The fall of man

It is well known that in the 5th and 6th centuries of the Common Era the social complexity and economic productivity of the Roman cultural zone underwent a regression. There were two areas in particular where massive transformation occurred. The interior Balkans and Britain were ethnically and religiously changed in totality from their Roman-era state.

Romanian and Vlach dialects today are a testament to the strength of Latin in the interior Balkans, while Albanian attests to indigenous linguistic diversity. But the dominant languages today are Slavic, due to the putative mass migration of tribes under the leadership of the Avars in the 6th and 7th century. These regions also had to be re-Christianized. Something similar happened in Britain, where mass migrations of Germans transformed the language and religion of the whole region.

But we know that genetically the Balkan Slavs and English are actually genetically more like the earlier populations than descendants of migrants. This is not to say that the exogenous genetic material is trivial. It is significant. There was a mass migration of Slavs and Germans. It was just that these did not contribute to the preponderance of the genes.* And yet the language shifted, and the Christian religion faded.

How did this happen?

Late Roman society was defined by specialized economic functions on the production frontier. This was the ancient world’s equivalent of the “just-in-time” economy. In contrast, the Slavic tribes beyond the frontier were arguably even less influenced by Rome than the Germans. These were deeply rustic people. And that was their cultural advantage.

Using a biological analogy, the Late Roman society was like an asexual lineage maximizing short-term gains at the expense of long-term resilience. The “shock” of barbarian incursions in the 5th to 6th centuries totally unraveled the Roman system.

In contrast, small-scaling farming societies organized around clans and tribes, which is how the Slavs were organized, could maintain themselves. Often the Slavs were ruled by non-Slavic groups with origins in the steppes (Avars, Bulgars, etc.), but in the end, the Slavic identity swallowed up their rulers, more or less.

This new setup was successful enough to attract converts from local populations. There is circumstantial evidence that the Anglo-Saxon House of Wessex was actually originally British (look at the early names in the genealogy). They may have been post-Roman British aristocrats who “barbarized.” In Merovingian Francia, Gallo-Roman elites were taking to trousers and aping German Frankish style, but, on the whole the cultural balance was tilted toward the “Romans” rather than the “Germans.” Not so in Britain, it seems.

With all this outlined, it not so surprising that a complex urban society could be culturally assimilated in some ways by a simpler agro-pastoralist lifestyle. The further back you go into the past, the more likely it happened, because the less “robust” the cultural technologies of the urban society were.

* The gene flow into the Balkans was greater proportionally than into Britain. In some cases, more than 50% of the ancestry might be attributable to migrants in the northern and western regions.

The end of the universal Western civilization

During a conversation with Carl Zha (already posted for BrownCast patrons) I inquired about Chinese views of the rest of the world and China’s relationship to other nation-states. I reflected offhand in some ways we don’t know how to deal with this “multi-polar” world, where Asian powers are again relevant after many centuries of being in the shadow of Europe and its offspring. Some of this is also reflected in India, where a rising reactionary conservative nationalism is the odds on favorite to retain power when the tallies are counted for the 2019 election.*

If I live my expected lifespan, I will see the end of the long centuries of the hegemony of Greater Europe. Today the European Union and the USA make up about 30% of the world’s GDP. India and China together are 25%. In 2050 the EU and USA will be 20%. India and China will be 35%. Many projections put Asia as a whole at (excluding the Middle East) at 50% of the world economy in 2050.

If Asian societies maintain current economic momentum, they will have returned to the same proportion of the world economy as they were in ~1800. This date intuitively makes sense. Though the British, under the East India company, were already advancing their way through the subcontinent, in 1800 Manchu ruled Imperial China still retained certain self-confidence, born of a century of economic and demographic expansion.

The 1793 Macartney Embassy saw the Chinese treat the British as they always had. But by this point the dynamic force of history had moved past the Chinese, they just didn’t know it.

The oldest person I have known personally with any great familiarity was my maternal grandfather. He was born in 1896 and died in 1996. It is unlikely that he knew anyone personally who remembered a time before the hegemony of Europeans across the globe. But, it is entirely possible his own grandfather, my own great-great-grandfather, knew people for whom the British as an eternal and dominant force of history was something of a novelty in their youth. My own children will live on after me, likely into the 22nd century. Most of their lives will play out in a very different epoch when it comes to the balance of civilizations.

Of course, one can argue, with some reason, that all civilization from here on out is Western civilization. But I think we need to think back to the late 1990s, and what we believed at the time a post-Western universal civilization would look like. There was an optimism that the end of history would force nations like China to open up politically, while India would match its democratic humanism with robust economic growth. Boris Yeltsin’s Russia was the sometimes helpmate, and sometimes supplicant, of the USA. Though people in India might speak Hindi and eat off thali, while those in China would speak Mandarin and eat with chopsticks, by the end of the 21st century many expected that universal values would lead to a natural federative political state on planet earth. There was no need for top-down world government when capitalism and democratic liberalism spread to all the nation-states on the planet.

Though we should be cautious of swinging in the opposite direction, it does look like the 21st-century will exhibit its own characteristics, not just reflect the dreams of the late 20th.

