Gaited horses most likely originated in the 9th century medieval England

Some horses have special gaits, which are more comfortable for the rider than walk, trot or gallop. Now, a study by an international research team under the direction of the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin revealed that these gaited horses most likely originated in the 9th century medieval England. From there they were brought to Iceland by the Vikings and later spread all over Europe and Asia. These findings were published in the current issue of the journal "Current Biology."

Walk, trot and gallop are the gaits which all horses can master. However, riders who want to sit in their saddle more comfortably while still making good time on long journeys would benefit from choosing gaited horses. They are able to perform special gaits, like the ambling or pacing, which are typical for Icelandic horses and allow for a smoother ride. Responsible for this ability is a mutation in the DMRT3 gene, which was recently shown by a study with over 4,000 horses from different breeds. To investigate the history of gaited horses the scientist analysed this mutation in the genome of 90 horses from the Copper Age (6000 BC) to the Middle Ages (11th century). They detected the mutation in samples of two English horses from 850 -- 900 AD and more frequently in Icelandic horses dating to the 9th -- 11th century. Most likely the first gaited horses appeared in medieval England and were then transported to Iceland by the Vikings. Horses have existed in Iceland since 870 BC. In contrast, no European (Scandinavia included) or Asian horse of the same period carrying the mutation for the alternative gaits was found.

It is improbable that the English and Icelandic gaited horse populations developed independently from each other in such a short time. "It is much more likely, that the first horses ever imported to Iceland already carried the mutation for alternative gaits. The Vikings recognised the value of the gaited horses and preferentially selected for this trait -- thereby laying the foundation for the worldwide distribution," explains Arne Ludwig, geneticist at the IZW. 

Historic sagas also suggest that Icelandic horses exhibited the ability for alternative gaits at a very early stage. Although the origin of the Icelandic horse is not fully resolved, the general assumption is that they came to the island together with the Vikings. However, since the mutation was not found in Scandinavian horses of the 9th century, horses from other regions must have been brought to Iceland as well.

Historic records report that Vikings were repeatedly pillaging on the British Isles and conquered the region of today's Yorkshire -- precisely the region the two historic gaited horses originated from. "Taking that into account our results suggest that Vikings first encountered gaited horses on the British Isles and transported them to Iceland," explains Saskia Wutke, PhD student at the IZW and first lead author of the study. The high frequency of the mutation for gaitedness in the early Icelandic horses indicates that the Icelandic settlers preferably bred gaited horses -- apparently the comfortable gaits proved to be particularly suitable for long distance travel through rough terrain.

Fresh look at burials, mass graves, tells a new story of Cahokia

A new study challenges earlier interpretations of an important burial mound at Cahokia, a pre-Columbian city in Illinois near present-day St. Louis. The study reveals that a central feature of the mound, a plot known as the "beaded burial," is not a monument to male power, as was previously thought, but includes both males and females of high status.

The new study, published in the journal American Antiquity, is one of several recent analyses of the site from researchers at the Illinois State Archaeological Survey at the University of Illinois and their colleagues at other institutions. All of the studies confirm the presence of males and females in the beaded burial.

In 1967, archaeologist Melvin Fowler discovered a massive burial site at Cahokia while excavating an unusual, ridgetop mound. This mound, now called Mound 72, held five mass graves, each containing 20 to more than 50 bodies, with dozens of other bodies buried individually or in groups, sometimes directly over the mass graves. Fowler identified 270 bodies in the mound.

Beaded burial at Cahokia.
CREDIT
Graphic: Julie Mahon

Scientists later determined that all of the burials occurred between about 1000 and 1200, during the rise and peak of Cahokia's power and influence. Some of the burials appeared to be high-status individuals whose bodies were placed on cedar litters.

"Mound 72 burials are some of the most significant burials ever excavated in North America from this time period," said ISAS director Thomas Emerson, who conducted the most recent study with physical anthropologist Kristin Hedman and skeletal analysts Eve Hargrave of ISAS, Dawn Cobb of the Illinois State Museum Society, and Andrew Thompson of the University of Cincinnati College of Medicine. The ISAS is a division of the Prairie Research Institute at Illinois.

