Max Planck Institute for the Science of Human History

Jena, Germany

Max Planck Institute for the Science of Human History

Jena, Germany
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According to new research, nomadic horse culture -- famously associated with Genghis Khan and his Mongol hordes -- can trace its roots back more than 3,000 years in the eastern Eurasian Steppes, in the territory of modern Mongolia (Figure 1). The study, published online March 31 in Journal of Archaeological Science, produces scientific estimates of the age of horse bones found from archaeological sites belonging to a culture known as the Deer Stone-Khirigsuur Complex. This culture, named for the beautiful carved standing stones ("deer stones") and burial mounds (khirigsuurs) it built across the Mongolian Steppe (Figure 2), is linked with some of the oldest evidence for nomadic herding and domestic livestock use in eastern Eurasia. At both deer stones and khirigsuurs, stone mounds containing ritual burials of domestic horses - sometimes numbering in the hundreds or thousands - are found buried around the edge of each monument (Figure 3). A team of researchers from several academic institutions - including the Max Planck Institute for the Science of Human History, Yale University, University of Chicago, the American Center for Mongolian Studies, and the National Museum of Mongolia - used a scientific dating technique known as radiocarbon dating to estimate the spread of domestic horse ritual at deer stones and khirigsuurs. When an organism dies, an unstable radioactive molecule present in living tissues, known as radiocarbon, begins to decay at a known rate. By measuring the remaining concentration of radiocarbon in organic materials, such as horse bone, archaeologists can estimate how many years ago an animal took its final step. Many previous archaeological projects in Mongolia produced radiocarbon date estimates from horse remains found at these Bronze Age archaeological sites. However, because each of these measurements must be calibrated to account for natural variation in the environment over time, individual dates have large amounts of error and uncertainty, making them difficult to aggregate or interpret in groups. By using a statistical technique known as Bayesian analysis - which combines probability with archaeological information to improve precision for groups of radiocarbon dates - the study authors were able to produce a high-precision chronology model for early domestic horse use in Mongolia. Lead author William Taylor, a postdoctoral research fellow at the Max Planck Institute for the Science of Human History, says that this model "enables us for the first time to link horse use with other important cultural developments in ancient Mongolia and eastern Eurasia, and evaluate the role of climate and environmental change in the local origins of horse riding." According to the study, domestic horse ritual spread rapidly across the Mongol Steppe at around 1200 BC - several hundred years before mounted horsemen are clearly documented historical records. When considered alongside other evidence for horse transport in the Deer Stone-Khirigsuur Complex these results suggest that Mongolia was an epicenter for early horse culture - and probably early mounted horseback riding. The study has important consequences for our understanding of human responses to climate change. For example, one particularly influential hypothesis argues that horse riding and nomadic herding societies developed during the late second millennium BCE, as a response to drought and a worsening climate. Taylor and colleagues' results indicate instead that early horsemanship took place during a wetter, more productive climate period - which may have given herders more room to experiment with horse breeding and transport. In recent years, scholars have become increasingly aware of the role played by Inner Asian nomads in early waves of globalization. A key article by Dr. Michael Frachetti and colleagues, published this month in Nature argues that nomadic movement patterns shaped the early trans-Eurasian trade networks that would eventually move goods, people, and information across the continent. The development of horsemanship by Mongolian cultures might have been one of the most influential changes in Eurasian prehistory - laying the groundwork for the economic and ecological exchange networks that defined the Old World for centuries to come.


News Article | May 17, 2017
Site: www.eurekalert.org

The study -- coordinated by the Human Biodiversity and Population Genomics group at the Department of Biological, Geological and Environmental Sciences (BiGeA) of the University of Bologna and funded by the National Geographic Society -- describes the genetic fingerprints of the Mediterranean people with high-density genomic markers and a wide sample of modern populations from Sicily and Southern Italy. Their genetic profiles were analyzed to reconstruct the combination of ancestry components and the demographic history of the region. As one would expect, populations inhabiting the southeastern shores of Europe are the result of a complex, multi-layered history. One of these layers corresponds to a shared genetic background, extending from Sicily to Cyprus and involving Crete, the Aegean islands and Anatolia. "This shared Mediterranean ancestry possibly traces back to prehistoric times, as the result of multiple migration waves, with peaks during the Neolithic and the Bronze Age," says Stefania Sarno, researcher from the University of Bologna and lead author of the study. Apparently, the ancient Greek expansions (during the Magna Graecia foundation) were only one of the last events in a long history of East-West movements, where the Mediterranean Sea served as a preferential crossroads for the circulation of genes and cultures. A new perspective for the diffusion of Indo-European languages One of the most intriguing layers hidden in the Mediterranean genetic landscape involves an important Bronze Age contribution from a Caucasus (or Caucasus-like) source, accompanied by the virtual absence of the typical "Pontic-Caspian" genetic component from the Asian steppe. The latter is a very characteristic genetic signal well represented in North-Central and Eastern Europe, which previous studies associated with the introduction of Indo-European languages to the continent. "These new genomic results from the Mediterranean open a new chapter for the study of the prehistoric movements behind the diffusion of the most represented language family in Europe. The spread of these languages in the Southern regions, where Indo-European languages like Italian, Greek and Albanian are spoken nowadays, cannot be explained with the major contribution from the steppe alone," adds Chiara Barbieri from the Max Planck Institute for the Science of Human History in Jena. The current genetic study also focuses on more recent historical layers that contributed to the present-day genetic makeup of the populations sampled, in particular in the cases of long-standing, non-Italian-speaking communities in Italy. For example, mainland Greece and Albania seem to have acquired additional genetic contributions during historic times, most likely related to the Slavic migrations in the Balkans. This recent Balkan genetic ancestry is still evident in some ethno-linguistic minorities of Sicily and Southern Italy, such as the Albanian-speaking Arbereshe. The Arbreshe migrated from Albania to Italy at the end of the Middle Ages and experienced geographic and cultural isolation, which played a part in their distinctive genetic composition. A different case study is that of Greek-speaking communities from Southern Italy. The genetic features of these groups are compatible with the antiquity of their settlement and with a high cultural permeability with neighboring populations, combined with drift and effects of geographic isolation, as in the case of Calabrian Greeks. "The study of linguistic and cultural isolates in Italy proved to be important to understand our history and our demography," says Alessio Boattini, geneticist and anthropologist from the University of Bologna. "The cases of the Albanian- and Greek-speaking communities of Southern Italy help to shed light into the formation of these cultural and linguistic identities." "Overall, the study illustrates how both genetic and cultural viewpoints can inform our knowledge of the complex dynamics behind the formation of our Mediterranean heritage, especially in contexts of extensive - both geographically and temporally - admixture," says Davide Pettener, professor of Anthropology from the University of Bologna. "These results," adds Prof. Donata Luiselli, who co-led the project, "will be further developed in future studies integrating data from other disciplines, in particular linguistics, archeology and palaeogenomics, with the study of ancient DNA from archaeological remains."


