers in Sweden. "It's an early grave which dates to the Early Neolithic period, about 3500 BCE," says archaeologist Karl-Göran Sjögren. The researchers also noted that some parts of the people buried in the grave are missing, such as skulls and thigh bones, posing intriguing questions for archaeologists.

Last summer, archaeologists from Gothenburg University and Kiel University excavated a dolmen, a stone burial chamber, in Tiarp near Falköping in Sweden.

The archaeologists judge that the grave has remained untouched since the Stone Age.

However, the odd thing is that parts of the skeletons of the people buried are missing.

Skulls and large bones are missing and may have been removed from the grave.

Now that the researchers have examined the material from the grave, they have found that it contains bones from hands and feet, fragments of rib bones and teeth.

But skulls and larger bones such as thigh and arm bones are very few.

"This differs from what we usually see in megalith graves, i.e. stone burial chambers from the Neolithic period," Karl-Göran Sjögren explains.

"Usually, the bones that are missing are smaller bones from feet and hands."

Torbjörn Ahlström, Professor of Osteology at Lund University, studied the bone finds.

His conclusion is that the bones come from at least twelve people, including infants and the elderly.

But the archaeologists don't yet know why they died.

"We haven't seen any injuries on the people buried so we don't think violence is involved. But we are continuing to study their DNA and that will show whether they had any diseases," says Karl-Göran Sjögren.

Falköping has long been known for its many passage graves dating from a somewhat later period, approximately 3300 BCE.

Agriculture reached Falbygden in about 4000 BCE, i.e. about 500 years before the grave in Tiarp was built.

In all likelihood, the people buried in the dolmen were farmers.

"They lived by growing grain and keeping animals and they consumed dairy products," says Karl-Göran Sjögren.

Are the people buried in the grave related?

A number of samples were taken at the excavation last summer, including DNA from the skeletal remains.

"The preliminary DNA results show that the DNA in the bones is well preserved. This means we will be able to reconstruct the family relationships between the people in the grave and we are working on that now," says Karl-Göran Sjögren.

Falbygden is known for its many traces of people from the Stone Age.

There are more than 250 passage graves here, large graves built of blocks of stone.

"But this dolmen is older. It's about 200 to 150 years older than the passage graves, making it one of the oldest stone burial chambers in Sweden and across the whole of Scandinavia," says Karl-Göran Sjögren.

There is another thing that makes the grave unique.

"It's the way it is constructed. There's a little niche at each end. This is unique for graves in Falbygden," says Karl-Göran Sjögren.

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Ancient asteroid grains provide insight into the evolution of our solar system

The UK's national synchrotron facility, Diamond Light Source, was used by a large, international collaboration to study grains collected from a near-Earth asteroid to further our understanding of the evolution of our solar system.

Researchers from the University of Leicester brought a fragment of the Ryugu asteroid to Diamond's Nanoprobe beamline I14 where a special technique called X-ray Absorption Near Edge Spectroscopy (XANES) was used to map out the chemical states of the elements within the asteroid material, to examine its composition in fine detail. The team also studied the asteroid grains using an electron microscope at Diamond's electron Physical Science Imaging Centre (ePSIC).

Julia Parker is the Principal Beamline Scientist for I14 at Diamond. She said: "The X-ray Nanoprobe allows scientists to examine the chemical structure of their samples at micron to nano lengthscales, which is complemented by the nano to atomic resolution of the imaging at ePSIC. It's very exciting to be able to contribute to the understanding of these unique samples, and to work with the team at Leicester to demonstrate how the techniques at the beamline, and correlatively at ePSIC, can benefit future sample return missions."

The data collected at Diamond contributed to a wider study of the space weathering signatures on the asteroid. The pristine asteroid samples enabled the collaborators to explore how space weathering can alter the physical and chemical composition of the surface of carbonaceous asteroids like Ryugu.

The researchers discovered that the surface of Ryugu is dehydrated and that it is likely that space weathering is responsible. The findings of the study, published today in Nature Astronomy, have led the authors to conclude that asteroids that appear dry on the surface may be water-rich, potentially requiring revision of our understanding of the abundances of asteroid types and the formation history of the asteroid belt.