* I say reactionary because I don’t think Hindu nationalism, like Islamism, is comprehensible without the shock of European modernity. Though these movements present themselves as primal and authentic, they’re really syntheses that came out of the dialectic between the native (Indian) and the colonial (European).

The rise of the steppe (on PBS)

David Anthony’s The Horse, the Wheel, and Language: How Bronze-Age Riders from the Eurasian Steppes Shaped the Modern World is a bit dated, but it’s still a useful read. Papers such as Population genomics of Bronze Age Eurasia and Massive migration from the steppe was a source for Indo-European languages in Europe come out of the tradition that Anthony comes out of. Arguably these thinkers even underestimated the demographic impact of the people from the steppe.

If you are interested in this topic, I think you might find First Horse Warriors: The advent of horse riding changed the course of human history and the genetic makeup of humankind, worth a watch. I think the second half, in particular, will be interesting. Researchers whose names you see only in papers are interviewed. So if you want to put a face to the name, this is your chance.

I would say though that again watching this episode reinforces my point that visual medium is very low density in the information. They had to focus on a few major results and scaffold their visuals around that.

The main issue in the documentary is that researchers still debate the nature of the usage of the horse on the steppe. Anthony and Dorcas Brown have been arguing for an early date of widespread horse domestication, at least as early as 3500 BC. But others suggested a date closer to 2000 BC, around when the light war chariot was invented.

Why the Uyghurs as we didn’t know them didn’t exist until after 1000 AD

The period between 300 AD about 750 AD is sometimes termed the “Buddhist Age.” The reason for this is is that this was the period when Buddhism was established in China, and, was still a force in mainland South Asia. It is also when Buddhism was arguably the dominant religion in much of Central Asia. In fact, Buddhism probably arrived in China mostly through this route, via the city-states of the Tarim basin.

A point of interest for many in the public is that some of these Tarim basin Buddhists looked very “Western.” That is, they had European features and coloring. The reason for this is that their ancestors were the eastern edge of the Indo-European migrations on the steppe. Many of them famously spoke Tocharian languages, an extinct branch of the Indo-European languages. But others spoke Iranian languages. Iranian not in that they came from Iran, but that they were descended from proto-Iranians of the steppe.

A few years ago there was a discussion on this weblog and elsewhere about very recent admixture dates for the western and eastern admixture components in the Uyghurs. That is, after 1000 AD. This struck many as too recent. I think perhaps I have an answer for what happened.

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Rumbles in religion and cultural evolution

A few months ago I posted Society Creates God, God Does Not Create Society, which was a write-up of a paper in Nature, Complex societies precede moralizing gods throughout world history. The study was of interest to me because it seemed to test the hypothesis and argument presented in Big Gods: How Religion Transformed Cooperation and Conflict. Their conclusion using the Seshat historical database was in the negative in relation to the hypothesis. That is, big societies gave rise to big gods, big gods did not seem to give rise to big societies.

Now a different group of researchers, some of them associated with the model of big gods leading to big societies, have shot back with an intense critique of the paper in preprint form, Corrected analyses show that moralizing gods precede complex societies but serious data concerns remain.

There seem to two critical issues that these authors want to highlight: problems in analysis, and problems in the underlying data. In terms of the analysis, the authors suggest that because the Seshat database relies on written evidence it is going to be biased toward more recent dates because writing tends to be found later in social development and complexity. They reanalyzed the data by pushing the emergence of big gods back by a century and found the direction of the effect reverse. In other words, they are saying that the result was not robust. A second issue that impacted the analysis is that the authors of the preprint assert that since so many missing values from preliterate societies were recoded as an absence of big gods what the results are showing is a negative correlation of missing entries with complex societies.

A second broader issue seems to be a suggestion that Seshat itself is riddled with too many errors to be reliable.

As someone deeply interested in the scientific question I don’t have a strong opinion as to what’s going on here (though I am probably a bit skeptical of the idea that Seshat is without much value considering the time and effort I know Peter Turchin and his collaborators have put into it). Feelings seem to be getting heated online, but I’m hoping that open-science will win in the end.

Peter Turchin and Patrick Savage have put up preliminary responses. No doubt there will be more back and forth. But one major improvement over many historical discussions is that this is playing out transparently through data analyses, then the standard “historian here, let me assert my expertise here to shut you down….” (a lot of historians on Twitter behave in a mendacious manner in my opinion, because I often know enough about many historical topics to see exactly how they are laundering their credentials to support sophistry in a manner that is opaque to their trusting audience).

The shadow of the Hun

Short of stature, with a broad chest and a large head; his eyes were small, his beard thin and sprinkled with grey; and he had a flat nose and tanned skin, showing evidence of his origin.

– Jordanes, describing Atilla the Hun

When I was younger (think age 10) I had a period when I read a lot of medieval and “Dark Age” history. Reading about the Huns was pretty scary…they were like the Mongols, but even more, cloaked in legend. I always remember the debates about the physical descriptions of the Huns. On the one hand, it could be plausibly asserted that their descriptions indicated an Asiatic people. But another argument was that the ancient writers were utilizing common tropes to describe barbaric peoples.