News Article | May 17, 2017
Site: www.sciencedaily.com

The study -- coordinated by the Human Biodiversity and Population Genomics group at the Department of Biological, Geological and Environmental Sciences (BiGeA) of the University of Bologna and funded by the National Geographic Society -- describes the genetic fingerprints of the Mediterranean people with high-density genomic markers and a wide sample of modern populations from Sicily and Southern Italy. Their genetic profiles were analyzed to reconstruct the combination of ancestry components and the demographic history of the region. As one would expect, populations inhabiting the southeastern shores of Europe are the result of a complex, multi-layered history. One of these layers corresponds to a shared genetic background, extending from Sicily to Cyprus and involving Crete, the Aegean islands and Anatolia. "This shared Mediterranean ancestry possibly traces back to prehistoric times, as the result of multiple migration waves, with peaks during the Neolithic and the Bronze Age," says Stefania Sarno, researcher from the University of Bologna and lead author of the study. Apparently, the ancient Greek expansions (during the Magna Graecia foundation) were only one of the last events in a long history of East-West movements, where the Mediterranean Sea served as a preferential crossroads for the circulation of genes and cultures. A new perspective for the diffusion of Indo-European languages One of the most intriguing layers hidden in the Mediterranean genetic landscape involves an important Bronze Age contribution from a Caucasus (or Caucasus-like) source, accompanied by the virtual absence of the typical "Pontic-Caspian" genetic component from the Asian steppe. The latter is a very characteristic genetic signal well represented in North-Central and Eastern Europe, which previous studies associated with the introduction of Indo-European languages to the continent. "These new genomic results from the Mediterranean open a new chapter for the study of the prehistoric movements behind the diffusion of the most represented language family in Europe. The spread of these languages in the Southern regions, where Indo-European languages like Italian, Greek and Albanian are spoken nowadays, cannot be explained with the major contribution from the steppe alone," adds Chiara Barbieri from the Max Planck Institute for the Science of Human History in Jena. The current genetic study also focuses on more recent historical layers that contributed to the present-day genetic makeup of the populations sampled, in particular in the cases of long-standing, non-Italian-speaking communities in Italy. For example, mainland Greece and Albania seem to have acquired additional genetic contributions during historic times, most likely related to the Slavic migrations in the Balkans. This recent Balkan genetic ancestry is still evident in some ethno-linguistic minorities of Sicily and Southern Italy, such as the Albanian-speaking Arbereshe. The Arbreshe migrated from Albania to Italy at the end of the Middle Ages and experienced geographic and cultural isolation, which played a part in their distinctive genetic composition. A different case study is that of Greek-speaking communities from Southern Italy. The genetic features of these groups are compatible with the antiquity of their settlement and with a high cultural permeability with neighboring populations, combined with drift and effects of geographic isolation, as in the case of Calabrian Greeks. "The study of linguistic and cultural isolates in Italy proved to be important to understand our history and our demography," says Alessio Boattini, geneticist and anthropologist from the University of Bologna. "The cases of the Albanian- and Greek-speaking communities of Southern Italy help to shed light into the formation of these cultural and linguistic identities." "Overall, the study illustrates how both genetic and cultural viewpoints can inform our knowledge of the complex dynamics behind the formation of our Mediterranean heritage, especially in contexts of extensive -- both geographically and temporally -- admixture," says Davide Pettener, professor of Anthropology from the University of Bologna. "These results," adds Prof. Donata Luiselli, who co-led the project, "will be further developed in future studies integrating data from other disciplines, in particular linguistics, archeology and palaeogenomics, with the study of ancient DNA from archaeological remains."