"Fowler's and others' interpretation of these mounds became the model that everybody across the east was looking at in terms of understanding status and gender roles and symbolism among Native American groups in this time," Emerson said.

Emerson and his colleagues discovered that some of those early interpretations were based on inaccurate and incomplete information. Most of the errors involved the beaded burial. Here, two central bodies were placed, one on top of the other, on a partial bed of beads that also ran between and around the bodies. Several other bodies, buried at the same time, were arranged around this pair.

Fowler and later archaeologists came to believe that this was a burial of two high-status males surrounded by their servants. They interpreted the arrangement of beads associated with these central figures as the remains of a beaded cape or blanket in the shape of a bird. The pattern of beads near the heads of the two central bodies resembled a bird head, some thought.

Because the bird is a common motif related to warriors and supernatural beings in some Native American traditions, Fowler proposed that the central males of the beaded burial represented mythical warrior chiefs.

"One of the things that promoted the concept of the male warrior mythology was the bird image," Emerson said. Once this interpretation took hold, many researchers came to see this as evidence that Cahokia was "a male-dominated hierarchy," he said.

A fresh look at the early archaeologists' maps, notes and reports and the skeletal remains told a new and surprising story. First, the researchers found that there were 12 bodies associated with the beaded burial - not six, as had been previously reported. And independent skeletal analyses conducted by each of the co-authors - Thompson, Hedman, Hargrave and Cobb - revealed that the two central bodies in the beaded burial were actually male and female.

Further analyses revealed other male-female pairs on top of, and near, the beaded area. Some were laid out as fully articulated bodies. Others were disarticulated bodies, the bones of which had been gathered and bundled for burial near these important couples. The researchers also discovered the remains of a child.

"We had been checking to make sure that the individuals we were looking at matched how they had been described," Hedman said. "And in re-examining the beaded burial, we discovered that the central burial included females. This was unexpected."

"The fact that these high-status burials included women changes the meaning of the beaded burial feature," Emerson said. "Now, we realize, we don't have a system in which males are these dominant figures and females are playing bit parts. And so, what we have at Cahokia is very much a nobility. It's not a male nobility. It's males and females, and their relationships are very important."

The new findings are more in line with other evidence from Cahokia, Emerson said.

"For me, having dug temples at Cahokia and analyzed a lot of that material, the symbolism is all about life renewal, fertility, agriculture," he said. "Most of the stone figurines found there are female. The symbols showing up on the pots have to do with water and the underworld. And so now Mound 72 fits into a more consistent story with what we know about the rest of the symbolism and religion at Cahokia."

Emerson said that those who saw warrior symbolism at Cahokia missed the special culture of the time period.

"When the Spanish and the French came into the southeast as early as the 1500s, they identified these kinds of societies in which both males and females have rank," he said. "Really, the division here is not gender; it's class."

"People who saw the warrior symbolism in the beaded burial were actually looking at societies hundreds of years later in the southeast, where warrior symbolism dominated, and projecting it back to Cahokia and saying: 'Well, that's what this must be,'" Emerson said. "And we're saying: 'No, it's not.'"

Other recent findings related to the people buried in Mound 72 are described in the Journal of Archaeological Science, the American Journal of Physical Anthropology, and a chapter in the book "Beyond Collapse: Archaeological Perspectives on Resilience, Revitalization and Transformation in Complex Societies."


VIDEO https://www.youtube.com/watch?v=ESmAa1CGO68

Residual remains of butchered animals on stone tools used 250,000 years ago in Jordan

How smart were human-like species of the Stone Age? New research published in the Journal of Archaeological Science by a team led by paleoanthropologist April Nowell of the University of Victoria reveals surprisingly sophisticated adaptations by early humans living 250,000 years ago in a former oasis near Azraq, Jordan.

The research team from UVic and partner universities in the US and Jordan has found the oldest evidence of protein residue -- the residual remains of butchered animals including horse, rhinoceros, wild cattle and duck -- on stone tools. The discovery draws startling conclusions about how these early humans subsisted in a very demanding habitat, thousands of years before Homo sapiens first evolved in Africa.

