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Thousands of horsemen may have swept into Bronze Age Europe, transforming the local population
http://www.sciencemag.org/news/2017/...et_cid=1178069
It's interesting to note that it's not just recent generations that can be won over by the offer of a bit of bling.
When did humans settle down? The house mouse may have the answer
http://www.sciencemag.org/news/2017/...et_cid=1240257
Update 10/04/2017
There's no such thing as a 'pure' European—or anyone else
http://www.sciencemag.org/news/2017/...et_cid=1328086
Update 16/05/2017
Migration—the choices we face....by Mohamed H. A. Hassan
http://science.sciencemag.org/content/356/6339/667.full
Update 18/05/2017
http://www.sciencemag.org/news/2017/...et_cid=1178069
Call it an ancient thousand man march. Early Bronze Age men from the vast grasslands of the Eurasian steppe swept into Europe on horseback about 5000 years ago—and may have left most women behind. This mostly male migration may have persisted for several generations, sending men into the arms of European women who interbred with them, and leaving a lasting impact on the genomes of living Europeans.
“It looks like males migrating in war, with horses and wagons,” says lead author and population geneticist Mattias Jakobsson of Uppsala University in Sweden.
Europeans are the descendants of at least three major migrations of prehistoric people. First, a group of hunter-gatherers arrived in Europe about 37,000 years ago. Then, farmers began migrating from Anatolia (a region including present-day Turkey) into Europe 9000 years ago, but they initially didn’t intermingle much with the local hunter-gatherers because they brought their own families with them. Finally, 5000 to 4800 years ago, nomadic herders known as the Yamnaya swept into Europe. They were an early Bronze Age culture that came from the grasslands, or steppes, of modern-day Russia and Ukraine, bringing with them metallurgy and animal herding skills and, possibly, Proto-Indo-European, the mysterious ancestral tongue from which all of today’s 400 Indo-European languages spring. They immediately interbred with local Europeans, who were descendants of both the farmers and hunter-gatherers. Within a few hundred years, the Yamnaya contributed to at least half of central Europeans’ genetic ancestry.
To find out why this migration of Yamnaya had such a big impact on European ancestry, researchers turned to genetic data from earlier studies of archaeological samples. They analyzed differences in DNA inherited by 20 ancient Europeans who lived just after the migration of Anatolian farmers (6000 to 4500 years ago) and 16 who lived just after the influx of Yamnaya (3000 to 1000 years ago). The team zeroed in on differences in the ratio of DNA inherited on their X chromosomes compared with the 22 chromosomes that do not determine sex, the so-called autosomes. This ratio can reveal the proportion of men and women in an ancestral population, because women carry two X chromosomes, whereas men have only one.
Europeans who were alive from before the Yamnaya migration inherited equal amounts of DNA from Anatolian farmers on their X chromosome and their autosomes, the team reports today in the Proceedings of the National Academy of Sciences. This means roughly equal numbers of men and women took part in the migration of Anatolian farmers into Europe.
But when the researchers looked at the DNA later Europeans inherited from the Yamnaya, they found that Bronze Age Europeans had far less Yamnaya DNA on their X than on their other chromosomes. Using a statistical method developed by graduate student Amy Goldberg in the lab of population geneticist Noah Rosenberg at Stanford University in Palo Alto, California, the team calculated that there were perhaps 10 men for every woman in the migration of Yamnaya men to Europe (with a range of five to 14 migrating men for every woman). That ratio is “extreme”—even more lopsided than the mostly male wave of Spanish conquistadores who came by ship to the Americas in the late 1500s, Goldberg says.
Such a skewed ratio raises red flags for some researchers, who warn it is notoriously difficult to estimate the ratio of men to women accurately in ancient populations. But if confirmed, one explanation is that the Yamnaya men were warriors who swept into Europe on horses or drove horse-drawn wagons; horses had been recently domesticated in the steppe and the wheel was a recent invention. They may have been “more focused on warfare, with faster dispersal because of technological inventions” says population geneticist Rasmus Nielsen of the University of California, Berkeley, who is not part of the study.