When the first busloads of migrants from Syria and Iraq rolled into Germany 2 years ago, some small towns were overwhelmed. The village of Sumte, population 102, had to take in 750 asylum seekers. Most villagers swung into action, in keeping with Germany’s strong Willkommenskultur, or “welcome culture.” But one self-described neo-Nazi on the district council told The New York Times that by allowing the influx, the German people faced “the destruction of our genetic heritage” and risked becoming “a gray mishmash.” In fact, the German people have no unique genetic heritage to protect. They—and all other Europeans—are already a mishmash, the children of repeated ancient migrations, according to scientists who study ancient human origins. New studies show that almost all indigenous Europeans descend from at least three major migrations in the past 15,000 years, including two from the Middle East. Those migrants swept across Europe, mingled with previous immigrants, and then remixed to create the peoples of today. Using revolutionary new methods to analyze DNA and the isotopes found in bones and teeth, scientists are exposing the tangled roots of peoples around the world, as varied as Germans, ancient Philistines, and Kashmiris. Few of us are actually the direct descendants of the ancient skeletons found in our backyards or historic homelands. Only a handful of groups today, such as Australian Aborigines, have deep bloodlines untainted by mixing with immigrants. “We can falsify this notion that anyone is pure,” says population geneticist Lynn Jorde of the University of Utah in Salt Lake City. Instead, almost all modern humans “have this incredibly complex history of mixing and mating and migration.” Wind back the clock more than a thousand years—a trivial slice of time compared with the 200,000 years or so since our species emerged—and stories of exclusive heritage or territory crumble. “Basically, everybody’s myth is wrong, even the indigenous groups’,” says population geneticist David Reich of Harvard University. Tacitus, the Roman historian, reports that in 9 C.E. a member of the Germanic Cherusci tribe called Arminius led a rebellion against the Romans near the village of Kalkriese in northern Germany. Against all odds, the tribes slaughtered three Roman legions in what became known as the Battle of the Teutoburg Forest. After Tacitus’s account resurfaced in the 15th century, German nationalists resurrected the myth of Arminius, who is often depicted as a blond, muscular young chieftain and known as Hermann. Hailed as the first “German” hero, he was said to have united the Germanic tribes and driven the Romans from their territory. That was considered the start of a period when fearsome Germanic tribes such as the Vandals swept around Europe, wresting territory from Romans and others. In the 20th century, the Nazis added their own dark spin to that origin story, citing Arminius as part of an ancient pedigree of a “master race” from Germany and northern Europe that they called Aryans. They used their view of prehistory and archaeology to justify claims to the tribes’ ancient homelands in Poland and Austria. Scholars agree that there was indeed a real battle that sent shock waves through the Roman Empire, which then stretched from the island of Britain to Egypt. But much of the rest of Arminius’s story is myth: The Romans persisted deep in Germania until at least the third century C.E., as shown by the recent discovery of a third-century Roman battlefield in Harzhorn, Germany. And Arminius by no means united the more than 50 Germanic tribes of the time. He persuaded five tribes to join him in battle, but members of his own tribe soon killed him. Moreover, Arminius and his kin were not pure “Aryan,” if that term means a person whose ancestors lived solely in what is now Germany or Scandinavia. The Cherusci tribe, like all Europeans of their day and later, were themselves composites, built from serial migrations into the heart of Europe and then repeatedly remixed. “The whole concept of an ethnic German … it’s ludicrous when you look at the longue durée [long time] scale,” says archaeologist Aren Maeir of Bar-Ilan University in Ramat Gan, Israel. After World War II, many scholars recoiled from studying migrations, in reaction to the Nazi misuse of history and archaeology. The Nazis had invoked migrations of “foreign” groups to German territory to justify genocide. “The whole field of migration studies was ideologically tainted,” says archaeologist Kristian Kristiansen of the University of Gothenburg in Sweden. Some researchers also resisted the idea that migration helped spread key innovations such as farming, partly because that might imply that certain groups were superior. Nor did researchers have a reliable method to trace prehistoric migrations. “Most of the archaeological evidence for movement is based on artifacts, but artifacts can be stolen or copied, so they are not a real good proxy for actual human movement,” says archaeologist Doug Price of the University of Wisconsin in Madison, who tracks ancient migration by analyzing isotopes. “When I started doing this in 1990, I thought people were very sedentary and didn’t move around much.” Today, however, new methods yield more definitive evidence of migration, sparking an explosion of studies. The isotopes Price and others study are specific to local water and food and thus can reveal where people grew up and whether they later migrated. DNA from ancient skeletons and living people offers the “gold standard” in proving who was related to whom. The new data confirm that humans have always had wanderlust, plus a yen to mix with all manner of strangers. After the first Homo sapiens arose in Africa, several bands walked out of the continent about 60,000 years ago and into the arms of Neandertals and other archaic humans. Today, almost all humans outside Africa carry traces of archaic DNA. That was just one of many episodes of migration and mixing. The first Europeans came from Africa via the Middle East and settled there about 43,000 years ago. But some of those pioneers, such as a 40,000-year-old individual from Romania, have little connection to today’s Europeans, Reich says. His team studied DNA from 51 Europeans and Asians who lived 7000 to 45,000 years ago. They found that most of the DNA in living Europeans originated in three major migrations, starting with hunter-gatherers who came from the Middle East as the glaciers retreated 19,000 to 14,000 years ago. In a second migration about 9000 years ago, farmers from northwestern Anatolia, in what is now Greece and Turkey, moved in. That massive wave of farmers washed across the continent. Ancient DNA records their arrival in Germany, where they are linked with the Linear Pottery culture, 6900 to 7500 years ago. A 7000-year-old woman from Stuttgart, Germany, for example, has the farmers’ genetic signatures, setting her apart from eight hunter-gatherers who lived just 1000 years earlier in Luxembourg and Sweden. Among people living today, Sardinians retain the most DNA from those early farmers, whose genes suggest that they had brown eyes and dark hair. The farmers moved in family groups and stuck to themselves awhile before mixing with local hunter-gatherers, according to a study in 2015 that used ancient DNA to calculate the ratio of men to women in the farming groups. That’s a stark contrast to the third major migration, which began about 5000 years ago when herders swept in from the steppe north of the Black Sea in what is now Russia. Those Yamnaya pastoralists herded cattle and sheep, and some rode newly domesticated horses, says archaeologist David Anthony of Hartwick College in Oneonta, New York. In the journal Antiquity last month, Kristiansen and paleogeneticist Eske Willerslev at the University of Copenhagen reported that the sex ratios of the earliest Yamnaya burials in central Europe suggest that the new arrivals were mostly men. Arriving with few women, those tall strangers were apparently eager to woo or abduct the local farmers’ daughters. Not long after the Yamnaya invasion, their skeletons were buried with those of women who had lived on farms as children, according to the strontium and nitrogen isotopes in their bones, says Price, who analyzed them. The unions between the Yamnaya and the descendants of Anatolian farmers catalyzed the creation of the famous Corded Ware culture, known for its distinctive pottery impressed with cordlike patterns, Kristiansen says. According to DNA analysis, those people may have inherited Yamnaya genes that made them taller; they may also have had a then-rare mutation that enabled them to digest lactose in milk, which quickly spread. It was a winning combination. The Corded Ware people had many offspring who spread rapidly across Europe. They were among the ancestors of the Bell Beaker culture of central Europe, known by the vessels they used to drink wine, according to a study by Kristiansen and Reich published this month. “This big wave of Yamnaya migration washed all the way to the shores of Ireland,” says population geneticist Dan Bradley of Trinity College in Dublin. Bell Beaker pots and DNA appeared about 4000 years ago in burials on Rathlin Island, off the coast of Northern Ireland, his group reported this year. This new picture means that the Hermann of lore was himself a composite of post–ice age hunter-gatherers, Anatolian farmers, and Yamnaya herders. So are most other Europeans—including the ancient Romans whose empire Arminius fought. The three-part European mixture varies across the continent, with different ratios of each migration and trace amounts of other lineages. But those quirks rarely match the tales people tell about their ancestry. For example, the Basques of northern Spain, who have a distinct language, have long thought themselves a people apart. But last year, population geneticist Mattias Jakobsson of Uppsala University in Sweden reported that the DNA of modern Basques is most like that of the ancient farmers who populated northern Spain before the Yamnaya migration. In other words, Basques are part of the usual European mix, although they carry less Yamnaya DNA than other Europeans. Farther north, the Irish Book of Invasions, written by an anonymous author in the 11th century, recounts that the “Sons of Míl Espáine … after many wanderings in Scythia and Egypt” eventually reached Spain and Ireland, creating a modern Irish people distinct from the British—and linked to the Spanish. That telling resonates with a later yarn about ships from the Spanish Armada, wrecked on the shores of Ireland and the Scottish Orkney Islands in 1588, Bradley says: “Good-looking, dark-haired Spaniards washed ashore” and had children with Gaelic and Orkney Islands women, creating a strain of Black Irish with dark hair, eyes, and skin. Although it’s a great story, Bradley says, it “just didn’t happen.” In two studies, researchers have found only “a very small ancient Spanish contribution” to British and Irish DNA, says human geneticist Walter Bodmer of the University of Oxford in the United Kingdom, co-leader of a landmark 2015 study of British genetics. The Irish also cherish another origin story, of the Celtic roots they are said to share with the Scots and Welsh. In the Celtic Revival of the 19th and 20th centuries, writers such as William Butler Yeats drew from stories in the Book of Invasions and medieval texts. Those writings described a migration of Gaels, or groups of Celts from the mainland who clung to their identity in the face of later waves of Roman, Germanic, and Nordic peoples. But try as they might, researchers so far haven’t found anyone, living or dead, with a distinct Celtic genome. The ancient Celts got their name from Greeks who used “Celt” as a label for barbarian outsiders—the diverse Celtic-speaking tribes who, starting in the late Bronze Age, occupied territory from Portugal to Turkey. “It’s a hard question who the Celts are,” says population geneticist Stephan Schiffels of the Max Planck Institute for the Science of Human History in Jena, Germany. Bodmer’s team traced the ancestry of 2039 people whose families have lived in the same parts of Scotland, Northern Ireland, and Wales since the 19th century. These people form at least nine genetic and geographic clusters, showing that after their ancestors arrived in those regions, they put down roots and married their neighbors. But the clusters themselves are of diverse origin, with close ties to people now in Germany, Belgium, and France. “‘Celtic’ is a cultural definition,” Bodmer says. “It has nothing to do with hordes of people coming from somewhere else and replacing people.” English myths fare no better. The Anglo-Saxon Chronicle recounts that in 449 C.E., two Germanic tribespeople, Hengist and Horsa, sailed from what is now the Netherlands to southeast England, starting a fierce conflict. As more Angles, Saxons, and Jutes arrived, violence broke out with the local Britons and ended in “rivers of blood,” according to accounts by medieval monks. Scholars have debated just how bloody that invasion was, and whether it was a mass migration or a small delegation of elite kings and their warriors. An answer came in 2016 from a study of the ancient DNA of Anglo-Saxons and indigenous Britons, who were buried side by side in the fifth and sixth centuries in a cemetery near Cambridge, U.K. They lived and died together and even interbred, as shown by one person who had a mix of DNA from both Britons and Anglo-Saxons, and a genetic Briton who was buried with a large cruciform Anglo-Saxon brooch. Although the stories stress violence, the groups “were mixing very quickly,” says Duncan Sayer, an archaeologist at the University of Central Lancashire in Preston, U.K., who co-wrote the study. The team went on to show that 25% to 40% of the ancestry of modern Britons is Anglo-Saxon. Even people in Wales and Scotland—thought to be Celtic strongholds—get about 30% of their DNA from Anglo-Saxons, says co-author Chris Tyler-Smith of the Wellcome Trust’s Sanger Institute in Hinxton, U.K. The boom in studies of migration is centered on Europe, where access to ancient remains is relatively easy and cold climates can help preserve DNA. But geneticists are beginning to probe the makeup of ancient people elsewhere. For example, findings from recent excavations in Israel are close to solving a long-standing mystery from the Bible: the identity of the ancient Philistines. In biblical texts, those “uncircumcised” people are known as the bitter enemies of the Israelites; the name “Philistine” is still a slur in English. They’re said to have lived in Canaan, between present-day Tel Aviv and Gaza in Israel. They ate pork, battled Samson’s armies, and stole the Ark of the Covenant. Goliath, whom David slew with a sling, was a Philistine. But after Old Testament times, the group disappears from both scripture and historical accounts. To find the Philistines’ origins, researchers have studied artifacts and remains from ancient Philistine cities in Israel. The evidence, including isotopic analysis, shows that the Philistines were a motley crew of immigrants, possibly pirates, who hailed from many ports, bringing pigs from Europe and donkeys in caravans from Egypt. “The Philistines are an entangled culture from western Anatolia, Cyprus, Greece, the Balkans, you name it,” says Maeir, who has directed excavations at the Philistine city of Gath for 2 decades. Maeir says he thinks that the Philistines soon intermarried with people already living in Canaan instead of going extinct. If so, the loathsome Philistines are part of the ancestral stock for both Palestinian Muslims and Israeli Jews. Those groups, so full of enmity today, are genetically closely related, according to a study in 2000 of the paternally inherited Y chromosomes of 119 Ashkenazi and Sephardic Jews and 143 Israeli and Palestinian Arabs. Seventy percent of the Jewish men and half of the Arab men inherited their Y chromosomes from the same set of paternal ancestors who lived in the Middle East within the last few thousand years. As techniques for probing ethnic origins spread, nearly every week brings a new paper testing and often falsifying lore about one ancient culture or another. The Kashmiri of northern India do not seem to be related to Alexander the Great or the lost tribes of Israel. Parsis in Iran and India are not solely of ancient Iranian heritage, having mixed with local Indian women, although Parsi priests do descend chiefly from just two men. “Ethnic groups in the past and present create an ‘imagined past’ of the longtime and ‘pure’ origins of their group,” Maeir says. But that created past often has “little true relation to the historical processes” that actually created the group, he says. So far, the origin stories that appear to hew most closely to reality belong to indigenous peoples around the world. For example, the Tlingit and Tsimshian tribes of British Columbia in Canada and Alaska claim to have lived along the west coast of North America from “time immemorial.” Living tribespeople do descend in part from three ancient Native Americans who lived in the region 2500 to 6000 years ago, according to DNA analyses published last month. Even so, most modern Native Americans are not directly related to the ancient people who lived in the same areas because their offspring moved, were displaced, or went extinct over the millennia, Reich says. In Australia, aboriginal stories recall even longer connections to their lands, even seeming to refer to times when sea levels rose and fell more than 15,000 years ago. Those claims are among the few that genome studies support. DNA evidence puts aboriginal ancestors on the continent 40,000 to 60,000 years ago. Once the first Australians arrived, they settled in three regions and remained in those discrete homelands for tens of thousands of years, a DNA study published in March suggests. But the Aborigines are rare among the peoples of Earth, where migrations have been the norm. Almost always, Reich says, “the idea that the ancestors of any one population have lived in the same place for tens of thousands of years with no substantial immigration is wrong.” Back in Sumte in the fall of 2015, the 750 refugees from Syria arrived on schedule. The adults mostly kept to themselves, learning German and taking occasional construction jobs. But their children sang “O Tannenbaum” in a local church at Christmas and their teens ventured out often, seeking cellphone signals in the quiet town. In the following months, almost all the refugees dispersed to larger towns throughout Germany. In time, some of the young immigrants will contribute their DNA to the next generation of Germans, re-enacting on a small scale the process of migration and assimilation that once played out repeatedly on this same land—and far beyond.