The team excavated 10,000 stone tools over three years from what is now a desert in the northwest of Jordan, but was once a wetland that became increasingly arid habitat 250,000 years ago. The team closely examined 7,000 of these tools, including scrapers, flakes, projectile points and hand axes (commonly known as the "Swiss army knife" of the Paleolithic period), with 44 subsequently selected as candidates for testing. Of this sample, 17 tools tested positive for protein residue, i.e. blood and other animal products.

"Researchers have known for decades about carnivorous behaviours by tool-making hominins dating back 2.5 million years, but now, for the first time, we have direct evidence of exploitation by our Stone Age ancestors of specific animals for subsistence," says Nowell. "The hominins in this region were clearly adaptable and capable of taking advantage of a wide range of available prey, from rhinoceros to ducks, in an extremely challenging environment."

"What this tells us about their lives and complex strategies for survival, such as the highly variable techniques for prey exploitation, as well as predator avoidance and protection of carcasses for food, significantly diverges from what we might expect from this extinct species," continues Nowell. "It opens up our ability to ask questions about how Middle Pleistocene hominins lived in this region and it might be a key to understanding the nature of interbreeding and population dispersals across Eurasia with modern humans and archaic populations such as Neanderthals."

Another result of this study is the potential to revolutionize what researchers know about early hominin diets. "Other researchers with tools as old or older than these tools from sites in a variety of different environmental settings may also have success when applying the same technique to their tools, especially in the absence of animal remains at those sites," adds Nowell.

Why people in eastern North America domesticated plants for the first time about 5,000 years ago

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This map shows the area covered by a new University of Utah study that concludes a population boom and resulting scarcity of wild foods are what caused early people in eastern North America to domesticate wild food plants for the first time on the continent starting about 5,000 year ago. The triangles and names represent archaeological sites previously identified as locations where one or more of the these plants first were domesticated: squash, sunflower, marshelder and pitseed goosefoot, a relative of quinoa. The small circles are sites where radiocarbon-dated artifacts have been found, with a single circle often representing many dated artifacts. The study area includes much of eastern North America inland from the Atlantic and Gulf coasts. 

Credit: Elic Weitzel, University of Utah

University of Utah anthropologists counted the number of carbon-dated artifacts at archaeological sites and concluded that a population boom and scarce food explain why people in eastern North America domesticated plants for the first time on the continent about 5,000 years ago.

"Domesticated plants and animals are part of our everyday lives, so much so that we take them for granted," says Brian Codding, senior author of the study published online August 2 by the British journal Royal Society Open Science. "But they represent a very unique thing in human history. They allowed for large numbers of people to live in one place. That ultimately set the stage for the emergence of civilization."

Graduate student Elic Weitzel, the study's first author, adds: "For most of human history, people lived off wild foods -- whatever they could hunt or gather. It's only relatively recently that people made this switch to a very different method of acquiring their food. It's important to understand why that transition happened."

The study dealt not with a full-fledged agricultural economy, but with the earlier step of domestication, when early people in eastern North America first started growing plants they had harvested in the wild, namely, squash, sunflower, marshelder and a chenopod named pitseed goosefoot, a pseudocereal grain closely related to quinoa.

Codding, an assistant professor of anthropology, says at least 11 plant domestication events have been identified in world history, starting with wheat about 11,500 years ago in the Middle East. The eastern North American plant domestication event, which began around 5,000 years ago, was the ninth of those 11 events and came after a population boom 6,900 to 5,200 years ago, he adds.

For many years, two competing theories have sought to explain the cause of plant domestication in eastern North America: First, population growth and resulting food scarcity prompted people to grow foods on which they already foraged. Second, a theory called "niche construction" or "ecosystem engineering" that basically says intentional experimentation and management during times of plenty -- and not immediate necessity -- led people to manage and manipulate wild plants to increase their food supply.

"We argue that human populations significantly increased prior to plant domestication in eastern North America, suggesting that people are driven to domestication when populations outstrip the supply of wild foods," Weitzel says.

"The transition to domesticating food allowed human populations to increase drastically around the world and made our modern way of life possible," he adds. "People start living near the fields. Whenever you've got sedentary communities, they start to expand. Villages expand into cities. Once you have that, you have all sorts of social changes. We really don't see state-level society until domestication occurs."