Ryugu is a near-Earth asteroid, around 900 metres in diameter, first discovered in 1999 within the asteroid belt between Mars and Jupiter. It is named after the undersea palace of the Dragon God in Japanese mythology. In 2014, the Japanese state space agency JAXA launched Hayabusa2, an asteroid sample-return mission, to rendezvous with the Ryugu asteroid and collect material samples from its surface and sub-surface. The spacecraft returned to Earth in 2020, releasing a capsule containing precious fragments of the asteroid. These small samples were distributed to labs around the world for scientific study, including the University of Leicester's School of Physics & Astronomy and Space Park where John Bridges, one of the authors on the paper, is a Professor of Planetary Science.

John said: "This unique mission to gather samples from the most primitive, carbonaceous, building blocks of the Solar System needs the world's most detailed microscopy, and thats why JAXA and the Fine Grained Mineralogy team wanted us to analyse samples at Diamond's X-ray nanoprobe beamline. We helped reveal the nature of space weathering on this asteroid with micrometeorite impacts and the solar wind creating dehydrated serpentine minerals, and an associated reduction from oxidised Fe3+ to more reduced Fe2+.

It's important to build up experience in studying samples returned from asteroids, as in the Hayabusa2 mission, because soon there will be new samples from other asteroid types, the Moon and within the next 10 years Mars, returned to Earth. The UK community will be able to perform some of the critical analyses due to our facilities at Diamond and the electron microscopes at ePSIC."

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Thirsty wheat needed new water management strategy in ancient China

Research from Washington University in St. Louis shows that a practice of purposeful water management, or irrigation, was adopted in northern China about 4,000 years ago as part of an effort to grow new grains that had been introduced from southwest Asia.

But the story gets more complex from there. Wheat and barley arrived on the scene at about the same time, but early farmers only used water management techniques for wheat. The results, reported Nov. 9 in the journal Antiquity, raise awareness that the dispersal of domesticated crops and the knowledge of best using them can be traced independently across time and space.

"Pioneering farmers who cultivated wheat in this region managed water to meet the higher demand of this newly introduced grain," said Xinyi Liu, an associate professor of archaeology in Arts & Sciences, who collaborated on this study with researchers from several prominent institutions in China and Australia, including Guanghui Dong from Lanzhou University, who led the field expedition on the Loess Plateau. "The water management may have been achieved either by deliberate watering or by strategic planting in soils with higher water retention."

On the other hand, early farmers were able to grow the other new grain, barley, in a rainfed system as if it were just another kind of millet -- the locally domesticated and most commonly grown grain in northern China at the time -- without using any form of irrigation.

Liu published the study with Washington University graduate student Yufeng Sun. Other co-authors include Haiming Li and Petra Vaiglova, former members of Liu's lab group.

Introducing irrigation

Both wheat and barley were domesticated in an area known to archaeologists as the hilly flanks of the Fertile Crescent in southwest Asia, where they originally were grown as winter crops. Traditionally, farmers there sowed their seeds in autumn -- to avoid the summer drought period -- and harvested them in late spring or early summer before the next drought season.

When these Fertile Crescent crops, wheat and barley, were introduced to East Asia about 4,000 years ago, they would have encountered a markedly different climate compared with where they originated.

"Every summer, the East Asian monsoon brings rains from the Pacific Ocean to a region otherwise arid throughout the rest of the year. This environment is perfect for rainfed millet cultivation as these local grains are drought tolerant but need considerable water in the summer growing season," Liu said. "But it is a different story if you try to grow wheat there, not only because it is water demanding, but also the growing cycle doesn't match the rainy season."

Liu and his colleagues wanted to know: Did the farmers who sought to grow the new grains in northern China also introduce new systems of irrigation to support them?

"The introduction of a new irrigation system is something that scholars have speculated about, but now we have the technology to seek direct evidence," Liu said.

Using relatively new techniques, the actual growing conditions of past crops -- including past water and soil conditions during plant growth -- can be measured using the stable carbon and nitrogen isotope compositions of charred plant remains. These methods initially were established in plant science for research concerning environmental conditions of modern-day agriculture and have been subsequently applied to archaeological research.

Previous studies using similar approaches have shed significant light on early crop management in Europe and the Middle East. This research is one of the first attempts to apply it to East Asian monsoon environments with innovative questions.