But warfare isn’t the only explanation. The Yamnaya men could have been more attractive mates than European farmers because they had horses and new technologies, such as copper hammers that gave them an advantage, Goldberg says.
The finding that Yamnaya men migrated for many generations also suggests that all was not right back home in the steppe. “It would imply a continuing strongly negative push factor within the steppes, such as chronic epidemics or diseases,” says archaeologist David Anthony of Hartwick College in Oneonta, New York, who was not an author of the new study. Or, he says it could be the beginning of cultures that sent out bands of men to establish new politically aligned colonies in distant lands, as in later groups of Romans or Vikings.
“It looks like males migrating in war, with horses and wagons,” says lead author and population geneticist Mattias Jakobsson of Uppsala University in Sweden.
Europeans are the descendants of at least three major migrations of prehistoric people. First, a group of hunter-gatherers arrived in Europe about 37,000 years ago. Then, farmers began migrating from Anatolia (a region including present-day Turkey) into Europe 9000 years ago, but they initially didn’t intermingle much with the local hunter-gatherers because they brought their own families with them. Finally, 5000 to 4800 years ago, nomadic herders known as the Yamnaya swept into Europe. They were an early Bronze Age culture that came from the grasslands, or steppes, of modern-day Russia and Ukraine, bringing with them metallurgy and animal herding skills and, possibly, Proto-Indo-European, the mysterious ancestral tongue from which all of today’s 400 Indo-European languages spring. They immediately interbred with local Europeans, who were descendants of both the farmers and hunter-gatherers. Within a few hundred years, the Yamnaya contributed to at least half of central Europeans’ genetic ancestry.
To find out why this migration of Yamnaya had such a big impact on European ancestry, researchers turned to genetic data from earlier studies of archaeological samples. They analyzed differences in DNA inherited by 20 ancient Europeans who lived just after the migration of Anatolian farmers (6000 to 4500 years ago) and 16 who lived just after the influx of Yamnaya (3000 to 1000 years ago). The team zeroed in on differences in the ratio of DNA inherited on their X chromosomes compared with the 22 chromosomes that do not determine sex, the so-called autosomes. This ratio can reveal the proportion of men and women in an ancestral population, because women carry two X chromosomes, whereas men have only one.
Europeans who were alive from before the Yamnaya migration inherited equal amounts of DNA from Anatolian farmers on their X chromosome and their autosomes, the team reports today in the Proceedings of the National Academy of Sciences. This means roughly equal numbers of men and women took part in the migration of Anatolian farmers into Europe.
But when the researchers looked at the DNA later Europeans inherited from the Yamnaya, they found that Bronze Age Europeans had far less Yamnaya DNA on their X than on their other chromosomes. Using a statistical method developed by graduate student Amy Goldberg in the lab of population geneticist Noah Rosenberg at Stanford University in Palo Alto, California, the team calculated that there were perhaps 10 men for every woman in the migration of Yamnaya men to Europe (with a range of five to 14 migrating men for every woman). That ratio is “extreme”—even more lopsided than the mostly male wave of Spanish conquistadores who came by ship to the Americas in the late 1500s, Goldberg says.
Such a skewed ratio raises red flags for some researchers, who warn it is notoriously difficult to estimate the ratio of men to women accurately in ancient populations. But if confirmed, one explanation is that the Yamnaya men were warriors who swept into Europe on horses or drove horse-drawn wagons; horses had been recently domesticated in the steppe and the wheel was a recent invention. They may have been “more focused on warfare, with faster dispersal because of technological inventions” says population geneticist Rasmus Nielsen of the University of California, Berkeley, who is not part of the study.
But warfare isn’t the only explanation. The Yamnaya men could have been more attractive mates than European farmers because they had horses and new technologies, such as copper hammers that gave them an advantage, Goldberg says.
The finding that Yamnaya men migrated for many generations also suggests that all was not right back home in the steppe. “It would imply a continuing strongly negative push factor within the steppes, such as chronic epidemics or diseases,” says archaeologist David Anthony of Hartwick College in Oneonta, New York, who was not an author of the new study. Or, he says it could be the beginning of cultures that sent out bands of men to establish new politically aligned colonies in distant lands, as in later groups of Romans or Vikings.
