Something long believed by anthropologists and prehistorians is receiving support from ancient DNA data. Cities were population sinks, where people traveled or even moved to make money but died in higher numbers. They were places of cultural life but physical death. There was art, trade, wealth, and mixing of peoples, but also disease (both fatal and merely debilitating), less fertility, and crime. The provinces were culturally conservative, preserving the old ways and refusing to adopt the new religions and methods, having more children, eating better, and being exposed to fewer diseases.
We see that even now, even in technologically advanced societies. There is a difference in the last century in Western society because medical care is better. We have antibiotics. We know about quarantining, vaccination, germ theory, and sanitation. This changes the balance of rural versus urban health, as rural people have more contact with animals and urban people have more hospitals and clinics. But as we saw during the Industrial Revolution and then, the old rules of exposure to more chemicals, filth, and even just plain people still apply. What that means for the future as medical care improves I don't know. But it gives us an idea of what conditions must have been like in Dickens' London and during the plagues, fires, and sieges.
We now see that same pattern in ancient and prehistoric DNA. The cities left little genetic trace, while there was continuity in the remote areas. However, the beliefs and culture of the urban areas grew and spread, while those in the hinterlands gradually disappeared. It has been an odd trade-off for humans.
Archaeologists like to study cities. Geneticists now study isolated populations.
I mentioned that Razib had the Greek geneticist Leonidas-Romanos Davranoglou on for an interview. His lab studies (among other things) isolated populations. On this podcast he talked about the Maniots and the Albanians, two groups with considerable continuity. Both are mountainous and inaccessible, and so mixed with other peoples very little. There are such peoples all over the world, on islands, in mountainous areas, and deep in Amazonia. It is less common in the Mediterranean because trade, travel, and empires. But both groups have uniparental ancestries, both y-chromosome and mtDNA, that go back more centuries than their neighbors. Albania is only about 15% Slav and 15% Roman, the rest being ancient Balkan. In the north the number is even higher.
A very interesting tangent on Maniot ancestery:
"And this lineage we called the Marniot Modal Lineage because it hasn't been found outside Mani. Actually the only few instances where it has been found outside Marni these people have very large autosomal sectors, so they definitely descend their recent migrants from Mani. And by the way, just as a little parenthesis, in our study, we've found only a single example in the rest of the world. This is a real person in the world that has this deep Maniot modal lineage but doesn't have any autosomal heritage from Mani. And this person has now tested and is from an indigenous community in Latin America. And guess what? We did find that they do descend from Mani and we know the exact village and the exact clan. And it's going to be the subject of another paper because the journey of this person's ancestors is absolutely fascinating."(Italics mine. Wild. I'm looking forward to learning what the story behind it is. It's the sort of impossibility found only in speculative fiction.)
Uniparental lineages sometimes have such oddities. There is a a rare but constant presence of a Chinese mtDNA line in Ashkenazi Jews - technically before there were Ashkenazi Jews. The joke is it explains the fondness for Chinese food among NY Jews. I have an oddity myself, and am getting a new DNA sample done that focuses on my maternal lineage, because my U3 shouldn't be in Sweden. We'll see.
When there is a strong founder effect it comes from a severe reduction in population. This might mean a small population migrating to a new area, or it might mean disease, famine, or warfare. Clan-based societies often exhibit these effects, and both of these groups are still clan-based, though this diminished in the 1900s. Many of the clans have founder stories, of a shipwreck from Sicily or a small migration from Cyprus. The DNA reveals that the clan stories that people told about themselves were not true. But the kinship networks turned out to be remarkably accurate.
So for example, a clan might claim a founder from 600 years ago with the particular story attached about where he came from. Testing the people who claim that clan descent in the various villages revealed that they are indeed all related and descended from someone in the 15th century. But there's no indication that that founder came from anywhere outside the province. This seems to accord with how human beings look at themselves, and that we need a story and we pick - or make up - a story that we like, and stick to it. But we actually are pretty good at keeping track of who our important relatives are even when the official records are lost. Clan identification is pretty accurate, despite everything else we lie about. Heck, I went to college at 18 and tried to reinvent myself. Mostly burying some things and highlighting others, but some outright lies. I'm not throwing any stones here.
Some origin stories turn out to be amazingly true, even across centuries. We love those, and start to believe that most of them are based on a kernel of truth, but that's not quite what is showing out. Still, it's remarkable that it happens at all - rumors of a previous people who lived on the land who came from across the sea, or stories of long migrations from the East. BTW according to Davranoglou, the least-accurate origin stories in the Balkans come from the Serbs. Everyone is angry at the DNA researchers for exploding their myths, but the Serbs are sending death threats.
Someone must have done the Scottish clans. I don't know the results. Mine were Wallaces, which was likely a favorite name to steal if you had to get out of town fast and start somewhere else, so I'm not confident of written records. DNA may mislead, but it doesn't lie, though.