When early North Americans first domesticated crops

The region of eastern North America covered by the study includes most of Missouri, Illinois, Indiana, Ohio, West Virginia, Kentucky, Tennessee and Arkansas, and portions of Oklahoma, Kansas, Iowa, Virginia, North Carolina, South Carolina, Georgia, Mississippi and Louisiana.

"This is the region where these plant foods were domesticated from their wild variants," Weitzel says. "Everywhere else in North America, crops were imported from elsewhere," particularly Mexico and Central America.

Four indigenous plant species constitute what scientists call the Eastern Agricultural Complex, which people began to domesticate about 5,000 years ago.

Previous research shows specific domestication dates were 5,025 years ago for squash at an archaeological site named Phillips Spring in Missouri, 4,840 years ago for sunflower seeds domesticated at Hayes in Tennessee, 4,400 years ago for marshelder at the Napoleon Hollow site in Illinois, and 3,800 years ago for pitseed goosefoot found in large quantities at Riverton, Illinois, along with squash, sunflower and marshelder.

Three more recent sites also have been found to contain evidence of domestication of all four species: Kentucky's Cloudsplitter and Newt Kindigenash rockshelters, dated to 3,700 and 3,640 years ago, respectively, and the 3,400-year-old Marble Bluff site in Arkansas.

Sunflower and squash -- including acorn and green and yellow summer squashes -- remain important crops today, while marshelder and pitseed goosefoot are not (although the related quinoa is popular).

Deducing population swings from radiocarbon dates

"It's really difficult to arrive at measures of prehistoric populations. So archaeologists have struggled for a long time coming up with some way of quantifying population levels when we don't have historical records," Weitzel says.

"People have looked at the number of sites through time, the number of artifacts through time and some of the best work has looked at the effects of population growth," such as in the switch from a diet of tortoises to rabbits as population grew in the eastern Mediterranean during the past 50,000 years, he adds.

Codding says that in the past decade, archaeologists have expanded the use of radiocarbon-dates for artifacts to reconstruct prehistoric population histories. Weitzel says radiocarbon dates in the new study came from artifacts such as charcoal, nutshells and animal bones -- all recorded in a database maintained by Canadian scientists.

The University of Utah anthropologists used these "summed radiocarbon dates" for 3,750 dated artifacts from eastern North America during the past 15,000 years.

"The assumption is that if you had more people, they left more stuff around that could be dated," Weitzel says. "So if you have more people, you conceivably should have more radiocarbon dates."
"We plotted the dates through time," namely, the number of radiocarbon dates from artifacts in every 100-year period for the past 15,000 years, he adds.

The analysis indicated six periods of significant population increase or decrease during that time, including one during which population nearly doubled in eastern North America starting about 6,900 years ago and continuing apace until 5,200 years ago -- not long before plant domestication began, Codding says.

Codding notes that even though plant domestication meant "these people were producing food to feed themselves and their families, they're still hunting and foraging," eating turtles, fish, water fowl and deer, among other animals.

The other theory

Weitzel says the concept of niche construction is that people were harvesting wild plants, and "were able to get more food from certain plants." By manipulating the environment -- such as transplanting wild plants or setting fires to create areas favorable for growth of wild food plants -- they began "experimenting with these plants to see if they could grow them to be bigger or easier to collect and consume," he adds. "That kind of experimentation then leads to domestication."

Codding says: "The idea is that when times are good and people have plenty of food then they will experiment with plants. We say that doesn't provide an explanation for plant domestication in eastern North America." He believes the behavioral ecology explanation: increasing population and-or decreasing wild food resources led to plant domestication.

Historic Find at Tel-Hazor: A Statue of an Egyptian Official

In a historic find, a large fragment of an Egyptian statue measuring 45 X 40 centimeters, made of lime-stone, was discovered In the course of the current season of excavations at Tel-Hazor, north of the Sea of Galilee in Israel. Only the lower part of the statue survived, depicting the crouching feet of a male figure, seated on a square base on which a few lines in the Egyptian hieroglyphic script are inscribed.