For this study, the scientists identified more than 35,000 charred seed remains of cereal plants, including wheat, barley and millet, from more than 50 archaeological sites excavated on the Loess Plateau of China spanning a timeframe over eight millennia. Selected plant remains from this collection were radiocarbon dated and isotopically measured.

The results showed major differences between wheat and barley.

Despite the arid local environment, the majority of the wheat samples from all time periods had isotopic values above an optimal watering threshold, indicating that their growth was not limited by water availability.

"We see this in the Qijia culture period, when wheat and barley were just introduced to this region," Liu said. "The isotopic data of wheat show a significant level of water manipulation unambiguously since 4,000 years ago, indicating the new crop was introduced with water management strategies to support it."

Simple ditches can be powerful

This evidence alone does not necessarily imply large-scale irrigation, Liu is quick to point out; instead, wheat crops may have been strategically sown in areas with the best water availability, either close to local springs or in soils with high water retention.

"In those locations, small ditches to diffuse water is sufficient," Liu said. "This explains why there is no archaeological evidence of channels or other irrigation installations in the area until much later."

Barley, on the other hand, appears to have been grown on the dry hills of the Loess Plateau without a special water management approach -- a landscape and cultivation strategy that had been familiar to the Neolithic millet farmers since 8,000 years ago.

This and other evidence suggest to Liu and his collaborators that ancient farmers sought to optimize land use and crop yield by taking advantage of the different water demands of these two crops.

"Our results raise an awareness that the dispersal of domesticated crops and the knowledge of best using them can be traced independently across time and space," Liu said.

"Central to our inquiry is the tension between non-native crops and indigenous farming practices," he said. "When non-native innovations were adopted in another cultural and physical environment, they would have been transformed within the local context. How this happens is an enduring question that is relevant to globalization in the past and present."

This study resonates with other archaeological investigations led by Liu's research group, the Laboratory for the Analysis of Early Food-Webs at Washington University. For example, co-author Sun's previous work with Washington University graduate student Melissa Ritchey demonstrated a similar geographic decoupling of the dispersal of grains and cuisines, such that wheat and barley dispersed into ancient China 4,000 years ago, but the western grinding-and-baking cuisines did not. The eastern movement of these grains involved selections of phenotypic traits adapted to ancient China's cooking tradition of using steaming-and-boiling.

It has been a long time since some scholars assumed the association between the origin of bureaucracy and irrigation, and ancient China had been used as an example of "oriental despotism," according to Liu. The "hydraulic empire" hypothesis speculated that a centralized government structure that maintained power would have been derived from the need for flood control and irrigation.

Read more at Science Daily

Bronze Age farmers gave preferential treatment to cows over domesticated sheep, goats

The movements of ancient crop and animal domesticates across prehistoric Eurasia are well-documented in the archaeological record. What is less well understood: How Bronze Age farmers and herders incorporated newly introduced domesticates -- like cows from southwestern Asia -- into their long-standing animal husbandry and culinary traditions.

New research led by archaeologists at Washington University in St. Louis shows that meat and dairy played a more significant role in human diets in Bronze Age China than previously thought. The analysis also suggests that farmers and herders tended to sheep and goats differently than they did their cows, unlike in other parts of the world -- keeping cows closer to home and feeding them the byproducts of grains that they were growing for their own consumption, like the grass stalks from millet plants.

The study published in Scientific Reports integrates new and previously published data from nine sites along the Hexi Corridor, a key region between the Gobi Desert and Tibetan Plateau that facilitated the movement of ancient crops between Central and East Asia.

Petra Vaiglova, postdoctoral research associate, and Xinyi Liu, associate professor of archaeology in Arts & Sciences, based their analysis on bone records and other isotopic data from humans, animals and plants.

"Using the method of stable isotope analysis, we looked at the diets of the local herbivores that were managed in the Bronze Age Hexi Corridor of northwestern China," Vaiglova said. "The results showed that cattle and sheep or goats were managed distinctly in the different ecological niches across the study region. We propose that this was a result of varying management choices made by the local farmers, who aimed to strike a balance between tradition and innovation.

