Bronze Age Scandinavia's trading networks for copper settled

Bronze Age Scandinavia's trading networks for copper settled

Crossing the North Sea before crossing the Alps!

trading bronze age Scandinavia's
Shafthole axe type Fårdrup. This axe is of Nordic craftsmanship and hides information on the first attempt to establish trading networks with societies across the Alps. A small group of these Nordic crafted axes is made of northern Italian copper, so called AATV-copper (from the Alto Adige, Trentino and Veneto mining region in the Italian Alps) while the majority of these axes is made of British and Welsh or eastern Alpine metal. Photo credits: Heide W. Nørgaard, by permission of the National Museum, Copenhagen

New research presents over 300 new analyses of bronze objects, raising the total number to 550 in 'the archaeological fingerprint project'. This is roughly two thirds of the entire metal inventory of the early Bronze Age in southern Scandinavia. For the first time, it was possible to map the trade networks for metals and to identify changes in the supply routes, coinciding with other socio-economic changes detectable in the rich metal-dependent societies of Bronze Age southern Scandinavia.

The magnificent Bronze Age in southern Scandinavia rose from copper traded from the British Isles and Slovakia 4000 years ago. 500 years later these established trade networks collapsed and fresh copper was then traded from the southern Alps, the so-called Italian Alps. This large-scale study could show that during the first 700 years of the Nordic Bronze Age the metal supplying networks and trade routes changed several times. These 700 years of establishment and change led to a highly specialised metalwork culture boasting beautiful artwork such as the Trundholm Sun wagon and spiral decorated belt plates branding high-ranking women; even depicted on today's Danish banknotes.

The lead isotope plot of the over 65 shafthole axes analyzed in this study dating to the end of the first Bronze Age period 1600 BC. This amount of data exceeds the previous analyses by ten times and for the first time allows to compare both axe types and understand their development

The study by H. Nørgaard, Moesgaard Museum and her colleagues H. Vandkilde from Aarhus University and E. Pernicka from the Curt-Engelhorn Centre in Mannheim built on the so far largest dataset of chemical and isotope data of ancient bronze artefacts. In total 550 objects were used to model the changes that took place: These changes correlate with major shifts in social organisation, settlements, housing, burial rites and long distance mobility.

trading bronze age Scandinavia's
Shafthole axe of Valsømagle type. Only a few axes of this type are known, and they are only distributed in northern Europe. These axes seem to be contemporary with the Fårdrup type axes as they are made of the same metal and not, if they would be slightly later, of the new Italian metal that is the main metal used in the period from 1500 BC. Photo credits: Heide W. Nørgaard, by permission of the National Museum, Copenhagen

"Now, this multi-disciplinary approach - based jointly on conventional archaeological methods and novel scientific methodologies processing large data quantities - allows us to detect these correlating changes and identify contemporaneity with societal changes recognised by colleague researchers", says Heide Nørgaard the project´s PI.

"It is highly likely that both people and technologies arrived to Scandinavia and that Scandinavians travelled abroad to acquire copper by means of the Nordic amber, highly valued by European trading partners".

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Citation: Nørgaard HW, Pernicka E, Vandkilde H (2021) Shifting networks and mixing metals: changing metal trade routes to Scandinavia correlate with Neolithic and Bronze Age transformations. PLOS ONEhttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0252376

 

Bronze Age Scandinavia's trading networks for copper settled: press release from Aarhus University.


5,200-year-old grains in the eastern Altai Mountains redate trans-Eurasian crop exchange

5,200-year-old grains in the eastern Altai Mountains redate trans-Eurasian crop exchange

Agricultural crops dispersed across Eurasia more than five millennia ago, causing significant cultural change in human populations across the ancient world. New discoveries in the Altai Mountains illustrate that this process occurred earlier than believed

trans-Eurasian crop exchange
Dr. Xinying Zhou and his team from the IVPP in Beijing excavated the Tangtian Cave site during the summer of 2016. Credits: Xinying Zhou

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.

trans-Eurasian crop exchange
Charred seeds from Tontian Cave site. Credits: Xinying Zhou

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".