The archaeologists estimate that the complete statue would equal the size of a fully-grown man. At present only a preliminary reading of the inscriptions has been attempted, and the title and name of the Egyptian official who originally owned the statue, are not yet entirely clear.

The statue was originally placed either in the official's tomb or in a temple – most probably a temple of the Egyptian god Ptah – and most of the texts inscribed on the statue's base include words of praise to the official who may have served and most probably practiced his duties in the region of Memphis, the primary cult center of the god Ptah. They also include the customary Egyptian funerary formula ensuring eternal supply of offerings for the statue's owner. This statue, found this year, together with the sphinx fragment of the Egyptian king Mycerinus (who ruled Egypt in the 25th century B.C.E.) discovered at the site by the research team three years ago, are the only monumental Egyptian statues found so far in second millennium contexts in the entire Levant.

The discovery of these two statues in the same building currently being excavated by the research team, indicates the special importance of the building (probably the administrative palace of the ruler of the city), as well as that of the entire city of Hazor.

According to Prof. Amnon Ben-Tor of the Institute of Archaeology at the Hebrew University of Jerusalem, who has been conducting excavations at Tel-Hazor for over 27 years, Hazor is the most important site from the Biblical period. Shlomit Bechar, a doctoral student at the Institute of Archaeology who has been excavating at Hazor for a decade, is co-director of the Hazor excavations and director of the main excavation area.

In the course of close to 30 years of excavation, fragments of 18 different Egyptian statues, both royal and private, dedicated to Egyptian kings and officials, including two sphinxes, were discovered at Hazor. Most of these statues were found in layers dated to the Late Bronze Age (15th-13th centuries B.C.E.) – corresponding to the New Kingdom in Egypt. This is the largest number of Egyptian statues found so far in any site in the Land of Israel, although there is no indication that Hazor was one of the Egyptian strongholds in Southern Canaan nor of the presence of an Egyptian official at Hazor during the Late Bronze Age.

Interestingly, most Egyptian statues found at Hazor so far date to Egypt's "Middle Kingdom" (19th-18th centuries B.C.E), a time when Hazor did not yet exist. It thus seems that the statues were sent by an Egyptian king in the "New Kingdom" as official gifts to the king of Hazor, or as dedications to a local temple (regardless of their being already "antiques"). This is not surprising considering the special status of the king of Hazor who was the most important king in Southern Canaan at the time. The extraordinary importance of Hazor in the 15th-13th centuries B.C.E. is indicated also by the Biblical reference to Hazor as "the head of all those kingdoms" (Joshua 11:10).

All the statues at the site were found broken to pieces and scattered over a large area. Clear signs of mutilation indicate that most of them were deliberately and violently smashed, most probably in the course of the city's final conquest and destruction sometime in the 13th century B.C.E. The deliberate mutilation of statues of kings and dignitaries accompanying the conquest of towns, is a well-known practice in ancient times (I Samuel 5:1-4; Isaiah 11:9) as well as in our time.

The Hazor excavations, which began in the mid 1950 (under the direction of the late Prof. Yigael Yadin), are carried out on behalf of the Hebrew University of Jerusalem. The excavations were resumed in 1990 – still on behalf of the Hebrew University, and the Israel Exploration Society, and are named "The Selz Foundation Hazor Excavations in Memory of Yigael Yadin". The excavation takes place within the Hazor National Park, in full support and cooperation with the National Parks Authority.

The three volunteer excavators who found the statue, from left to right: Valentin Sama-Rojo from Spain, Bryan Kovach from the United States, and Elanji Swart from South Africa. (Photo credit: Shlomit Bechar)

Hazor is the largest biblical-era site in Israel, covering some 200 acres, and has been recognized as a World Heritage Site by UNESCO. The population of Hazor in the second millennium BCE is estimated to have been about 20,000, making it the largest and most important city in the entire region. Its size and strategic location on the route connecting Egypt and Babylon made it "the head of all those kingdoms" according to the biblical book of Joshua (Joshua 11:10). Hazor's conquest by the Israelites opened the way to the conquest and settlement of the Israelites in Canaan. The city was rebuilt and fortified by King Solomon and prospered in the days of Ahab and Jeroboam II, until its final destruction by the Assyrians in 732 BCE.