The Yamnaya men could have been more attractive mates than European farmers because they had horses and new technologies, such as copper hammers that gave them an advantage,
When did humans settle down? The house mouse may have the answer
http://www.sciencemag.org/news/2017/...et_cid=1240257
Sometime about 10,000 years ago, the earliest farmers put down their roots—literally and figuratively. Agriculture opened the door to (theoretically) stable food supplies, and it let hunter-gatherers build permanent dwellings that eventually morphed into complex societies in many parts of the world. But how that transition played out is a contentiously debated topic. Now, a new study shows that our path to domesticity zig-zagged between periods of sedentary life and a roaming hunter-gatherer lifestyle. The evidence? The presence—and absence—of the common house mouse.
“It’s remarkable, using a lowly house mouse to monitor a major milestone in human history,” says Melinda Zeder, curator of Old World archaeology at the Smithsonian National Museum of Natural History in Washington, D.C., who wasn’t involved with the study. “It’s really a masterful way of monitoring sedentism.”
To explore the transition to agriculture, scientists have looked to the Natufians, an ancient hunter-gatherer society that flourished from about 12,500 to 9500 B.C.E. in a part of the Middle East called the Levant, which includes pieces of modern-day Cyprus, Syria, Israel, Jordan, Lebanon, and Palestine. The Natufians were among the first people known to domesticate animals—dogs and hogs—and may have been the first to transition to farming. As they moved from seasonally collecting acorns and hunting gazelle to farming wheat and barley, many researchers think they went through an intermediary phase: a semisedentary period in which they built stone dwellings but still hunted for sustenance and moved on when resources became scarce. But evidence of exactly when and how humans became sedentary has been hard to come by.
So Thomas Cucchi, an archaeologist at the University of Aberdeen in the United Kingdom, decided to turn to the creatures living alongside humans at the time, specifically house mice (Mus domesticus), which live almost exclusively in or near houses and planted fields. He teamed up with Lior Weissbrod, a fellow archaeologist at the University of Haifa in Israel, who was analyzing wild and domesticated mice living today in Kenya.
“It’s remarkable, using a lowly house mouse to monitor a major milestone in human history,” says Melinda Zeder, curator of Old World archaeology at the Smithsonian National Museum of Natural History in Washington, D.C., who wasn’t involved with the study. “It’s really a masterful way of monitoring sedentism.”
To explore the transition to agriculture, scientists have looked to the Natufians, an ancient hunter-gatherer society that flourished from about 12,500 to 9500 B.C.E. in a part of the Middle East called the Levant, which includes pieces of modern-day Cyprus, Syria, Israel, Jordan, Lebanon, and Palestine. The Natufians were among the first people known to domesticate animals—dogs and hogs—and may have been the first to transition to farming. As they moved from seasonally collecting acorns and hunting gazelle to farming wheat and barley, many researchers think they went through an intermediary phase: a semisedentary period in which they built stone dwellings but still hunted for sustenance and moved on when resources became scarce. But evidence of exactly when and how humans became sedentary has been hard to come by.
So Thomas Cucchi, an archaeologist at the University of Aberdeen in the United Kingdom, decided to turn to the creatures living alongside humans at the time, specifically house mice (Mus domesticus), which live almost exclusively in or near houses and planted fields. He teamed up with Lior Weissbrod, a fellow archaeologist at the University of Haifa in Israel, who was analyzing wild and domesticated mice living today in Kenya.
There's no such thing as a 'pure' European—or anyone else
http://www.sciencemag.org/news/2017/...et_cid=1328086
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.
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.
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.
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.
Update 16/05/2017
Migration—the choices we face....by Mohamed H. A. Hassan
http://science.sciencemag.org/content/356/6339/667.full
More than 1 million refugees and migrants arrived in Europe in 2015, and nearly 390,000 more in 2016, many fleeing conflict in the Middle East and North Africa. European leaders have often accommodated the migrants with admirable generosity, even while facing stiff political opposition. Yet, if developed countries focus only on immediate domestic impacts of mass migration, they will miss a critical point: When thousands of people, including many researchers, leave their home countries, the exodus perpetuates instability in those countries and damages prospects for future development.