News Article | May 15, 2017
Site: www.sciencemag.org

When the first busloads of migrants from Syria and Iraq rolled into Germany 2 years ago, some small towns were overwhelmed. The village of Sumte, population 102, had to take in 750 asylum seekers. Most villagers swung into action, in keeping with Germany’s strong Willkommenskultur, or “welcome culture.” But one self-described neo-Nazi on the district council told The New York Times that by allowing the influx, the German people faced “the destruction of our genetic heritage” and risked becoming “a gray mishmash.” In fact, the German people have no unique genetic heritage to protect. They—and all other Europeans—are already a mishmash, the children of repeated ancient migrations, according to scientists who study ancient human origins. New studies show that almost all indigenous Europeans descend from at least three major migrations in the past 15,000 years, including two from the Middle East. Those migrants swept across Europe, mingled with previous immigrants, and then remixed to create the peoples of today. Using revolutionary new methods to analyze DNA and the isotopes found in bones and teeth, scientists are exposing the tangled roots of peoples around the world, as varied as Germans, ancient Philistines, and Kashmiris. Few of us are actually the direct descendants of the ancient skeletons found in our backyards or historic homelands. Only a handful of groups today, such as Australian Aborigines, have deep bloodlines untainted by mixing with immigrants. “We can falsify this notion that anyone is pure,” says population geneticist Lynn Jorde of the University of Utah in Salt Lake City. Instead, almost all modern humans “have this incredibly complex history of mixing and mating and migration.” Wind back the clock more than a thousand years—a trivial slice of time compared with the 200,000 years or so since our species emerged—and stories of exclusive heritage or territory crumble. “Basically, everybody’s myth is wrong, even the indigenous groups’,” says population geneticist David Reich of Harvard University. Tacitus, the Roman historian, reports that in 9 C.E. a member of the Germanic Cherusci tribe called Arminius led a rebellion against the Romans near the village of Kalkriese in northern Germany. Against all odds, the tribes slaughtered three Roman legions in what became known as the Battle of the Teutoburg Forest. After Tacitus’s account resurfaced in the 15th century, German nationalists resurrected the myth of Arminius, who is often depicted as a blond, muscular young chieftain and known as Hermann. Hailed as the first “German” hero, he was said to have united the Germanic tribes and driven the Romans from their territory. That was considered the start of a period when fearsome Germanic tribes such as the Vandals swept around Europe, wresting territory from Romans and others. In the 20th century, the Nazis added their own dark spin to that origin story, citing Arminius as part of an ancient pedigree of a “master race” from Germany and northern Europe that they called Aryans. They used their view of prehistory and archaeology to justify claims to the tribes’ ancient homelands in Poland and Austria. Scholars agree that there was indeed a real battle that sent shock waves through the Roman Empire, which then stretched from the island of Britain to Egypt. But much of the rest of Arminius’s story is myth: The Romans persisted deep in Germania until at least the third century C.E., as shown by the recent discovery of a third-century Roman battlefield in Harzhorn, Germany. And Arminius by no means united the more than 50 Germanic tribes of the time. He persuaded five tribes to join him in battle, but members of his own tribe soon killed him. Moreover, Arminius and his kin were not pure “Aryan,” if that term means a person whose ancestors lived solely in what is now Germany or Scandinavia. The Cherusci tribe, like all Europeans of their day and later, were themselves composites, built from serial migrations into the heart of Europe and then repeatedly remixed. “The whole concept of an ethnic German … it’s ludicrous when you look at the longue durée [long time] scale,” says archaeologist Aren Maeir of Bar-Ilan University in Ramat Gan, Israel. After World War II, many scholars recoiled from studying migrations, in reaction to the Nazi misuse of history and archaeology. The Nazis had invoked migrations of “foreign” groups to German territory to justify genocide. “The whole field of migration studies was ideologically tainted,” says archaeologist Kristian Kristiansen of the University of Gothenburg in Sweden. Some researchers also resisted the idea that migration helped spread key innovations such as farming, partly because that might imply that certain groups were superior. Nor did researchers have a reliable method to trace prehistoric migrations. “Most of the archaeological evidence for movement is based on artifacts, but artifacts can be stolen or copied, so they are not a real good proxy for actual human movement,” says archaeologist Doug Price of the University of Wisconsin in Madison, who tracks ancient migration by analyzing isotopes. “When I started doing this in 1990, I thought people were very sedentary and didn’t move around much.” Today, however, new methods yield more definitive evidence of migration, sparking an explosion of studies. The isotopes Price and others study are specific to local water and food and thus can reveal where people grew up and whether they later migrated. DNA from ancient skeletons and living people offers the “gold standard” in proving who was related to whom. The new data confirm that humans have always had wanderlust, plus a yen to mix with all manner of strangers. After the first Homo sapiens arose in Africa, several bands walked out of the continent about 60,000 years ago and into the arms of Neandertals and other archaic humans. Today, almost all humans outside Africa carry traces of archaic DNA. That was just one of many episodes of migration and mixing. The first Europeans came from Africa via the Middle East and settled there about 43,000 years ago. But some of those pioneers, such as a 40,000-year-old individual from Romania, have little connection to today’s Europeans, Reich says. His team studied DNA from 51 Europeans and Asians who lived 7000 to 45,000 years ago. They found that most of the DNA in living Europeans originated in three major migrations, starting with hunter-gatherers who came from the Middle East as the glaciers retreated 19,000 to 14,000 years ago. In a second migration about 9000 years ago, farmers from northwestern Anatolia, in what is now Greece and Turkey, moved in. That massive wave of farmers washed across the continent. Ancient DNA records their arrival in Germany, where they are linked with the Linear Pottery culture, 6900 to 7500 years ago. A 7000-year-old woman from Stuttgart, Germany, for example, has the farmers’ genetic signatures, setting her apart from eight hunter-gatherers who lived just 1000 years earlier in Luxembourg and Sweden. Among people living today, Sardinians retain the most DNA from those early farmers, whose genes suggest that they had brown eyes and dark hair. The farmers moved in family groups and stuck to themselves awhile before mixing with local hunter-gatherers, according to a study in 2015 that used ancient DNA to calculate the ratio of men to women in the farming groups. That’s a stark contrast to the third major migration, which began about 5000 years ago when herders swept in from the steppe north of the Black Sea in what is now Russia. Those Yamnaya pastoralists herded cattle and sheep, and some rode newly domesticated horses, says archaeologist David Anthony of Hartwick College in Oneonta, New York. In the journal Antiquity last month, Kristiansen and paleogeneticist Eske Willerslev at the University of Copenhagen reported that the sex ratios of the earliest Yamnaya burials in central Europe suggest that the new arrivals were mostly men. Arriving with few women, those tall strangers were apparently eager to woo or abduct the local farmers’ daughters. Not long after the Yamnaya invasion, their skeletons were buried with those of women who had lived on farms as children, according to the strontium and nitrogen isotopes in their bones, says Price, who analyzed them. The unions between the Yamnaya and the descendants of Anatolian farmers catalyzed the creation of the famous Corded Ware culture, known for its distinctive pottery impressed with cordlike patterns, Kristiansen says. According to DNA analysis, those people may have inherited Yamnaya genes that made them taller; they may also have had a then-rare mutation that enabled them to digest lactose in milk, which quickly spread. It was a winning combination. The Corded Ware people had many offspring who spread rapidly across Europe. They were among the ancestors of the Bell Beaker culture of central Europe, known by the vessels they used to drink wine, according to a study by Kristiansen and Reich published this month. “This big wave of Yamnaya migration washed all the way to the shores of Ireland,” says population geneticist Dan Bradley of Trinity College in Dublin. Bell Beaker pots and DNA appeared about 4000 years ago in burials on Rathlin Island, off the coast of Northern Ireland, his group reported this year. This new picture means that the Hermann of lore was himself a composite of post–ice age hunter-gatherers, Anatolian