Dr. Xinying Zhou, who headed the study and directs a research team at the IVPP in Beijing, emphasizes that "this discovery is a testament to human ingenuity and the amazing coevolutionary bond between people and the plants that they maintain in their cultivated fields."

photo of the stone men (????? Chimulchek Culture) in the steppe area of Altai Mountains. These figures are characteristic of the peoples who live in the area around the time of occupation at Tongtian. These specific examples are located at the Chimulchek site (ca. 4000 years old) and not far from Tongtian Cave. Ceramic sherds from the cave suggest that the occupants in the cave shared similar cultural traits to other people in the region. Credits: Jianjun Yu

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Title: 5200-year-old cereal grains from the eastern Altai Mountains predate the trans-Eurasian crop exchange
Authors: Xinying Zhou, Jianjun Yu, Robert Nicolas Spengler, Hui Shen, Keliang Zhao, Junyi Ge, Yige Bao, Junchi Liu, Qingjiang Yang, Guanhan Chen, Peter Weiming Jia, and Xiaoqiang Li
Publication: Nature Plants
DOI: https://doi.org/10.1038/s41477-019-0581-y

 

The press release about the trans-Eurasian crop exchange is from Max Planck Institute for the Science of Human History / DE


Citi exhibition Arctic: culture and climate

"Arctic: culture and climate", an exhibition on the history of the Arctic people

British Museum announces major exhibition on the Arctic
The Citi exhibition Arctic: culture and climate

28 May – 23 August 2020
Sainsbury Exhibitions Gallery

Lead supporter Citi
Supported by
Julie and Stephen Fitzgerald
AKO Foundation

There's Another One

In May 2020 the British Museum will open the first major exhibition on the history of the Arctic and its indigenous peoples, through the lens of climate change and weather. The Arctic has been home to resilient communities for nearly 30,000 years, cultures that have lived with the opportunities and challenges of one of the most dramatic and dynamic environments on the planet. Today climate change is transforming the Arctic at the fastest rate in human history. The Citi exhibition Arctic: culture and climate is the first to look at the circumpolar region through the eyes of contemporary Arctic communities, revealing how Arctic peoples have adapted to climate variability in the past and addresses the global issue of changing climate through their stories in a transforming world.

Citi exhibition Arctic: culture and climate
Arctic Foliage wall hanging

Bringing together the largest and most diverse circumpolar collection ever displayed in the UK, including objects from the British Museum’s world-class Arctic collection and international lenders and commissions, this exhibition will reveal a wealth of artistic expression and ecological knowledge, from the past right up to the present day. From rare 28,000 year old archaeological finds excavated from the thawing ground in Siberia, unique tools and clothing adapted for survival, artworks reflecting the respectful relationship between Arctic people and the natural world, to stunning photography of contemporary daily life, the exhibition will show the great diversity of cultures and ingenuity of communities responding to dramatic changes in seasonal weather and human-caused climate change.

Walrus ivory needles, Yana-site, Russia

The Arctic Circle is the most northern region in the world encompassing the area of midnight sun in summer and the polar night in winter that covers 4% of the Earth. It is home to 4 million people including 400,000 indigenous peoples belonging to one or more of 40 different ethnic groups with distinct languages and dialects. Most of the Arctic’s indigenous inhabitants rely on hunting, fishing and reindeer herding. These subsistence resources are supplemented by employment in industries such as government infrastructures, energy, commercial fishing and tourism.

Arctic peoples have traded and engaged across the Circumpolar North for millennia. From Russia, Greenland, Canada and the USA to the Scandinavian nations, the peoples of the region have thrived within this ever-changing and evolving landscape. Scientists predict that the Arctic will be ice-free in 80 years, which will bring dramatic and profound change to the people that live there and will affect us all.

