The Roman people, genetically stable and homogeneous? Certainly not, according to new archaeo-genetic work, corroborating the great genetic transitions of this people over 12,000 years with two great waves of migrations linked to agriculture and trade.
At its height, the ancient Roman Empire encompassed the entire Mediterranean and the lives of tens of millions of people in Europe, the Near East and North Africa.
Roman genetics, this shambles:twice, the people who were to become the Romans and finally the Italians of the center saw their genetic heritage upset, according to new European research combining archeology and DNA analysis. This work, published in Science , echo 12,000 years of history of the Roman people.
Long before Imperial Rome, involving Julius Caesar and his ilk, the Roman region was an important cultural crossroads between Europe and the Mediterranean. But if this ancient era is well documented, little information is known about the genetic mix of the region. By looking at the DNA of 127 individuals of the time from 29 archaeological sites in Rome and central Italy, researchers from the universities of Vienna, Stanford and Sapienza have analyzed the evolution of the origins of this people. Thanks to carbon-14 estimates or by inference from the archaeological context, each of these individuals could be placed on a frieze covering nearly 12,000 years of Roman prehistory and history.
From the Mesolithic to the Bronze Age:the arrival of agriculture
At the beginning, the Roman population of the Mesolithic period, 10,000 years before our era, showed little genetic diversity. The DNA of this time was indeed 30% less heterozygous than that of modern Romans, that is to say that the two copies that the human being has of each of his genes were often identical, indicating a weak genetic mixing. . But two major migrations to Rome will shake up this strong homogeneity.
The first transition occurred when Neolithic peasant farmers replaced Mesolithic hunter-gatherers around 7,000 BCE. The population was then enriched by an influx of farmers, mainly from Turkey and Iran, between 5,000 and 3,000 years before our era. This transition coincided with the introduction of domestic products such as wheat, barley, pulses, sheep and cattle in Italy.
From the Bronze Age to the founding of Rome:trade opens borders
Roman genetics, this shambles:twice, the people who were to become the Romans and finally the Italians of the center saw their genetic heritage upset, according to new European research combining archeology and DNA analysis. This work, published in Science , echo 12,000 years of history of the Roman people.
Long before Imperial Rome, involving Julius Caesar and his ilk, the Roman region was an important cultural crossroads between Europe and the Mediterranean. But if this ancient era is well documented, little information is known about the genetic mix of the region. By looking at the DNA of 127 individuals of the time from 29 archaeological sites in Rome and central Italy, researchers from the universities of Vienna, Stanford and La Sapienza have analyzed the evolution of the origins of this people. Thanks to carbon-14 estimates or by inference from the archaeological context, each of these individuals could be placed on a frieze covering nearly 12,000 years of Roman prehistory and history.
From the Mesolithic to the Bronze Age:the arrival of agriculture
At the beginning, the Roman population of the Mesolithic period, 10,000 years before our era, showed little genetic diversity. The DNA of this time was indeed 30% less heterozygous than that of modern Romans, that is to say that the two copies that the human being has of each of his genes were often identical, indicating a weak genetic mixing. . But two major migrations to Rome will shake up this strong homogeneity.
The first transition occurred when Neolithic peasant farmers replaced Mesolithic hunter-gatherers around 7,000 BCE. The population was then enriched by an influx of farmers, mainly from Turkey and Iran, between 5,000 and 3,000 years before our era. This transition coincided with the introduction of domestic products such as wheat, barley, pulses, sheep and cattle in Italy.
From the Bronze Age to the founding of Rome:trade opens borders
The second population transition took place during the Bronze Age, between 2,900 and 900 years before our era:an imprecise range because researchers lacked data. This change coincided with the intensification of exchanges and interactions with the populations of the Mediterranean - or Mare Nostrum , "our sea", as the Romans called it – by means of newly developed chariots and chariots and thanks to advances in navigation. Thus, at the latest in 900 BC, shortly before the founding of Rome traditionally dated to 753 BC, the population of the Iron Age was enriched by Iranian ancestors, steppes Ukrainians and North Africans… To the point of resembling, already, the modern Mediterranean population. "Unlike prehistoric individuals, Iron Age individuals genetically resemble modern European and Mediterranean individuals and display diverse origins, as central Italy becomes increasingly connected to distant communities through new networks of trade, colonization and conflict “, elaborate the researchers in the publication.
An Empire that encompasses the entire Mediterranean Sea
And it was just beginning. For although Rome began as a modest city, 800 years later it had taken control of an empire that stretched as far west as Britain, south to North Africa and east in Syria, Jordan and Iraq. The genetics of individuals at the time became richer and more complex again, mainly from the eastern Mediterranean, but little from the west. In support of these conclusions, the authors cite evidence of long-term settlement in Rome by people from the east, such as the birthplaces recorded in funerary inscriptions and the frequency of temples and shrines dedicated to the gods. Greeks, Phrygians, Syrians and Egyptians.
Why so little immigration from the west and so much from the east, when Gaul was conquered and provided its share of slaves, olive oil or wine? For the researchers, this could be explained by the higher population density in the eastern Mediterranean than in the west and the presence of megacities, such as Athens, Antioch and Alexandria, which may have led to a flow of people from east to west during antiquity.
A perpetual mutation, which can be read in the genomes
The centuries that followed were marked by turmoil:the empire split in two, diseases and wars decimated the population of Rome, and a series of invasions hit the city. Hence a reduction in contact with the eastern Mediterranean and an increase in gene flow from Europe. The ancestry of the population then shifted to northern and western Europe. Later, the rise and rule of the Holy Roman Empire brought an influx of central and northern European ancestry.
The lesson is that the ancient world was constantly changing, both in terms of culture and ancestry, explains in a press release Jonathan Pritchard, one of the main authors of this work. "We were surprised at how quickly the ancestry of the population evolved, in just a few centuries, reflecting Rome's changing political alliances over time “, he adds. “Even in ancient times, Rome was a melting pot of different cultures ."
At its height, the ancient Roman Empire encompassed the entire Mediterranean and the lives of tens of millions of people in Europe, the Near East and North Africa. At its center, the city of Rome is the first to reach more than one million inhabitants in the ancient world. A size that would remain unmatched in Europe until the dawn of the industrial revolution, nearly 1,500 years later.