All roads lead to Imperial Rome, says one bioarcheologist, and she may or may not be right.
Remains of individual immigrants who had traveled to Rome thousands of years ago were unearthed in a 2,000-year-old cemetery located on the city's outskirts.
By examining the immigrants' skulls and teeth, researchers were able to discern that the individuals may have lived during the first to third centuries A.D., making them the first people identified as Imperial Rome migrants.
Experts believe that about one million people lived in Imperial Rome, in which immigrants took up 5 percent of the total population while slaves were accounted for 40 percent.
"This population ebbed and flowed," said bioarcheologist Kristina Killgrove. "You had people who were migrating in, and you had people who were dying and [people who were] migrating out."
Killgrove said Rome, being the Eternal City, may have been a hub for immigrants. Finding direct evidence in connection to that, however, has troubled scientists for decades.
To find an answer to that problem, Killgrove and her fellow researcher, Janet Montgomery, studied skeletal remains found at two cemeteries in Rome. They looked for specific isotopes of oxygen and strontium in the remnants.
After much analysis, the pair found several male skeletons, one female skeleton and several skeletons of children. All of them were likely to have not been born in Rome.
Eight of the ancient individuals were possibly migrants from North Africa, the Apennine Mountains, or the Alps. Five of them were still quite young.
Killgrove said the high number of youth immigrants was particularly intriguing, especially because voluntary migration was mostly done by adult men.
"Children and adolescents could have come to Rome to be educated, to become apprentices, to be married, as part of a family that migrated, or even as slaves," said Killgrove. The last bit was likelier, as slavery within the Roman Empire was quite established.
Meanwhile, Killgrove said they won't be able to tell from the isotope analysis how and what the individuals' status in society was when they were buried.
Additionally, carbon isotopes that reflected the carbohydrate consumption of the ancient individuals revealed that their diets must have changed when they moved to the Empire. Their meals were probably made up of wheat, fish, meat and legumes.
Lastly, Killgrove said further studies and DNA analysis is needed to be conducted to provide context for their findings. Their study is featured in the journal PLOS ONE.