Citi exhibition Arctic: culture and climate
Sledge

Twyla Thurmond, tribal coordinator, from Shishmaref, Alaska says “Shishmaref and other Alaska Native communities are demonstrating how people can stay strong and unified in their search for answers to climate change, the most challenging problem of the 21st century.”

The exhibition will feature many highlight objects from across the circumpolar region, including an 8-piece Igloolik winter costume made of caribou (wild reindeer) fur, illustrating the relationship between humans and animals in the Arctic. The hunted animal provides food for the community as well as clothing, perfectly adapted to help humans survive the extreme cold. All available natural materials are put to use. A delicate and unique household bag from western Alaska, crafted from tanned salmon skin, demonstrates the beautiful properties that emerge from fishskin when skilled practitioners work and expose material to particular weather conditions.

Icon into mask

Over the past 300 years, Arctic peoples have faced dramatic social, economic, and political changes as a result of European and Russian exploration to the region, quests for the Northwest Passage, and the global fur trade. A key object from this period is the Inughuit (Greenlandic) sled made from narwhal and caribou bone and pieces of driftwood. It was traded to Sir John Ross on his 1818 expedition, marking the first encounter between Inughuit and Europeans. Arctic peoples’ responses to the establishment of colonial governments and state-sponsored religions in the Arctic will feature, including a bronze carved Evenki spirit mask that was made from a 17th century Russian Orthodox icon. Today, Arctic peoples are transforming traditional heritage to meet contemporary needs and safeguard their culture. From performances adapted from ritual practices to commercial artwork inspired by storytelling and material traditions.

Citi exhibition Arctic: culture and climate
Inukshuk

Stunning contemporary photography of the Arctic landscape and local communities will form part of the immersive exhibition design. There will be a number of new artworks commissioned for the exhibition. These include a limestone Inuksuk, an iconic Arctic monument of stacked stones used to mark productive harvesting locations or to assist in navigation, built by Piita Irniq, from the Kivalliq Region of Nunavut, Canada. A new installation from the art collective Embassy of Imagination will present traditional clothing made from Japanese paper and printmaking by Inuit youth in Kinngait (Cape Dorset) and Puvirnitug, Nunavut, Canada.

Citi exhibition Arctic: culture and climate
Sami hat

The Citi exhibition Arctic: culture and climate will tell inspirational stories of human achievement while celebrating the region’s natural beauty. It will encourage debate about the future of this globally significant landscape in the light of the global climate change. Arctic peoples have faced different kinds of change, developing strategies and tools to mitigate the disruptive effects of social and environmental change from which we can all learn.

Lead supporter Citi

Supported by Julie and Stephen Fitzgerald, and AKO Foundation

Amber Lincoln, Curator, Americas Section, British Museum, said ‘Through the generosity of indigenous Arctic people and Arctic scholars, this exhibition weaves together compelling stories, objects and landscapes of the Circumpolar North, at a time when the Arctic is changing before our very eyes.’

Hartwig FischerDirector of the British Museum, said ‘The Citi exhibition Arctic: culture and climate is a bold and ambitious exhibition that reflects the expanding vision of the British Museum. The show directly addresses the essential question of how humans can live with the impacts of extreme weather. The future and past come together in the present, united by the shared experiences of Arctic peoples. I would like to thank Citi, whose on-going support has allowed the Museum to realise this ground-breaking exhibition.’

James Bardrick, Citi Country Officer, United Kingdom says: “As a global bank, we play an essential role in financing a sustainable economy and supporting indigenous peoples’ rights. We are particularly proud to partner with the British Museum for the forthcoming Arctic: culture and climate exhibition that sheds light on the formidable artistic expression and ecological knowledge of the Arctic populations. We are committed to financing and facilitating clean energy, infrastructure and technology projects that support environmental solutions and reduce the impacts of climate change, on rich and diverse communities such as those that inhabit the circumpolar Arctic.”

