DNA Analysis of Ancient Rome Reveals a Cosmopolitan Megacity
A new collection of DNA from ancient Romans spanning 12,000 years shows how the population of the empire’s capital shifted along with its politics. Published in Science, the timeline is one of the first to examine what genetic information from archaeological digs says about the region after the time of hunter-gatherers and early farmers.
The analysis found that ancient Romans were from all over Europe, the Near East and northern Africa. “Rome was a cosmopolitan, melting-pot kind of place,” says study coauthor Jonathan Pritchard, a geneticist at Stanford University. “It doesn’t match how most people think about ancient cities.” It wasn’t until about 3,000 years ago that the inhabitants of Rome started to genetically resemble modern residents.
So far, most studies of ancient European DNA — genetic material extracted from archaeological remains — have looked at earlier populations, like hunter-gatherers, Pritchard says. He and his collaborators wanted to see how more recent peoples, like those from the Roman empire, compare to our historical view of them.
The team collected remains from 127 individuals from 29 different archaeological sites in and around Rome — the oldest were from around 10,000 B.C. After crushing a small portion of each samples’ inner skull bones, the team extracted and sequenced DNA from the material. Putting the genomes in chronological order showed how the population of Rome changed over time.
The earliest samples collected from the region showed local hunter-gatherers resembled other, more western Europeans. About 7,000 years ago, the region saw its first demographic shift as farming began and people of Iranian ancestry started mixing into the population. Then, after the Iron Age kicked in, more individuals from the eastern European steppe region appeared. Both of these population trends are similar to what happened in Europe during those times, Pritchard says.