"In previous research, this method has been applied to understanding the nature of human diets, and the role of different domesticates in it," she said. "In this paper, we switched focus to trying to understand the minutiae of animal diets -- and what that tells us about animal management in the Bronze Age."

While sheep and goats seem to have eaten naturally available vegetation by grazing in the vicinity of the villages, the scientists found evidence that cattle were both grazed and fed. The cattle bones that the researchers analyzed exhibited a higher input of plants that are more adapted to arid conditions in places where these plants contributed little to the natural vegetation. This group of crops includes millet, which was originally cultivated in Eastern Asia.

These findings suggest that cattle diets were more influenced by human provisioning and that cattle may therefore have been reared closer to the human settlements than sheep and goats.

Liu and other researchers in his laboratory at Washington University study how social and culinary systems react to novel crops and exotic domestic animals in China. His research has revealed how foreign innovations adopted in ancient Central China were transformed within existing and highly organized social and cultural systems.

"Our results suggest a similar process in the adoption and localization of cattle in the Hexi Corridor, an animal domesticated in a markedly different environment," Liu said. "In locations with limited grazing lands suitable for pasturing of cattle, people adapted the local pig-rearing economy towards cattle stall-feeding."

These conclusions resonate with modern ethnographic examples from North China, the researchers said, where cattle are more tethered to human settlements, rather than being allowed to roam on local or more distant pastures alongside sheep and goats.

Understanding past farming and dietary conditions can help us with some of the challenges we face in today's world, Liu said. Those challenges are as much environmental as social.

"In the context of a warming climate, where soil moisture is predicted to be increasingly depleted on a global scale, one can draw parallels to the Mid-Holocene conditions of northwest China," Liu said.

Read more at Science Daily

5200-year-old grains in the eastern Altai Mountains redate trans-Eurasian crop exchange

Most people are familiar with the historical Silk Road, but fewer people realize that the exchange of items, ideas, technology, and human genes through the mountain valleys of Central Asia started almost three millennia before organized trade networks formed. These pre-Silk Road exchange routes played an important role in shaping human cultural developments across Europe and Asia, and facilitated the dispersal of technologies such as horse breeding and metal smelting into East Asia. One of the most impactful effects of this process of ancient cultural dispersal was the westward spread of northeast Asian crops and the eastward spread of southwest Asian crops. However, until the past few years, a lack of archaeobotanical studies in Central Asia left a dearth of data relating to when and how this process occurred.

This new study, led by scientists from the Chinese Academy of Sciences and the Max Planck Institute for the Science of Human History, provides details of recently recovered ancient grains from the far northern regions of Inner Asia. Radiocarbon dating shows that the grains include the oldest examples of wheat and barley ever recovered this far north in Asia, pushing back the dates for early farming in the region by at least a millenium. These are also the earliest domesticated plants reported from the northern half of Central Asia, the core of the ancient exchange corridor. This study pulls together sedimentary pollen and ancient wood charcoal data with archaeobotanical remains from the Tiangtian archaeological site in the Chinese Altai Mountains to reveal how humans cultivated crops at such northern latitudes. This study illustrates how adaptable ancient crop plants were to new ecological constraints and how human cultural practices allowed people to survive in unpredictable environments.

The Northern Dispersal of Cereal Grains

The ancient relatives of wheat and barley plants evolved to grow in the warm and dry climate of the eastern Mediterranean and southwest Asia. However, this study illustrates that ancient peoples were cultivating these grasses over five and a half thousand kilometers to the northeast of where they originally evolved to grow. In this study, Dr. Xinying Zhou and his colleagues integrate paleoenvironmental proxies to determine how extreme the ecology was around the archaeological cave site of Tangtian more than five millennia ago, at the time of its occupation. The site is located high in the Altai Mountains on a cold,dry landscape today; however, the study shows that the ecological setting around the site was slightly warmer and more humid at the time when people lived in and around this cave.

The slightly warmer regional conditions were likely the result of shifting air masses bringing warmer, wetter air from the south. In addition to early farmers using a specific regional climate pocket to grow crops in North Asia, analysis showed that the crops they grew evolved to survive in such northern regions. The results of this study provide scholars with evidence for when certain evolutionary changes in these grasses occurred, including changes in the programed reliance of day length, which signals to the plant when to flower, and a greater resistance to cold climates.