Citi exhibition Arctic: culture and climate
Umiaq and north wind during spring whaling by Kiliii Yuyan

If you want to read more about Arctic: culture and climate, follow the British Museum blog at blog.britishmuseum.org

 

Press release from the British Museum

Pictures courtesy of the British Museum


Archaeologists find Bronze Age tombs lined with gold near the Griffin Warrior

Archaeologists find Bronze Age tombs lined with gold

The family tombs are near the 2015 site of the 'Griffin Warrior,' a military leader buried with armor, weapons and jewelry.

A gold ring depicts bulls and barley, the first known representation of domesticated animals and agriculture in ancient Greece. Credits: UC Classics

Archaeologists with the University of Cincinnati have discovered two Bronze Age tombs containing a trove of engraved jewelry and artifacts that promise to unlock secrets about life in ancient Greece.

The UC archaeologists announced the discovery Tuesday in Greece.

Jack Davis and Sharon Stocker, archaeologists in UC's classics department, found the two beehive-shaped tombs in Pylos, Greece, last year while investigating the area around the grave of an individual they have called the "Griffin Warrior," a Greek man whose final resting place they discovered nearby in 2015.

Like the Griffin Warrior's tomb, the princely tombs overlooking the Mediterranean Sea also contained a wealth of cultural artifacts and delicate jewelry that could help historians fill in gaps in our knowledge of early Greek civilization.

UC's team spent more than 18 months excavating and documenting the find. The tombs were littered with flakes of gold leaf that once papered the walls.

"Like with the Griffin Warrior grave, by the end of the first week we knew we had something that was really important," said Stocker, who supervised the excavation.

"It soon became clear to us that lightning had struck again," said Davis, head of UC's classics department.

Bronze Age Tombs Griffin Warrior Pylos
UC archaeologists discovered two large family tombs at Pylos, Greece, strewn with flakes of gold that once lined their walls. The excavation took more than 18 months. Credits: UC Classics

The Griffin Warrior is named for the mythological creature -- part eagle, part lion -- engraved on an ivory plaque in his tomb, which also contained armor, weaponry and gold jewelry. Among the priceless objects of art was an agate sealstone depicting mortal combat with such fine detail that Archaeology magazine hailed it as a "Bronze Age masterpiece."

Artifacts found in the princely tombs tell similar stories about life along the Mediterranean 3,500 years ago, Davis said. A gold ring depicted two bulls flanked by sheaves of grain, identified as barley by a paleobotanist who consulted on the project.

"It's an interesting scene of animal husbandry -- cattle mixed with grain production. It's the foundation of agriculture," Davis said. "As far as we know, it's the only representation of grain in the art of Crete or Minoan civilization."

UC archaeologists found a sealstone made from semiprecious carnelian in the family tombs at Pylos, Greece. The sealstone was engraved with two lionlike mythological figures called genii carrying serving vessels and incense burners facing each other over an altar and below a 16-pointed star. The other image is a putty cast of the sealstone. Credits: UC Classics

Like the grave of the Griffin Warrior, the two family tombs contained artwork emblazoned with mythological creatures. An agate sealstone featured two lion-like creatures called genii standing upright on clawed feet. They carry a serving vase and an incense burner, a tribute for the altar before them featuring a sprouting sapling between horns of consecration, Stocker said.

Above the genii is a 16-pointed star. The same 16-pointed star also appears on a bronze and gold artifact in the grave, she said.

"It's rare. There aren't many 16-pointed stars in Mycenaean iconography. The fact that we have two objects with 16 points in two different media (agate and gold) is noteworthy," Stocker said.

The genius motif appears elsewhere in the East during this period, she said.

"One problem is we don't have any writing from the Minoan or Mycenaean time that talks of their religion or explains the importance of their symbols," Stocker said.

UC's team also found a gold pendant featuring the likeness of the Egyptian goddess Hathor.

"Its discovery is particularly interesting in light of the role she played in Egypt as protectress of the dead," Davis said.

