I have long wondered how much of the modern Italian and Greek population descend from slaves imported from other countries. We have no idea at present if their genetic impact was minor (few slaves left descendants), moderate (e.g. 10% or 20% of modern genomes come from foreign slaves) or major (e.g. over half of the modern gene pool was inherited from slaves).
The only evidence we have of how much DNA ancient slaves contributed to modern gene pools is from Iceland. There, it looks like about 20% of male lineages and about 50% of female lineages today came from Irish and Scottish slaves brought by the Vikings. Looking at admixtures, modern Icelandic people are actually closer to the Irish than to the Swedes, so the maternal proportion (very difficult to assess from mtDNA haplogroups) could be even higher than 50%.
How would ancient Greek and Rome compare ? Considering that both the ancient Greeks and Romans relied much more on slaves to run their economy (mines, farms, road building, household work, entertainment), I would expect an even higher proportion.
Of course the Celts also kept slaves, but mostly other enslaves Celtic tribes. The Romans had such a large empire that they brought slaves from a great variety of regions and ethnic groups. The Greeks would have brought slaves mostly from the Balkans, Anatolia and Libya (before the Hellenistic period, at least).
It has been argued that slaves didn't procreate much as they weren't free. But that's nonsense. Slaves were valuable commodities, sold on markets. If you owned slaves, having them breed together created more wealth. So the more children they had the better. Additionally there is now ample evidence that the Romans liked to acquire beautiful female slaves (especially exotic blondes and redheads) for the purpose of sex, and that they often had children with them. These children were typically freed once their reached adolescence or adulthood. In fact, most of the freed slaves in ancient Rome could have been the offspring of Roman patricians with their slaves.
If that is the case, that genetic contribution of slaves wouldn't show up on the Y-DNA line, but nevertheless contributed a big share of the total admixture. However things are surely more complicated as there is a very clear north-south gradient for genetic admixtures in Italy. It is possible that northern Italy imported more slaves from Gaul, Germania, Pannonia and other northern regions, while southern Italy brought more slaves from North Africa and the eastern Mediterranean. But there is surely more to the story. That's why I am awaiting with great interest any data from ancient Rome and Greece.
It would be very interested to compare the genomes (and Y-DNA) of elite Greeks/Romans vs Greek/Roman slaves, and see the evolution over time. It is very doubtful that the Mycenaean elite was genetically close to the elite of Classical Greece, and I also suspect considerable regional variations between, say, Athens, Sparta, Ionia, etc.
The only evidence we have of how much DNA ancient slaves contributed to modern gene pools is from Iceland. There, it looks like about 20% of male lineages and about 50% of female lineages today came from Irish and Scottish slaves brought by the Vikings. Looking at admixtures, modern Icelandic people are actually closer to the Irish than to the Swedes, so the maternal proportion (very difficult to assess from mtDNA haplogroups) could be even higher than 50%.
How would ancient Greek and Rome compare ? Considering that both the ancient Greeks and Romans relied much more on slaves to run their economy (mines, farms, road building, household work, entertainment), I would expect an even higher proportion.
Of course the Celts also kept slaves, but mostly other enslaves Celtic tribes. The Romans had such a large empire that they brought slaves from a great variety of regions and ethnic groups. The Greeks would have brought slaves mostly from the Balkans, Anatolia and Libya (before the Hellenistic period, at least).
It has been argued that slaves didn't procreate much as they weren't free. But that's nonsense. Slaves were valuable commodities, sold on markets. If you owned slaves, having them breed together created more wealth. So the more children they had the better. Additionally there is now ample evidence that the Romans liked to acquire beautiful female slaves (especially exotic blondes and redheads) for the purpose of sex, and that they often had children with them. These children were typically freed once their reached adolescence or adulthood. In fact, most of the freed slaves in ancient Rome could have been the offspring of Roman patricians with their slaves.
If that is the case, that genetic contribution of slaves wouldn't show up on the Y-DNA line, but nevertheless contributed a big share of the total admixture. However things are surely more complicated as there is a very clear north-south gradient for genetic admixtures in Italy. It is possible that northern Italy imported more slaves from Gaul, Germania, Pannonia and other northern regions, while southern Italy brought more slaves from North Africa and the eastern Mediterranean. But there is surely more to the story. That's why I am awaiting with great interest any data from ancient Rome and Greece.
It would be very interested to compare the genomes (and Y-DNA) of elite Greeks/Romans vs Greek/Roman slaves, and see the evolution over time. It is very doubtful that the Mycenaean elite was genetically close to the elite of Classical Greece, and I also suspect considerable regional variations between, say, Athens, Sparta, Ionia, etc.