Documents discovered at Hazor and at sites in Egypt and Iraq attest that Hazor maintained cultural and trade relations with both Egypt and Babylon. Artistic artifacts, including those imported to Hazor from near and far, have been unearthed at the site. Hazor is currently one of Israel's national parks.

Evidence of earliest cancer in homonin record found on South African fossils

An international team of researchers led by scientists from the University of the Witwatersrand's Evolutionary Studies Institute and the South African Centre for Excellence in PalaeoSciences today announced in two papers, published in the South African Journal of Science, the discovery of the most ancient evidence for cancer and bony tumours yet described in the human fossil record.

Volume rendered image of the external morphology of the foot bone shows the extent of expansion of the primary bone cancer beyond the surface of the bone.
CREDIT
Patrick Randolph-Quinney (UCLAN)

The discovery of a foot bone dated to approximately 1.7 million years ago from the site of Swartkrans with definitive evidence of malignant cancer, pushes the oldest date for this disease back from recent times into deep prehistory. Although the exact species to which the foot bone belongs is unknown, it is clearly that of a hominin, or bipedal human relative.

In an accompanying paper appearing in the same journal, a collaborating team of scientists identify the oldest tumour ever found in the human fossil record, a benign neoplasm found in the vertebrae of the well-known Australopithecus sediba child, Karabo from the site of Malapa, and dated to almost two million years in age. The oldest previously demonstrated possible hominin tumour was found in the rib of a Neanderthal and dated to around 120,000 years old.

Edward Odes, a Wits doctoral candidate and lead author of the cancer paper, and co-author on the tumour paper, notes "Modern medicine tends to assume that cancers and tumours in humans are diseases caused by modern lifestyles and environments. Our studies show the origins of these diseases occurred in our ancient relatives millions of years before modern industrial societies existed".

The cancer in a foot bone, a metatarsal, was identified as an osteosarcoma, an aggressive form of cancer which usually affects younger individuals in modern humans, and, if untreated typically results in early death. "Due to its preservation, we don't know whether the single cancerous foot bone belongs to an adult or child, nor whether the cancer caused the death of this individual, but we can tell this would have affected the individuals' ability to walk or run," says Dr Bernhard Zipfel, a Wits scientist and an expert on the foot and locomotion of early human relatives. "In short, it would have been painful."

Lead author of the tumour paper and co-author of the cancer paper, Dr Patrick Randolph-Quinney of Wits University and the University of Central Lancashire in the UK, suggests "The presence of a benign tumour in Australopithecus sediba is fascinating not only because it is found in the back, an extremely rare place for such a disease to manifest in modern humans, but also because it is found in a child. This, in fact, is the first evidence of such a disease in a young individual in the whole of the fossil human record".

Prof. Lee Berger, an author on both papers and leader of the Malapa project where the fossil vertebra was found adds "not only has there been an assumption that these sorts of cancers and tumours are diseases of modernity, which these fossils clearly demonstrate they are not, but that we as modern humans exhibit them as a consequence of living longer, yet this rare tumour is found in a young child. The history of these types of tumours and cancers is clearly more complex than previously thought".

Both incidences of disease were diagnosed using state of the art imaging technologies including those at the European Synchrotron Research Facility in Grenoble, France, medical CT at the Charlotte Maxeke Hospital in Johannesburg, and the micro-CT facility at the Nuclear Energy Corporation of South Africa at Pelindaba.

"Researchers in South Africa are at the forefront of using various X-Ray modalities to discover new and interesting facts about ancient human relatives," notes Dr Jacqueline Smilg, a radiologist based at Charlotte Maxeke Hospital, who is an author on both papers and was involved in the clinical diagnoses. "This is another good example of how the modern clinical sciences and the science of palaeoanthropology are working together in South Africa and with international collaborators to advance our understanding of diseases in both the past and the present."

Genome of 6,000-year-old barley grains retrieved from Yoram Cave in the southern cliff of Masada fortress sequenced

An international team of researchers has succeeded for the first time in sequencing the genome of Chalcolithic barley grains. This is the oldest plant genome to be reconstructed to date. The 6,000-year-old seeds were retrieved from Yoram Cave in the southern cliff of Masada fortress in the Judean Desert in Israel, close to the Dead Sea. Genetically, the prehistoric barley is very similar to present-day barley grown in the Southern Levant, supporting the existing hypothesis of barley domestication having occurred in the Upper Jordan Valley.