The identity of the Griffin Warrior is a matter for speculation. Stocker said the combination of armor, weapons and jewelry found in his tomb strongly indicate he had military and religious authority, likely as the king known in later Mycenaean times as a wanax.

Likewise, the princely tombs paint a picture of accumulated wealth and status, she said. They contained amber from the Baltic, amethyst from Egypt, imported carnelian and lots of gold. The tombs sit on a scenic vista overlooking the Mediterranean Sea on the spot where the Palace of Nestor would later rise and fall to ruins.

"I think these are probably people who were very sophisticated for their time," she said. "They have come out of a place in history where there were few luxury items and imported goods. And all of a sudden at the time of the first tholos tombs, luxury items appear in Greece.

"You have this explosion of wealth. People are vying for power," she said. "It's the formative years that will give rise to the Classic Age of Greece."

The antiquities provide evidence that coastal Pylos was once an important destination for commerce and trade.

"If you look at a map, Pylos is a remote area now. You have to cross mountains to get here. Until recently, it hasn't even been on the tourist path," Stocker said. "But if you're coming by sea, the location makes more sense. It's on the way to Italy. What we're learning is that it's a much more central and important place on the Bronze Age trade route."

The princely tombs sit close to the palace of Nestor, a ruler mentioned in Homer's famous works "The Iliad" and "The Odyssey." The palace was discovered in 1939 by the late UC Classics professor Carl Blegen. Blegen had wanted to excavate in the 1950s in the field where Davis and Stocker found the new tombs but could not get permission from the property owner to expand his investigation. The tombs would have to wait years for another UC team to make the startling discovery hidden beneath its grape vines.

Excavating the site was particularly arduous. With the excavation season looming, delays in procuring the site forced researchers to postpone plans to study the site first with ground-penetrating radar. Instead, Stocker and Davis relied on their experience and intuition to focus on one disturbed area.

"There were noticeable concentrations of rocks on the surface once we got rid of the vegetation," she said.

Those turned out to be the exposed covers of deep tombs, one plunging nearly 15 feet. The tombs were protected from the elements and potential thieves by an estimated 40,000 stones the size of watermelons.

The boulders had sat undisturbed for millennia where they had fallen when the domes of the tombs collapsed. And now 3,500 years later, UC's team had to remove each stone individually.

"It was like going back to the Mycenaean Period. They had placed them by hand in the walls of the tombs and we were taking them out by hand," Stocker said. "It was a lot of work."

At every step of the excavation, the researchers used photogrammetry and digital mapping to document the location and orientation of objects in the tomb. This is especially valuable because of the great number of artifacts that were recovered, Davis said.

"We can see all levels as we excavated them and relate them one to the other in three dimensions," he said. UC's team will continue working at Pylos for at least the next two years while they and other researchers around the world unravel mysteries contained in the artifacts.

"It has been 50 years since any substantial tombs of this sort have been found at any Bronze Age palatial site. That makes this extraordinary," Davis said.

 

Press release from the University of Cincinnati, by Michael Miller.


timber Roman timber trade trading

Long-distance timber trade underpinned the Roman Empire's construction

Long-distance timber trade underpinned the Roman Empire's construction

timber Roman timber trade trading
Some of the oak planks in situ in the foundation of the portico. Credit: Bernabei at al., 2019, CC-BY

The ancient Romans relied on long-distance timber trading to construct their empire, according to a study published December 4, 2019 in the open-access journal PLOS ONE by Mauro Bernabei from the National Research Council, Italy, and colleagues.

The timber requirements of ancient Rome were immense and complex, with different types of trees from various locations around the Roman Empire and beyond used for many purposes, including construction, shipbuilding and firewood. Unfortunately, the timber trade in ancient Rome is poorly understood, as little wood has been found in a state adequate for analysis. In this study, Bernabei et al successfully date and determine the origin and chronology of unusually well-preserved ancient Roman timber samples.