farmers, and Yamnaya herders. So are most other Europeans—including the ancient Romans whose empire Arminius fought. The three-part European mixture varies across the continent, with different ratios of each migration and trace amounts of other lineages. But those quirks rarely match the tales people tell about their ancestry. For example, the Basques of northern Spain, who have a distinct language, have long thought themselves a people apart. But last year, population geneticist Mattias Jakobsson of Uppsala University in Sweden reported that the DNA of modern Basques is most like that of the ancient farmers who populated northern Spain before the Yamnaya migration. In other words, Basques are part of the usual European mix, although they carry less Yamnaya DNA than other Europeans. Farther north, the Irish Book of Invasions, written by an anonymous author in the 11th century, recounts that the “Sons of Míl Espáine … after many wanderings in Scythia and Egypt” eventually reached Spain and Ireland, creating a modern Irish people distinct from the British—and linked to the Spanish. That telling resonates with a later yarn about ships from the Spanish Armada, wrecked on the shores of Ireland and the Scottish Orkney Islands in 1588, Bradley says: “Good-looking, dark-haired Spaniards washed ashore” and had children with Gaelic and Orkney Islands women, creating a strain of Black Irish with dark hair, eyes, and skin. Although it’s a great story, Bradley says, it “just didn’t happen.” In two studies, researchers have found only “a very small ancient Spanish contribution” to British and Irish DNA, says human geneticist Walter Bodmer of the University of Oxford in the United Kingdom, co-leader of a landmark 2015 study of British genetics. The Irish also cherish another origin story, of the Celtic roots they are said to share with the Scots and Welsh. In the Celtic Revival of the 19th and 20th centuries, writers such as William Butler Yeats drew from stories in the Book of Invasions and medieval texts. Those writings described a migration of Gaels, or groups of Celts from the mainland who clung to their identity in the face of later waves of Roman, Germanic, and Nordic peoples. But try as they might, researchers so far haven’t found anyone, living or dead, with a distinct Celtic genome. The ancient Celts got their name from Greeks who used “Celt” as a label for barbarian outsiders—the diverse Celtic-speaking tribes who, starting in the late Bronze Age, occupied territory from Portugal to Turkey. “It’s a hard question who the Celts are,” says population geneticist Stephan Schiffels of the Max Planck Institute for the Science of Human History in Jena, Germany. Bodmer’s team traced the ancestry of 2039 people whose families have lived in the same parts of Scotland, Northern Ireland, and Wales since the 19th century. These people form at least nine genetic and geographic clusters, showing that after their ancestors arrived in those regions, they put down roots and married their neighbors. But the clusters themselves are of diverse origin, with close ties to people now in Germany, Belgium, and France. “‘Celtic’ is a cultural definition,” Bodmer says. “It has nothing to do with hordes of people coming from somewhere else and replacing people.” English myths fare no better. The Anglo-Saxon Chronicle recounts that in 449 C.E., two Germanic tribespeople, Hengist and Horsa, sailed from what is now the Netherlands to southeast England, starting a fierce conflict. As more Angles, Saxons, and Jutes arrived, violence broke out with the local Britons and ended in “rivers of blood,” according to accounts by medieval monks. Scholars have debated just how bloody that invasion was, and whether it was a mass migration or a small delegation of elite kings and their warriors. An answer came in 2016 from a study of the ancient DNA of Anglo-Saxons and indigenous Britons, who were buried side by side in the fifth and sixth centuries in a cemetery near Cambridge, U.K. They lived and died together and even interbred, as shown by one person who had a mix of DNA from both Britons and Anglo-Saxons, and a genetic Briton who was buried with a large cruciform Anglo-Saxon brooch. Although the stories stress violence, the groups “were mixing very quickly,” says Duncan Sayer, an archaeologist at the University of Central Lancashire in Preston, U.K., who co-wrote the study. The team went on to show that 25% to 40% of the ancestry of modern Britons is Anglo-Saxon. Even people in Wales and Scotland—thought to be Celtic strongholds—get about 30% of their DNA from Anglo-Saxons, says co-author Chris Tyler-Smith of the Wellcome Trust’s Sanger Institute in Hinxton, U.K. The boom in studies of migration is centered on Europe, where access to ancient remains is relatively easy and cold climates can help preserve DNA. But geneticists are beginning to probe the makeup of ancient people elsewhere. For example, findings from recent excavations in Israel are close to solving a long-standing mystery from the Bible: the identity of the ancient Philistines. In biblical texts, those “uncircumcised” people are known as the bitter enemies of the Israelites; the name “Philistine” is still a slur in English. They’re said to have lived in Canaan, between present-day Tel Aviv and Gaza in Israel. They ate pork, battled Samson’s armies, and stole the Ark of the Covenant. Goliath, whom David slew with a sling, was a Philistine. But after Old Testament times, the group disappears from both scripture and historical accounts. To find the Philistines’ origins, researchers have studied artifacts and remains from ancient Philistine cities in Israel. The evidence, including isotopic analysis, shows that the Philistines were a motley crew of immigrants, possibly pirates, who hailed from many ports, bringing pigs from Europe and donkeys in caravans from Egypt. “The Philistines are an entangled culture from western Anatolia, Cyprus, Greece, the Balkans, you name it,” says Maeir, who has directed excavations at the Philistine city of Gath for 2 decades. Maeir says he thinks that the Philistines soon intermarried with people already living in Canaan instead of going extinct. If so, the loathsome Philistines are part of the ancestral stock for both Palestinian Muslims and Israeli Jews. Those groups, so full of enmity today, are genetically closely related, according to a study in 2000 of the paternally inherited Y chromosomes of 119 Ashkenazi and Sephardic Jews and 143 Israeli and Palestinian Arabs. Seventy percent of the Jewish men and half of the Arab men inherited their Y chromosomes from the same set of paternal ancestors who lived in the Middle East within the last few thousand years. As techniques for probing ethnic origins spread, nearly every week brings a new paper testing and often falsifying lore about one ancient culture or another. The Kashmiri of northern India do not seem to be related to Alexander the Great or the lost tribes of Israel. Parsis in Iran and India are not solely of ancient Iranian heritage, having mixed with local Indian women, although Parsi priests do descend chiefly from just two men. “Ethnic groups in the past and present create an ‘imagined past’ of the longtime and ‘pure’ origins of their group,” Maeir says. But that created past often has “little true relation to the historical processes” that actually created the group, he says. So far, the origin stories that appear to hew most closely to reality belong to indigenous peoples around the world. For example, the Tlingit and Tsimshian tribes of British Columbia in Canada and Alaska claim to have lived along the west coast of North America from “time immemorial.” Living tribespeople do descend in part from three ancient Native Americans who lived in the region 2500 to 6000 years ago, according to DNA analyses published last month. Even so, most modern Native Americans are not directly related to the ancient people who lived in the same areas because their offspring moved, were displaced, or went extinct over the millennia, Reich says. In Australia, aboriginal stories recall even longer connections to their lands, even seeming to refer to times when sea levels rose and fell more than 15,000 years ago. Those claims are among the few that genome studies support. DNA evidence puts aboriginal ancestors on the continent 40,000 to 60,000 years ago. Once the first Australians arrived, they settled in three regions and remained in those discrete homelands for tens of thousands of years, a DNA study published in March suggests. But the Aborigines are rare among the peoples of Earth, where migrations have been the norm. Almost always, Reich says, “the idea that the ancestors of any one population have lived in the same place for tens of thousands of years with no substantial immigration is wrong.” Back in Sumte in the fall of 2015, the 750 refugees from Syria arrived on schedule. The adults mostly kept to themselves, learning German and taking occasional construction jobs. But their children sang “O Tannenbaum” in a local church at Christmas and their teens ventured out often, seeking cellphone signals in the quiet town. In the following months, almost all the refugees dispersed to larger towns throughout Germany. In time, some of the young immigrants will contribute their DNA to the next generation of Germans, re-enacting on a small scale the process of migration and assimilation that once played out repeatedly on this same land—and far beyond.


