Scholars have been studying Rome for hundreds of years, but it still holds some secrets – for instance, relatively little is known about the ancestral origins of the city’s denizens. Now, an international team of researchers is filling in the gaps with a genetic history that shows just how much the Eternal City’s populace mirrored its sometimes tumultuous history.
The study, published this month in Science, focuses on the ancient DNA of individuals from Rome and adjacent regions in Italy. Those genetic data reveal at least two major migrations into Rome, as well as several smaller but significant population shifts over just the last few thousand years. The DNA analysis also revealed that as the Roman Empire expanded around the Mediterranean Sea, immigrants from the Near East, Europe and North Africa pulled up their roots and moved to Rome.
“This study shows how dynamic the past really is,” said Hannah Moots, a graduate student in anthropology and co-lead author on the new study. “In Rome we’re seeing people come from all over, in ways that correspond with historical political events.”
In the last decade or so, an increasing number of studies have used DNA sampled from ancient skeletons to fill in important details of human history. Rome presented an interesting opportunity to use the same ancient DNA techniques to fill in details left out of the historical record. Jonathan Pritchard, a professor of genetics and biology at Stanford, says “The historical and archaeological records tell us a great deal about political history and contacts of different kinds with different places – trade and slavery, for example – but those records provide limited information about the genetic makeup of the population.”
To find out what that makeup looked like, the Stanford team partnered with a host of European researchers, including senior authors Alfredo Coppa, a professor of physical anthropology at Sapienza University, and Ron Pinhasi, an associate professor of evolutionary anthropology at the University of Vienna, to gather 127 human DNA samples from 29 sites in and around Rome dating from between the Stone Age and medieval times.
“In our study,” comments Alfredo Coppa, “we used the collaboration and support of a large number of archaeologists, who opened their archives to us, and allowed us to better understand what genetic data was highlighting.”
An analysis of some of the earliest samples more or less comports with what has been found around Europe – they represent an influx of farmers primarily descended from early agriculturalists from Turkey and Iran around 8,000 years ago, followed by a shift toward ancestry from the Ukrainian steppe somewhere between 5,000 and 3,000 years ago. By the founding of Rome, traditionally dated to 753 BCE, the city’s population had grown in diversity and resembled modern European and Mediterranean peoples.
Republic, empire and beyond
Although Rome began as a humble city-state, within 800 years it had gained control over an Empire extending as far west as Britain, south into North Africa and east into Syria, Jordan and Iraq.
As the empire expanded, it facilitated the movement and interaction of people through trade networks, new road infrastructure, military campaigns, and slavery. Contemporary accounts and archaeological evidence support tight connections between Rome and all other parts of the empire – in fact, the daily life of Rome relied heavily on trade goods from other parts of the empire to supply its enormous urban center.
The researchers found that the genetic corroborates but also complicates the historical record. There was a massive shift in Roman residents’ ancestry, but that ancestry came primarily from the Eastern Mediterranean and Near East, possibly because of denser populations there relative to the Roman Empire’s western reaches in Europe and Africa.
The next several centuries were full of turmoil: the capital’s move to Constantinople and subsequent split of the Empire, disease outbreaks that decimated the population of Rome and a series of invasions, including the Visigoth’s sacking of Rome in 410 CE, when, as Saint Jerome put it, “the bright light of all the world was put out.” These events left their mark on the city’s ancestry, which shifted away from eastern Mediterranean and toward western European. Similarly, the rise and reign of the Holy Roman Empire brought an influx of central and northern European ancestry.
Migration is nothing new
The study shows that the ancient world was perpetually in flux, both in terms of culture and ancestry. “It was surprising to us how rapidly the population ancestry shifted, over timescales of just a few centuries, reflecting Rome’s shifting political alliances over time,” Pritchard said. “Another striking aspect was how cosmopolitan the population of Rome was, starting more than 2,000 years ago and continuing through the rise and dissolution of the empire. Even in antiquity, Rome was a melting pot of different cultures.”
In future studies, the researchers hope to expand the geographic range of ancient DNA they can sample and to study the evolution of traits like height, lactose tolerance and resistance to diseases such as malaria that may have changed over time. “We now need to think about new studies which look at the interaction between people of different social classes across the Roman Empire, including not only the movements of particular groups from different regions, but also of social mobility in both core regions, and the various provinces” says Ron Pinhasi.
The article “Ancient Rome: A genetic crossroads of Europe and the Mediterranean,” appears in Science Vol. 366, Issue 6466 (2019). Click here to access it.
Top Image: 13th century manuscript showing the building of Rome – British Library MS Additional 15268 f.156