Before the Syrian conflict began in 2011, the country had 31,000 doctors. Today, roughly half are gone, many scattered to adjacent countries, Europe, and North America. Uncounted thousands of scientists, engineers, and advanced students from across the region have joined them. How can nations rebuild and progress when much of their scientific workforce has fled? How can they hope to raise farm output, improve public health, or prepare for natural disaster?
This core dilemma of migration will confront leaders of the G7 developed nations when they convene 26 to 27 May. Sustained development in poor countries is essential to easing migration, but developed countries have an uneven record in making necessary investments. Today, the scale of migration is unprecedented and the needs are more urgent. Mass migration is emerging as a permanent feature of geopolitical stress and global change.
The United Nations (UN) High Commissioner for Refugees reports that, at the end of 2015, nearly 41 million people were internally displaced, while almost 25 million were refugees or asylum-seekers. They are driven from their homes by conflict, economic insecurity, climate disruption, or a combination of these. Migration can destabilize adjacent countries, which are often economically and politically vulnerable. But political tension and xenophobia also reflect the power of migration to disrupt countries in North America, Europe, and Australia.
Sub-Saharan Africa illustrates choices confronting policy-makers. From one perspective, it is a time of optimism: Economic growth is robust. Hunger is in retreat. Life spans are on the rise. A building boom in new universities shows that leaders understand the power of knowledge—especially science and technology—to drive growth. Still, sub-Saharan Africa remains desperately poor. Political instability is widespread. Many universities lack qualified faculty. Population will grow from 1.2 billion today to a projected 2.5 billion by 2050. If Africa cannot grow and develop fast enough to provide education and jobs for its young people, then millions may see migration as their best option.
The UN Sustainable Development Goals were created in part to address such issues. But none of the Least Developed Countries can achieve this growth and development without partners. It is thus an acutely important moment for the G7 countries—and science is more capable than ever of providing support.
The World Academy of Sciences, and other academies and organizations that support at-risk scientists, can offer fellowships, training, and resources so that refugee scientists can contribute to their new countries and someday help to rebuild their home countries. Social scientists can provide vital research on migration, from drivers to integration and financial impact. Science diplomacy, crucially, must help bring countries together for cooperative efforts. And building science is a focus of aid programs advanced by the European Union, and by countries such as Germany, the United Kingdom, Sweden, and Italy.
But developed countries are not alone in this mission. Nations of the South share responsibility, and migration should be taken up more energetically by the G20 countries, including Brazil, China, India, and South Africa, which convene in July. Researchers in even the poorest countries have a direct interest in migration, and an increasing capacity to contribute to solutions.
Sub-Saharan Africa illustrates choices confronting policy-makers. From one perspective, it is a time of optimism: Economic growth is robust. Hunger is in retreat. Life spans are on the rise. A building boom in new universities shows that leaders understand the power of knowledge—especially science and technology—to drive growth. Still, sub-Saharan Africa remains desperately poor. Political instability is widespread. Many universities lack qualified faculty. Population will grow from 1.2 billion today to a projected 2.5 billion by 2050. If Africa cannot grow and develop fast enough to provide education and jobs for its young people, then millions may see migration as their best option.
The UN Sustainable Development Goals were created in part to address such issues. But none of the Least Developed Countries can achieve this growth and development without partners. It is thus an acutely important moment for the G7 countries—and science is more capable than ever of providing support.
The World Academy of Sciences, and other academies and organizations that support at-risk scientists, can offer fellowships, training, and resources so that refugee scientists can contribute to their new countries and someday help to rebuild their home countries. Social scientists can provide vital research on migration, from drivers to integration and financial impact. Science diplomacy, crucially, must help bring countries together for cooperative efforts. And building science is a focus of aid programs advanced by the European Union, and by countries such as Germany, the United Kingdom, Sweden, and Italy.
But developed countries are not alone in this mission. Nations of the South share responsibility, and migration should be taken up more energetically by the G20 countries, including Brazil, China, India, and South Africa, which convene in July. Researchers in even the poorest countries have a direct interest in migration, and an increasing capacity to contribute to solutions.
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