News Article | November 2, 2016
Site: www.csmonitor.com

Tools, pigments, and other artifacts found in an ancient rock shelter could place humans in the Australian interior 10,000 years earlier than previously thought, say scientists. A sharpened bone point, dated to 40-38 thousand years old and now the oldest bone tool yet found in Australia. Likely to be ground from the cylindrical portion of the proximal end of a macropod fibula similar in size to Petrogale xanthopus, Yellow Footed Rock Wallaby. Scientists often look at the peopling of Australia as a sort of benchmark for when modern humans were spreading out of Africa and establishing populations across the globe. But the details of that story are still hotly debated. Estimates of when the first people arrived on the continent range from 45,000 to 60,000 years ago and researchers debate where these first Australians went next and how they lived. But an artifact-filled ancient rock shelter in the southern interior of Australia may help archaeologists clarify that story. Radiocarbon dating suggests the cliff-side shelter, called Warratyi, may have first been inhabited some 49,000 years ago, according to a paper published Wednesday in the journal Nature. And, as the paper's authors assert humans first arrived in northwest Australia some 50,000 years ago, that means humans may have hustled well over 1,000 miles over the course of just about a millennium. This also would place humans in the continent's interior nearly 10,000 years earlier than other archaeological evidence has suggested, study lead author Giles Hamm of La Trobe University in Melbourne said in a Nature podcast. Previously researchers thought humans began spreading along the then-rainforested coasts of Australia upon arrival, populating the less lush interior no earlier than 40,000 years ago. But, as the Warratyi shelter is over 100 miles inland, that may not have been the case. "It's potentially a landmark publication," Michael Petraglia, an anthropologist at the Max Planck Institute for the Science of Human History in Germany who was not part of the study, tells The Christian Science Monitor in a phone interview. "It's a very important new site and a very important new excavation," he says of the new study. "It's chock full of new information." But Dr. Petraglia urges caution. "While I welcome this new excavation in an important area," he says, "It's only about three feet of sediment that represents more than 40,000 years of history." And because the site is "pretty low-resolution" and it's just one site, Petraglia says more sites will help put these new artifacts into context. Still, Petraglia says the complex tools found at the site suggest that these first Australians were highly innovative and culturally advanced when they first arrived. Among the oldest artifacts at the site, the researchers found red ochre on some tools suggesting the earliest known use of a pigment used today in cultural body adornment. The team also found tools made of bone that they dated to be between 38,000 and 40,000 years old, and tools used just a few thousand years later that were made by attaching multiple pieces, like a sharp stone to a shaft, for example. "That's fantastic because some of the theories out there have been that they were sort of depauperate in their knowledge and that [the first] Australian aborigines were only making simple stone tools, for example, and very little else," Petraglia says. And "this is showing that people were already not only technologically advanced, but symbolically advanced, cognitively advanced." In many regions, large animals began going extinct when humans arrived on the scene. But scientists have yet to agree whether humans had a hand in megafaunal extinctions or if, as the other popular theory suggests, climate change killed them off. "Sites with evidence of megafaunal hunting are relatively common on other continents, such as North America, but a definitive case has been out of reach in Australia," Brian Codding, an anthropologist at the University of Utah who was not part of the study, tells the Monitor in an email. But the Warratyi shelter could change that. Among the prehistoric tools, Dr. Hamm and his colleagues found a bone belonging to a Diprotodon optatum, a massive extinct herbivore thought to be the largest marsupial to have ever existed. It's unlikely this humongous animal clambered up the rocks itself, so the researchers think humans must have carried the bone up some 46,000 years ago. It's unclear whether humans hunted the animal thought to weigh more than 6,000 pounds. But the researchers also found fragments of eggshells from the extinct, large flightless bird Genyornis newtoni among the oldest artifacts at the site. And they think some of those shells were burnt, suggesting the first Australians were already cooking up the birds' eggs. "Many have argued that humans played no role in the extinction of Australia’s megafauna," Dr. Codding says. But based on the artifacts found associated with the animals' remains, "the authors of this paper suggest otherwise." "If this finding is supported by further investigations," he says, "this will be a game-changer for Australian prehistory."


News Article | February 23, 2017
Site: www.techtimes.com

Salmonella infections could have been one of the contributing factors that resulted in a large number of deaths among the Aztecs that lived in Mexico before the Spaniards arrived. The die-off could have caused the fall of the Aztec empire. The native population of the Aztecs is believed to number about 25 million when the Spanish explorers arrived in 1519. One hundred years later, however, the number of natives in the New World decreased to just 1 million. Earlier studies suggested that the drop in the local population occurred mostly because of diseases that were brought by the European explorers, but until now no disease has been conclusively identified as responsible for the decline of the Aztec population. In two new studies, researchers have suggested that a strain of salmonella could be behind the dramatic population drop. Foodborne illnesses are often attributed to salmonella. Fears over salmonella contamination that could potentially cause illness often prompt recalls of food products but only a few of the salmonella serotypes are responsible for most foodborne illnesses. The salmonella strain known as Salmonella enterica Paratyphi C is known to cause enteric fever, a bacterial infection with symptoms similar to those of typhoid fever and kills between 10 to 15 percent of those infected. Researchers now think that this strain of salmonella could be what caused the illness that killed millions of natives in Mexico. Study researcher Ashild Vagene, from the Max Planck Institute for the Science of Human History, and colleagues sequenced the DNA taken from the teeth of Aztecs that died during the cocoliztli epidemic that ran between 1545 and 1576. The epidemic killed about 80 percent of the population. Several diseases including smallpox, measles, and typhus have been blamed for the outbreak but no solid evidence has yet been established to confirm any of the hypotheses. Using the metagenomic tool MALT to find traces of ancient pathogen, the researchers reported finding S. enterica in several of the samples they collected and analyzed. "We propose that S. Paratyphi C contributed to the population decline during the 1545 cocoliztli outbreak in Mexico," the researchers reported in their study. Researchers of the second study studied the remains of a woman who died in Norway 300 years before the cocoliztli epidemic occurred and found evidence of S. enterica. The discovery suggests that the salmonella strain present in the New World victims may have originated from Europe, albeit it was not clear how closely the strains matched. "We recovered a draft Paratyphi C genome from the 800-year-old skeleton of a young woman in Trondheim, Norway, who likely died of enteric fever," study researcher Zhemin Zhou, from University of Warwick, and colleagues wrote. Both studies, which have not yet been peer-reviewed, did not provide conclusive evidence that salmonella was the disease that caused the death of the Aztecs, however. The evidence though hints that it likely made a contribution to the eventual collapse of the Aztec empire. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | February 22, 2017
Site: www.nature.com