The twenty-four oak timber planks (Quercus species) analyzed in this study were excavated during Metro construction in Rome during 2014-2016. They formed part of a Roman portico in the gardens of via Sannio (belonging to what was once a lavishly decorated and rich property). The authors measured the tree-ring widths for each plank and ran statistical tests to determine average chronology, successfully dating thirteen of the planks.

By comparing their dated planks to Mediterranean and central European oak reference chronologies, the authors found that the oaks used for the Roman portico planks were taken from the Jura mountains in eastern France, over 1700km away. Based on the sapwood present in 8 of the thirteen samples, the authors were able to narrow the date these oaks were felled to between 40 and 60 CE and determined that the planks all came from neighboring trees. Given the timber's dimensions and the vast distance it travelled, the authors suggest that ancient Romans (or their traders) likely floated the timber down the Saône and Rhône rivers in present-day France before transporting it over the Mediterranean Sea and then up the river Tiber to Rome, though this cannot be confirmed.

The authors note that the difficulty of obtaining these planks--which were not specially sourced for an aesthetic function but used in the portico's foundations--suggests that the logistical organization of ancient Rome was considerable, and that their trade network was highly advanced.

Bernabei notes: "This study shows that in Roman times, wood from the near-natural woodlands of north-eastern France was used for construction purposes in the centre of Rome. Considering the distance, calculated to be over 1700km, the timber sizes, [and] the means of transportation with all the possible obstacles along the way, our research emphasises the importance of wood for the Romans and the powerful logistic organisation of the Roman society."

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Citation: Bernabei M, Bontadi J, Rea R, Büntgen U, Tegel W (2019) Dendrochronological evidence for long-distance timber trading in the Roman Empire. PLoS ONE 14(12): e0224077. https://doi.org/10.1371/journal.pone.0224077

Funding: WT received funding from the German Research Foundation (DFG, TE 613/3-2). UB received funding from the Czech Republic Grant Agency (17-22102s).

Competing Interests: The authors have declared that no competing interests exist.

 

Press release from the Public Library of Sciences.

 


apple

Exploring the origins of the apple

Exploring the origins of the apple

Apples originally evolved in the wild to entice ancient megafauna to disperse their seeds; more recently, humans began spreading the trees along the Silk Road with other familiar crops; dispersing the apple trees led to their domestication

wild horses apple
Horses eating wild apples in the Tien Shan Mountains. These domesticated horses demonstrate the process of seed dispersal that wild apple trees evolved to support millions of years ago, when large monogastric mammals such as these were prominent across Eurasia. Credit: Artur Stroscherer

Recent archaeological finds of ancient preserved apple seeds across Europe and West Asia combined with historical, paleontological, and recently published genetic data are presenting a fascinating new narrative for one of our most familiar fruits. In this study, Robert Spengler of the Max Planck Institute for the Science of Human History traces the history of the apple from its wild origins, noting that it was originally spread by ancient megafauna and later as a process of trade along the Silk Road. These processes allowed for the development of the varieties that we know today.

The apple is, arguably, the most familiar fruit in the world. It is grown in temperate environments around the globe and its history is deeply intertwined with humanity. Depictions of large red fruits in Classical art demonstrate that domesticated apples were present in southern Europe over two millennia ago, and ancient seeds from archaeological sites attest to the fact that people have been collecting wild apples across Europe and West Asia for more than ten thousand years. While it is clear that people have closely maintained wild apple populations for millennia, the process of domestication, or evolutionary change under human cultivation, in these trees is not clear.

Several recent genetic studies have demonstrated that the modern apple is a hybrid of at least four wild apple populations, and researchers have hypothesized that the Silk Road trade routes were responsible for bringing these fruits together and causing their hybridization. Archaeological remains of apples in the form of preserved seeds have been recovered from sites across Eurasia, and these discoveries support the idea that fruit and nut trees were among the commodities that moved on these early trade routes. Spengler recently summarized the archaeobotanical and historical evidence for cultivated crops on the Silk Road in a book titled Fruit from the Sands, published with the University of California Press. The apple holds a deep connection with the Silk Road - much of the genetic material for the modern apple originated at the heart of the ancient trade routes in the Tien Shan Mountains of Kazakhstan. Furthermore, the process of exchange caused the hybridization events that gave rise to the large red sweet fruits in our produce markets.