The analyzed grains, together with tens of thousands of other plant remains, were retrieved during a systematic archaeological excavation headed by Uri Davidovich, from the Institute of Archaeology, The Hebrew University of Jerusalem, and Nimrod Marom, from Zinman Institute of Archaeology, University of Haifa, Israel. The archaeobotanical analysis was led by Ehud Weiss, of Bar-Ilan University. The cave is very difficult to access and was used only for a short time by humans, some 6,000 years ago, probably as ephemeral refuge.

Oldest plant genome reconstructed to date

Most examination of archaeobotanical findings has been limited to the comparison of ancient and present-day specimens based on their morphology. Up to now, only prehistoric corn has been genetically reconstructed. In this research, the team succeeded in sequencing the complete genome of the 6,000-year-old barley grains. The results are now published in the online version of the journal Nature Genetics.

"These archaeological remains provided a unique opportunity for us to finally sequence a Chalcolithic plant genome. The genetic material has been well-preserved for several millennia due to the extreme dryness of the region," explains Ehud Weiss, of Bar-Ilan University. In order to determine the age of the ancient seeds, the researchers split the grains and subjected half of them to radiocarbon dating while the other half was used to extract the ancient DNA. "For us, ancient DNA works like a time capsule that allows us to travel back in history and look into the domestication of crop plants at distinct time points in the past," explains Johannes Krause, Director of the Department of Archaeogenetics at the Max Planck Institute for the Science of Human History in Jena. The genome of Chalcolithic barley grains is the oldest plant genome to be reconstructed to date.

Domestication of barley completed very early

Wheat and barley were already grown 10,000 years ago in the Fertile Crescent, a sickle-shaped region stretching from present-day Iraq and Iran through Turkey and Syria into Lebanon, Jordan and Israel. Up to this day, the wild forms of these two crops persist in the region and are among the major model species studied at the Institute of Evolution in the University of Haifa. "It was from there that grain farming originated and later spread to Europe, Asia and North Africa," explains Tzion Fahima, of the University of Haifa.

"Our analyses show that the seeds cultivated 6,000 years ago greatly differ genetically from the wild forms we find today in the region. However, they show considerable genetic overlap with present-day domesticated lines from the region," explains Nils Stein, who directed the comparison of the ancient genome with modern genomes at the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, with the support of Robbie Waugh and colleagues at the James Hutton Institute, Dundee, Scotland, and Gary Muehlbauer, University of Minnesota, USA. "This demonstrates that the domestication of barley in the Fertile Crescent was already well advanced very early."

The comparison of the ancient seeds with wild forms from the region and with so-called 'landraces' (i.e., local barley lines grown by farmers in the Near East) enabled to geographically suggest, according to Tzion Fahima and his colleagues at the University of Haifa and Israel's Tel-Hai College, "the origin of the domestication of barley within the Upper Jordan Valley - a hypothesis that is also supported by two archaeological sites in the surrounding area where the hitherto earliest remains of barley cultivation have been found.

Immigrants "trust" in extant landraces

Also the genetic overlap with present-day domesticated lines from the region is revealing to the researchers. "This similarity is an amazing finding considering to what extent the climate, but also the local flora and fauna, as well as the agricultural methods, have changed over this long period of time," says Martin Mascher, from the Leibniz Institute of Plant Genetics and Crop Plant Research, the lead author of the study. The researchers therefore assume that conquerors and immigrants coming to the region did not bring their own crop seeds from their former homelands, but continued cultivating the locally adapted extant landraces.

New insights into the origins of our crop plants

Combining archaeology, archaeobotany, genetics and computational genomics in an interdisciplinary study has produced novel insights into the origins of our crop plants. "This is just the beginning of a new and exciting line of research," predicts Verena Schuenemann, from Tuebingen University, the second lead author of the study. "DNA-analysis of archaeological remains of prehistoric plants will provide us with novel insights into the origin, domestication and spread of crop plants."