One of the worst epidemics in human history, a sixteenth-century pestilence that devastated Mexico’s native population, may have been caused by a deadly form of salmonella from Europe, a pair of studies suggest. In one study, researchers say they have recovered DNA of the stomach bacterium from burials in Mexico linked to a 1540s epidemic that killed up to 80% of the country's native inhabitants. The team reports its findings in a preprint posted on the bioRxiv server on 8 February1. This is potentially the first genetic evidence of the pathogen that caused the massive decline in native populations after European colonization, says Hannes Schroeder, an ancient-DNA researcher at the Natural History Museum of Denmark in Copenhagen who was not involved in the work. “It’s a super-cool study.” In 1519, when forces led by Spanish conquistador Hernando Cortés arrived in Mexico, the native population was estimated at about 25 million. A century later, after a Spanish victory and a series of epidemics, numbers had plunged to around 1 million. The largest of these disease outbreaks were known as cocoliztli (from the word for ‘pestilence’ in Nahuatl, the Aztec language). Two major cocoliztli, beginning in 1545 and 1576, killed an estimated 7 million to 18 million people living in Mexico’s highland regions. “In the cities and large towns, big ditches were dug, and from morning to sunset the priests did nothing else but carry the dead bodies and throw them into the ditches,” noted a Franciscan historian who witnessed the 1576 outbreak. There has been little consensus on the cause of cocoliztli — although measles, smallpox and typhus have all been mooted. In 2002, researchers at the National Autonomous University of Mexico (UNAM) in Mexico City proposed that a viral haemorrhagic fever, exacerbated by a catastrophic drought, was behind the carnage2. They compared the magnitude of the 1545 outbreak to that of the Black Death in fourteenth-century Europe. In an attempt to settle the question, a team led by evolutionary geneticist Johannes Krause at the Max Planck Institute for the Science of Human History in Jena, Germany, extracted and sequenced DNA from the teeth of 29 people buried in the Oaxacan highlands of southern Mexico. All but five were linked to a cocoliztli that researchers think ran from 1545 to 1550. Ancient bacterial DNA recovered from several of the people matched that of Salmonella, based on comparisons with a database of more than 2,700 modern bacterial genomes. Further sequencing of short, damaged DNA fragments from the remains allowed the team to reconstruct two genomes of a Salmonella enterica strain known as Paratyphi C. Today, this bacterium causes enteric fever, a typhus-like illness, that occurs mostly in developing countries. If left untreated, it kills 10–15% of infected people. It’s perfectly reasonable that the bacterium could have caused this epidemic, says Schroeder. “They make a really good case.” But María Ávila-Arcos, an evolutionary geneticist at UNAM, isn't convinced. She notes that some people suggest that a virus caused the cocoliztli, and that wouldn't have been picked up by the team’s method. Krause and his colleagues’ proposal is helped by another study posted on bioRxiv last week, which raises the possibility that Salmonella Paratyphi C arrived in Mexico from Europe3. A team led by Mark Achtman, a microbiologist at the University of Warwick in Coventry, UK, collected and sequenced the genome of the bacterial strain from the remains of a young woman buried around 1200 in a cemetery in Trondheim, Norway. It is the earliest evidence for the now-rare Salmonella strain, and proof that it was circulating in Europe, according to the study. (Both teams declined to comment on their research because their papers have been submitted to a peer-reviewed journal.) “Really, what we’d like to do is look at both strains together,” says Hendrik Poinar, an evolutionary biologist at McMaster University in Hamilton, Canada. And if more ancient genomes can be collected from Europe and the Americas, it should be possible to find out more conclusively whether deadly pathogens such as Salmonella arrived in the New World from Europe. The existence of Salmonella Paratyphi C in Norway 300 years before it appeared in Mexico doesn’t prove that Europeans spread enteric fever to native Mexicans, says Schroeder, but that hypothesis is reasonable. A small percentage of people infected with Salmonella Paratyphi C carry the bacterium without falling ill, so apparently healthy Spaniards could have infected Mexicans who lacked natural resistance. Paratyphi C is transmitted through faecal material, and a collapse of social order during the Spanish conquest might have led to the poor sanitary conditions that are ripe for Salmonella spread, Krause and his team note in the paper. Krause’s study offers a blueprint for identifying the pathogens behind ancient outbreaks, says Schroeder. His own team plans to look for ancient pathogens in Caribbean burial sites that seem to be linked to catastrophic outbreaks, and that were established after the Europeans arrived. “The idea that some of them might have been caused by Salmonella is now a distinct possibility,” he says.


News Article | February 22, 2017
Site: www.scientificamerican.com

In 1896 archaeologists excavating Pueblo Bonito, a 650-room, multistory brick edifice in northwestern New Mexico’s Chaco Canyon, found the remains of 14 people in a burial crypt. Necklaces, bracelets and other jewelry made up of thousands of turquoise and shell beads accompanied the bones. The artifacts signaled that these individuals were elite members of the ancient Chaco society, one of the most important civilizations in the American Southwest. The excavations at Pueblo Bonito revealed the splendors of Chaco culture, which flourished between about A.D. 800 and 1250. The ancient Chacoans constructed at least a dozen great houses like Pueblo Bonito in Chaco Canyon during its heyday, and dozens of other Chacoan settlements thrived in what is today the Four Corners region where the borders of New Mexico, Colorado, Arizona and Utah meet. Soon after the excavations ended, archaeologists whisked these human remains off to the American Museum of Natural History (AMNH) in New York City, where most of them have resided ever since. Every so often researchers take the skulls out of their cardboard storage boxes on the museum’s 5th floor and remove the rest of the bones from wooden drawers lining a nearby hallway, laying them out on long tables to study them. They want to know how these people were related to one another and what this elite group might say about how Chaco society was organized. But they have had only limited clues. Continuing excavations at Chaco over the years have suggested that most people lived in smaller adobe residences surrounding the great houses, leading the majority of archaeologists to conclude Chaco society was hierarchically structured: Elite groups had dominion over cultural, religious and political life and enjoyed special privileges. Now an analysis of DNA from the Pueblo Bonito remains is providing intimate new details about these elite groups and who belonged to them. In a paper published online this week in Nature Communications researchers report the remains belonged to a single maternal line—what the team calls a matrilineal “dynasty”—that lasted for centuries. Other scientists hailed the research as a technical tour de force that helps fulfill the promise of ancient DNA to reveal the lives of ancient peoples. But not everyone agrees with the team’s conclusions, and some experts have criticized their decision not to consult with indigenous groups before going ahead with the research. Archaeologists Douglas Kennett at The Pennsylvania State University, Stephen Plog of the University of Virginia and their colleagues took a multipronged approach to studying the Pueblo Bonito remains. They first obtained direct radiocarbon dates from 11 of the burials, which ranged from between A.D. 800 and 850 for the earliest to about 1130 for the latest. The dates established that the burials spanned a period of some 330 years. Next the team extracted so-called mitochondrial DNA (mtDNA) from the remains. Mitochondria are tiny subcellular bodies that serve as the power plants for living cells, and their DNA is only inherited via the mother. The researchers were able to sequence an average of 98 percent of the mtDNA from nine individuals spanning the entire 330-year chronological sequence. Remarkably, all nine sequences were identical, meaning that each generation descended from the same original maternal ancestor. Finally, in an effort to tease out specific family relationships, the team sequenced nuclear DNA—which is inherited from both the mother and father—from six of the burials. These sequences suggested that at least two pairs of individuals were very closely related and probably represented a mother–daughter and grandmother–grandson relationship. The authors argue this elite group, in which power and influence flowed from mothers to their children, ruled at Pueblo Bonito from the earliest days of its founding around A.D. 800. Plog says the group’s clout probably stemmed from its control of ritual practices at Pueblo Bonito, as evidence by the discovery of objects such as carved wooden flutes and ceremonial staffs in the burial crypt. The study provides “impressively high resolution” of these matrilineal family ties, says Johannes Krause, a paleogeneticist at Max Planck Institute for the Science of Human History in Germany. Jennifer Raff, an anthropologist at the University of Kansas, agrees. “Paleogenomics approaches like this one can give us insights into the lives of ancient peoples on a scale never before possible.” Neither were involved with the study. The team’s interpretation of the genetic results makes sense to a number of outside researchers. “This indicates that hereditary leadership was present at the time of Pueblo Bonito’s founding” rather than gradually developing later as some earlier studies had suggested, says Jill Neitzel, an archaeologist at the University of Delaware. “The data show a group of related women, and some men, who can be argued to have been the persistent leaders of Pueblo Bonito for more than 300 years,” says Paul Reed, an archaeologist with Tucson, Ariz.–based Archaeology Southwest. “This research provides some of the most important information about Chaco in many decades,” says Paul Minnis, an anthropologist at the University of Oklahoma. “While most every scholar recognizes that Chaco was centrally organized, the nature of that organization has remained maddeningly opaque.” Yet Minnis and others question whether the team is right to call this elite group a dynasty, a term that usually refers to kings and queens who exercise sole rule over vast territories and populations. The Pueblo Bonito group “was clearly an important one,” says Barbara Mills, an anthropologist at the University of Arizona in Tucson. “But was it the only one?” In her view the findings do not prove their power and influence stretched beyond Pueblo Bonito itself, to include all of Chaco Canyon or even the wider “Chaco world.” Nevertheless, the authors argue their results may resolve another longstanding question. Today’s Pueblo peoples claim, on fairly firm archaeological grounds, to be the direct descendants of the Chacoans; so do the Navajo, on whose land Chaco Canyon now sits. In many modern Pueblo groups, including the Hopi and Zuni of Arizona and New Mexico, respectively, descent and inheritance are determined by one’s membership in a maternal clan. (A similar arrangement prevails among Orthodox and some Conservative Jews, for whom Jewish identity depends on having a Jewish mother.) Did they inherit this arrangement from their ancient Chacoan ancestors? Or, as archaeologist John Ware of the Amerind Foundation in Arizona has argued, did early kinship ties in Chaco society give way to rule by so-called “sodalities” based on shared ritual knowledge and practices, such as priests and brotherhoods, in which case some modern Pueblos may have developed their matrilineal organization independently? Kennett, Plog and their colleagues argue their findings support the hypothesis of direct continuity between Chacoan matrilines and those of many Pueblo groups today. Even as the work lends new support to the affinities between modern indigenous groups and ancient Chacoans, the researchers’ efforts have landed them in a minefield of research ethics. In 1990 Congress passed the Native American Graves Protection and Repatriation Act (NAGPRA), which dictates human remains and other artifacts found on federal or tribal lands must be repatriated to tribal groups if they can successfully establish a direct cultural relationship to them. In some instances such as the famed controversy over the 8,500-year-old Kennewick Man from Washington State, Native Americans and researchers have fought bitterly over who had right of possession. In the case of the Chaco remains the AMNH decided the NAGPRA did not apply, meaning the researchers were not legally required to get approval from the tribes before conducting research on the remains. In a statement approved by the paper’s 14 authors, the team said that in deciding to not consult the tribes, it relied on the AMNH’s determination that “the cultural complexity of the region made it impossible to establish a clear ancestor–descendant relationship with specific modern communities based on existing data.” The AMNH, in a separate statement, said “the research had considerable scientific merit with little impact on the artifacts and human remains,” adding that it had contacted “potentially affiliated tribes” during the late 1990s but that “none came forward to claim affiliation.” But that decision does not sit well with some critics. “Despite the fact the authors’ work was technically legal, the ethics here are questionable,” says Chaco researcher Ruth Van Dyke of Binghamton University in New York State. “Studies using ancient indigenous DNA should not be done without tribal consultation.” Rebecca Tsosie, a law professor of Native American descent at the University of Arizona who specializes in tribal and U.S. Indian law, agrees. “I am dismayed that there was not an effort to engage contemporary tribal leaders prior to undertaking and publishing this study,” Tsosie says, adding that the research is a “prime example” of “a study by cultural outsiders to dictate the truth of the history and structure of governance of the cultural insiders, Pueblo Indian nations.” Team member George Perry, an ancient DNA expert at Penn State, says that whereas the researchers did not formally consult with tribal leaders nor seek their approval to carry out the study beforehand, he is now “working diligently to engage with multiple groups in the Southwest” to “present and discuss the results of the research.” Getting the blessing of indigenous groups may be key to further research because there are other burials at Pueblo Bonito and other Chacoan sites yet to be studied. Moreover, some archaeologists say, some indigenous people might eventually opt to have their own DNA sequenced to see how closely related they might be to ancient Chacoan ancestors—a step taken by at least one Washington State tribal group that turned out to have a close genetic affiliation with Kennewick Man. In that example the scientific evidence backed up tribal arguments for repatriation of what they call “The Ancient One,” and its remains were reinterred by Northwest tribes on February 18 in a secret location. Some archaeologists are hoping the new study will be just a first step toward a fuller and more detailed understanding of how the ancient Chacoans lived. “How this matriline functioned in the ritual, social and political life of the Chacoans demands more research,” Minnis says. Until other burials can be studied, “we cannot answer the question as to whether the Pueblo Bonito matriline was recognized only by that community or by Chaco as a whole.”