Understanding how and when apple trees evolved to produce larger fruits is an important question for researchers, because fruit trees do not appear to have followed the same path towards domestication as other, better-understood crops, such as cereals or legumes. Many different wild and anthropogenic forces apply selective pressure on the crops in our fields, it is not always easy to reconstruct what pressures caused which evolutionary changes. Therefore, looking at evolutionary processing in modern and fossil plants can help scholars interpret the process of domestication. Fleshy sweet fruits evolve to attract animals to eat then and spread their seeds; large fruits specifically evolve to attract large animals to disperse them.

apple
The wild apples in the Tien Shan Mountains represent the main ancestral population for our modern apple. These trees produce large fruits, which are often red when ripe and have a varying array of flavors. These were the ancestors of the trees that people first started to cultivate and spread along the Silk Road. Credit: Prof. Dr. Martin R. Stuchtey

Large fruits evolved to attract ancient megafauna

While most scholars studying domestication focus on the period when humans first start cultivating a plant, in this study Spengler explores the processes in the wild that set the stage for domestication. Spengler suggests that understanding the process of evolution of large fruits in the wild will help us understand the process of their domestication. "Seeing that fruits are evolutionary adaptations for seed dispersal, the key to understanding fruit evolution rests in understanding what animals were eating the fruits in the past," he explains.

Many fruiting plants in the apple family (Rosaceae) have small fruits, such as cherries, raspberries, and roses. These small fruits are easily swallowed by birds, which then disperse their seeds. However, certain trees in the family, such as apples, pears, quince, and peaches, evolved in the wild to be too large for a bird to disperse their seeds. Fossil and genetic evidence demonstrate that these large fruits evolved several million years before humans started cultivating them. So who did these large fruits evolve to attract?

The evidence suggests that large fruits are an evolutionary adaptation to attract large animals that can eat the fruits and spread the seeds. Certain large mammals, such as bears and domesticated horses, eat apples and spread the seeds today. However, prior to the end of the last Ice Age, there were many more large mammals on the European landscape, such as wild horses and large deer. Evidence suggests that seed dispersal in the large-fruiting wild relatives of the apple has been weak during the past ten thousand years, since many of these animals went extinct. The fact that wild apple populations appear to map over glacial refugial zones of the Ice Age further suggests that these plants have not been moving over long distances or colonizing new areas in the absence of their original seed-spreaders.

Trade along the Silk Road likely enabled the development of the apple we know today

Silk Road apple
Venders in every Central Asian bazaar sell a diverse array of apples. This women in the Bukhara bazaar is selling a variety of small sweet yellow apples, which she locally cultivated in Uzbekistan. Some of the fruits sold in these markets today travel great distances, similar to how they would have during the peak of the Silk Road. Credit: Robert Spengler

Wild apple tree populations were isolated after the end of the last Ice Age, until humans started moving the fruits across Eurasia, in particular along the Silk Road. Once humans brought these tree lineages back into contact with each other again, bees and other pollinators did the rest of the work. The resulting hybrid offspring had larger fruits, a common result of hybridization. Humans noticed the larger fruiting trees and fixed this trait in place through grafting and by planting cuttings of the most favored trees. Thus, the apples we know today were primarily not developed through a long process of the selection and propagation of seeds from the most favored trees, but rather through hybridization and grafting. This process may have been relatively rapid and parts of it were likely unintentional. The fact that apple trees are hybrids and not "properly" domesticated is why we often end up with a crabapple tree when we plant an apple seed.