The Trans-Eurasian Exchange and Crop Dispersal

The ancient dispersal of crops across Inner Asia has received a lot of attention from biologists and archaeologists in recent years; as Dr. Spengler, one of the study's lead authors, discusses in his recent book Fruit from the Sands, these ancient exchange routes shaped the course of human history. The mingling of crops originating from opposite ends of Asia resulted in the crop-rotation cycles that fueled demographic growth and led to imperial formation. East Asian millets would become one of the most important crops in ancient Europe and wheat would become one of the most important crops in East Asia by the Han Dynasty. While the long tradition of rice cultivation in East Asia made rice a staple of the Asian kitchen, Chinese cuisine would be unrecognizable without wheat-based food items like steamed buns, dumplings, and noodles. The discovery that these plants dispersed across Eurasia earlier than previously understood will have lasting impacts on the study of cultivation and labor practices in ancient Eurasia, as well as the history cultural contact and shifts in culinary systems throughout time.

These new discoveries provide reason to question these views, and seem to suggest that mixed small-scale human populations made major contributions to world history through migration and cultural and technological exchange. "This study not only presents the earliest dates for domesticated grains in far North Asia," says Professor Xiaoqiang Li, director of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, "it represents the earliest beginning of a trans-Eurasian exchange that would eventually develop into the great Silk Road."

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Meteorite chunk contains unexpected evidence of presolar grains

Illustration of meteor falling to Earth.

An unusual chunk in a meteorite may contain a surprising bit of space history, based on new research from Washington University in St. Louis.

Presolar grains -- tiny bits of solid interstellar material formed before the sun was born -- are sometimes found in primitive meteorites. But a new analysis reveals evidence of presolar grains in part of a meteorite where they are not expected to be found.

"What is surprising is the fact that presolar grains are present," said Olga Pravdivtseva, research associate professor of physics in Arts & Sciences and lead author of a new paper in Nature Astronomy. "Following our current understanding of solar system formation, presolar grains could not survive in the environment where these inclusions are formed."

Curious Marie is a notable example of an "inclusion," or a chunk within a meteorite, called a calcium-aluminum-rich inclusion (CAI). These objects, some of the first to have condensed in the solar nebula, help cosmochemists define the age of the solar system. This particular chunk of meteorite -- from the collection of the Robert A. Pritzker Center for Meteoritics and Polar Studies at the Chicago Field Museum -- was in the news once before, when scientists from the University of Chicago gave it its name to honor chemist Marie Curie.

For the new work, Pravdivtseva and her co-authors, including Sachiko Amari, research professor of physics at Washington University, used noble gas isotopic signatures to show that presolar silicon carbide (SiC) grains are present in Curious Marie.

That's important because presolar grains are generally thought to be too fragile to have endured the high-temperature conditions that existed near the birth of our sun.

But not all CAIs were formed in quite the same way.

"The fact that SiC is present in refractory inclusions tells us about the environment in the solar nebula at the condensation of the first solid materials," said Pravdivtseva, who is part of Washington University's McDonnell Center for the Space Sciences. "The fact that SiC was not completely destroyed in Curious Marie can help us to understand this environment a little bit better.

"Many refractory inclusions were melted and lost all textural evidence of their condensation. But not all."

Like solving a mystery

Pravdivtseva and her collaborators used two mass spectrometers built in-house at Washington University to make their observations. The university has a long history of noble gas work and is home to one of the best-equipped noble gas laboratories in the world. Still, this work was uniquely challenging.

The researchers had 20 mg of Curious Marie to work with, which is a relatively large sample from a cosmochemistry perspective. They heated it up incrementally, increasing temperature and measuring the composition of four different noble gases released at each of 17 temperature steps.

"Experimentally, it is an elegant work," Pravdivtseva said. "And then we had a puzzle of noble gas isotopic signatures to untangle. For me, it is like solving a mystery."

Others have looked for evidence of SiC in such calcium-aluminum-rich inclusions in meteorites using noble gases before, but Pravdivtseva's team is the first to find it.

"It was beautiful when all noble gases pointed to the same source of the anomalies -- SiC," she said.

Read more at Science Daily