News Article | February 15, 2017
Site: www.eurekalert.org

The development of agriculture is frequently seen as one of the major economic, social, and demographic thresholds in human history. From the perspective of the modern world it is often seen as an inevitable, desirable subsistence strategy, allowing larger populations, settled life, and the development of cities. Likewise it has even been argued that long-term human survival in tropical forests must have been impossible without some form of agricultural system, with agriculture developing as a result of climatic or environmental instability. However, these claims seem to be incorrect in the case of tropical New Guinea, as a recent study by a research crew from the Max Planck Institute for the Science of Human History, the University of Otago, and the University of Oxford has demonstrated. In tropical New Guinea, where one of the earliest human experiments with agriculture occurred, agriculture apparently never replaced foraging as a primary subsistence strategy: "Montane tropical forest environments provided a stable source of subsistence for human hunter-gatherers in New Guinea", says Patrick Roberts, primary author of the study. "We have found out that foragers were living in close proximity to emerging farming groups, from 12,000 to 300 years ago, which indicates that agriculture was not a forced event in this part of the world." Tropical forests have frequently been perceived as unattractive habitats for humans - both foragers and farmers - due to poor soils, difficulties of humidity, and issues of reliable nutrition. However, archaeological work in New Guinea, among other tropical regions, has now helped to refute this idea: "We can now affirm that humans have occupied areas in this region, covered today in rainforest, from 45,000 years ago", says..., Professor Glenn Summerhayes from the University of Otago, senior author of the study. "Some of the earliest evidence for the human development of agriculture comes precisely from the tropical forested portions of New Guinea." Nevertheless, as Professor Summerhayes states "records of past environments that can be directly associated with these prehistoric human experiments are currently frequently lacking, meaning that the context of agriculture and wider human behaviour in this region remain poorly understood". The recent study published in Nature Ecology and Evolution has addressed this gap in knowledge for the region by applying stable carbon and oxygen isotope analysis of fossil teeth to small regional mammals, like fruit bats, cuscus, ring-tailed possums, and macropods, to reconstruct the diets and environments of past human and animal populations. As Professor Julia Lee-Thorp from the University of Oxford, co-author of the study, points out, "it is only relatively recently that this method has been applied to small mammals. Due to their short life cycles and specialised adaptations, these animals are highly sensitive to environmental change making them perfect for obtaining a truly 'local' picture of vegetation". The team analysed the teeth of fruit bats, cuscus, ring-tailed possum and macropods from the archaeological site of Kiowa, which spans the origins of agriculture in the region (12,000-8,000 years ago), and beyond until around 300 years ago. These animals are locally well-studied, have known ecological behaviours, and are documented as being hunted by local foragers into recorded history. The results provided a new, rare environmental record for the Central Highlands of New Guinea that indicated a stability, and persistent use, of local tropical forest environments across the period of human occupation of the site. "This research enriches our understanding of the origins of agriculture in the region, indicating that stable tropical environments supported both agricultural experimentation and ongoing tropical forest foraging within a small area", states Dylan Gaffney of the University of Otago. "While intensive landscape modification and the domestication of plant taxa, including the banana, yam, and taro, occurred nearby, foragers continued to hunt and forage in tropical forest environments" states lead author, Patrick Roberts, of the Max Planck Institute for the Science of Human History. Human survival in New Guinea - a continuum of farming and foraging "While we often assume that agriculture is a desirable invention that replaced previous ways of obtaining food, in prehistoric New Guinea, agriculture is best seen as one part of a continuum of human survival strategies and certainly not as an inevitable development", says Roberts. This work also demonstrates how new methods, such as stable isotope analysis of tooth enamel and laser scanning from aircraft, are deepening archaeological knowledge of past human tropical forest use, where poor preservation, due to acidic soils and heavy rainfall, and difficulty of survey, due to dense vegetation, have often limited archaeological research. "The successful long-term exploitation of these environments is a key part of the adaptive flexibility that characterises our species relative to our ancestors. Humans have been able to exploit them continuously, and in diverse ways, since their first arrival there 45,000 years ago until the present-day where the expansion of plantations, industry and urbanism threaten their ongoing existence", concludes Roberts. For more information, please contact the Max Planck Institute for the Science of Human History News Office at +49 (0)3641 686 601 or email: presse@shh.mpg.de The paper, 'Persistent tropical foraging in the highlands of terminal Pleistocene/Holocene New Guinea' is by Patrick Roberts, Dylan Gaffney, Julia Lee-Thorp and Glenn Summerhayes. The paper was co-authored by the Max Planck Institute for the Science of Human History, the University of Otago and the University of Oxford

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