This study challenges the definition of "domestication"' and demonstrates that there is no one-shoe-fits-all model to explain plant evolution under human cultivation. For some plants, domestication took millennia of cultivation and human-induced selective pressure - for other plants, hybridization caused rapid morphological change. "The domestication process is not the same for all plants, and we still do not know much about the process in long-generation trees," notes Spengler. "It is important that we look past annual grasses, such as wheat and rice, when we study plant domestication. There are hundreds of other domesticated plants on the planet, many of which took different pathways toward domestication." Ultimately, the apple in your kitchen appears to owe its existence to extinct megafaunal browsers and Silk Road merchants.

 

 

Press release from the Max Planck Institute for the Science of Human History / Max-Planck-Institut für Menschheitsgeschichte


imitation amber pine resin Iberian peninsula

First examples of Iberian prehistoric 'imitation amber' beads at gravesites

First examples of Iberian prehistoric 'imitation amber' beads at gravesites

Unscrupulous traders might have cheated rich customers with fake amber beads

imitation amber beads pine resin Iberian peninsula
These are amber bead samples studied in this paper. Credit: Odriozola et al., 2019, CC BY

Prehistoric Iberians created "imitation amber" by repeatedly coating bead cores with tree resins, according to a study published May 1, 2019 in the open-access journal PLOS ONE by Carlos Odriozola from Universidad de Sevilla, Spain, and colleagues.

Many studies have confirmed the ornamental and symbolic importance of amber to European prehistoric peoples. This study is the first to discuss potential prehistoric Iberian "imitation amber" beads made using the application of repeated resinite coatings on top of a bead core.

The authors obtained beads from two prehistoric sites in Spain: two from a cave tomb at the La Molina site in Sevilla, dating from the 3rd millennium BC, and four from a burial site in Cova del Gegant near Barcelona, dating from the 2nd millennium BC. Using infrared spectroscopy, an electron microscope probe, x-ray diffraction, and spectroscopy, the authors were able to study the chemical composition and structure of all six bead cores and coatings.

The beads from Cova del Gegant had a mollusk shell core, covered by a multilayered coating made up of tree resins, most likely pine. The beads were covered by a calcium-containing white deposit, which likely precipitated post-burial from the bone tissue of buried individuals. The beads from La Molina were also composed of a core covered by an amber-like resin, as well as two topmost layers of cinnabar and calcite which probably coated the beads post-burial.

The authors speculate these coating technologies were used to imitate amber's translucence, shine, and color, since during this prehistoric period, amber was relatively rare and highly in demand. However, both tomb sites contained other exotic materials such as ivory, gold and cinnabar, so it's not clear why individuals able to obtain these rare goods would use amber alternatives. The authors speculate that, especially in the Cova del Gegant where "imitation amber" was found directly alongside true amber beads, unscrupulous traders may have substituted low-cost fake amber to cheat their buyers. The authors also suggest chemical analysis of apparent "amber" artifacts could prevent erroneous amber identification in future studies of such Iberian sites.

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Citation: Odriozola CP, Garrido Cordero JÁ, Daura J, Sanz M, Martínez-Blanes JM, Avilés MÁ (2019) Amber imitation? Two unusual cases of Pinus resin-coated beads in Iberian Late Prehistory (3rd and 2nd millennia BC). PLoS ONE 14(5): e0215469. https://doi.org/10.1371/journal.pone.0215469

Funding: This research was funded by the MINECO/AEI/FEDER -EU under contract HAR2012-34620 and HAR2017-83474-P. José Ángel Garrido Cordero acknowledges the University of Seville for a PhD grant under the V Plan Propio de Investigación de la Universidad de Sevilla. Montserrat Sanz acknowledges the program Juan de la Cierva for a postdoctoral grant (FJCI-2014-21386). Daura holds a postdoctoral grant (SFRH/BPD/ 100507/2014?) from the Portuguese Fundação para a Ciência e a Tecnologia using funding from the FSE/POPH.

Competing Interests: The authors have declared that no competing interests exist.

 

Press release from the Public Library of Sciences (PLOS)