NEW YORK — A genomic analysis has found that the Etruscans who lived in central Italy during the Iron Age were closely related to neighboring populations, and their later genetic makeup was influenced by the reach of the Roman Empire.
There had been debate over the origins of Etruscans, who spoke a non-Indo-European language and had striking metallurgic skills, stretching back to the ancient Greeks. The writers Herodotus and Hellanicus of Lesbos suggested that the Etruscans originated from Anatolia or the Aegean, while Dionysius of Halicarnassus postulated they arose from local Bronze Age Villanovan groups.
With genomic data from 82 individuals that lived in Etruria and southern Italy over a span of nearly 2,000 years, an international team of researchers pieced together much of the population genetic history of the region. As they reported Friday in Science Advances, Etruscans had similar genetic profiles as those of their neighbors in Rome, despite their language differences, and had ancestry derived from steppe-related groups that arrived in the region during the Bronze Age. The genetic makeup of Etruscans then remained broadly stable but shifted with the establishment of the Roman Empire.
"Our genomic analyses find an autochthonous origin of the Etruscans as supported also by archeological evidence," first author Cosimo Posth from the University of Tübingen wrote in an email. "I was however surprised to observe such … genetic homogeneity for 800 years from the Iron Age to the Roman Republic period."
To establish this timeline, he and his colleagues genotyped 82 individuals who lived in Italy during three broad time periods: the Iron Age and Roman Republic, the Imperial period, and between 500 and 1,000 years ago.
Most of the individuals who lived in Etruria during the Iron Age and Roman Republic clustered together in a principal components analysis. This cluster harbored three genetic ancestries associated with Anatolian Neolithic farmers, European hunter-gatherers, and Bronze Age pastoralists from the Pontic-Caspian steppe, and overall could be modeled as a mix of other European populations, suggesting Etruscans originated in that region.
Further, the genetic ancestry of the Etruscan population from this time period was similar to that of Iron Age and Roman Republic individuals from Tuscany and Lazio, including the ancient city of Rome, even though Etruscans spoke a non-Indo-European-language.
Indo-European-languages spread across Europe during the Bronze Age in tandem with individuals who had steppe pastoralist ancestry, Posth noted, adding that this steppe ancestry was widespread in Italy during the Iron Age, including among Etruscan individuals.
"Therefore, we identified here a rare example of language continuity despite large-scale genetic replacement, and we suggest this might be due to a prolonged period of admixture between the incoming steppe ancestry and local populations, who largely maintained their cultural identity," he said.
The genetic makeup of Etruria changed during the Imperial Period, with an influx of ancestry related to Near East groups. "The Roman Empire had a transformative impact on the local gene pool," Posth said, adding that he and his colleagues suspect that the changes were due to the arrival of slaves, soldiers, and merchants from the Near East to Rome and outlying areas.
The region again experienced an influx of genetic ancestry, this time associated with Germanic individuals, during the Middle Ages when the Western Roman Empire collapsed. But between the Early Medieval time and present day, there has been broad genetic continuity.
Going forward, Posth said obtaining additional Bronze Age genetic data from central Italy could help analyze admixture patterns related to steppe ancestry and the spread of Indo-European languages, while gathering additional ancient genomes from the Roman Imperial period could help to examine whether the genetic replacement observed in central Italy during that time occurred across the Italian peninsula.