Today with DNA we can answer some of these questions with finality. Y-chromosome haplogroups from Hun, Avar and conquering Hungarian period nomadic people of the Carpathian Basin:

Hun, Avar and conquering Hungarian nomadic groups arrived into the Carpathian Basin from the Eurasian Steppes and significantly influenced its political and ethnical landscape. In order to shed light on the genetic affinity of above groups we have determined Y chromosomal haplogroups and autosomal loci, from 49 individuals, supposed to represent military leaders. Haplogroups from the Hun-age are consistent with Xiongnu ancestry of European Huns. Most of the Avar-age individuals carry east Eurasian Y haplogroups typical for modern north-eastern Siberian and Buryat populations and their autosomal loci indicate mostly unmixed Asian characteristics. In contrast the conquering Hungarians seem to be a recently assembled population incorporating pure European, Asian and admixed components.

I was curious about the Hun samples, and the autosomal results. There were only three Huns, but one of them carried haplogroup Q1a2. This is found at highest frequencies in Turkic and Siberian groups. The other individuals were R1b and R1a. R1a is common in Eastern Europe…but the particular variant this Hunnic male carried was of the Z93 branch comon in Central and South Asia, and in particular in places like the Altai.

As far as the autosomal results:

Samples from different archaological cultures and cemeteries showed a remarkable pattern of phenotypic distribution. All Hun and Avar age samples had inherently dark eye/hair colors, DK/701being the only exception (Table 2). Moreover 6/14 Avar age samples were characterized with >0,7 black hair; >0,99 brown eye….

Again, some historians have argued that the tropes that emerged to describe the Sarmatians and Scythians were recycled for the Huns. But we know what these groups looked like because we have ancient DNA from them: they were clearly West Eurasian people, with western populations heavily Europeanized. It is clear from these results that the Huns and Avars were physically reflective of their East Asian origin. The ancient authors describing them in exotic terms were describing reality, not a metaphor.

I look forward to discovering whether other “metaphors” of the descriptions of ancient peoples turn out to be literal and serious as well.

Why Indian forms dominated Chinese forms in mainland Southeast Asia


On Twitter Peter Turchin had a question in response to me tweeting a new preprint on bioRxiv:


This was my impression too until a few years ago, but the genetic evidence does point to gene-flow. Here are two recent posts from me, Likely Male-Mediated Indianization In Southeast Asia and Indic Civilization Came To Southeast Asia Because Indian People Came To Southeast Asia. Lots Of Them.

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Random and inevitable forces in world history: the 6th century

In Science Anne Gibbons reports on new ice-core evidence for why the middle of the 6th century A.D. was so difficult in much of Europe:

Historians have long known that the middle of the sixth century was a dark hour in what used to be called the Dark Ages, but the source of the mysterious clouds has long been a puzzle. Now, an ultraprecise analysis of ice from a Swiss glacier by a team led by McCormick and glaciologist Paul Mayewski at the Climate Change Institute of The University of Maine (UM) in Orono has fingered a culprit. At a workshop at Harvard this week, the team reported that a cataclysmic volcanic eruption in Iceland spewed ash across the Northern Hemisphere early in 536. Two other massive eruptions followed, in 540 and 547. The repeated blows, followed by plague, plunged Europe into economic stagnation that lasted until 640, when another signal in the ice—a spike in airborne lead—marks a resurgence of silver mining, as the team reports in Antiquity this week.

Kyle Harper, author of the excellent The Fate of Rome: Climate, Disease, and the End of an Empire, is quoted in the piece. It’s curious to me to observe the stochastic and correlated events in this particular story.

I assume that volcanic mega-eruptions occur in a pattern defined by a Poisson distribution. That is, they are rare and random events. One thing about the Poisson distribution is that the events tend to cluster together more than human intuition would predict based on what we think might occur when we hear “random events.” Those with more paleoclimate knowledge that I can evaluate this, but it seems that massive eruptions that occurring so close in time are going to be rare indeed, but, they will happen now and then.

That’s the random part. The outbreak of plague is probably less random. In Europe, the plague faded in the early modern period. Though people disagree about the reasons, modern developed societies where people are more well-fed are probably less susceptible to it (as well as low-density hunter-gatherer or pastoralist populations). As Peter Turchin has pointed out only one sitting European monarch died during the Black Death of the bubonic plague, even as 30-60% of the local population succumbed. It seems likely that extremely difficult conditions for agriculture, and the consequent malnutrition, made the spread of plague through vulnerable populations much more likely.

A major consequence of the calamities of the mid-6th century is the reconquest of the West Roman Empire under the push from Justinian and his heirs lost steam. Unlike in China, the Roman system was never recreated in full. Many explanations have to do with the violence of the Gothic Wars, or the inability of East Roman power to expand west while dealing with a more vigorous Persia to the east. We can’t rerun the experiment, but the above volcanic eruptions suggest that the likelihood of total reconquest took a major hit because of an event that was not inevitable.

Remember that the Roman state recovered by near total unwinding in the middle of the 3rd century.

Though we will never resolve the issue of whether the fall and collapse of the Roman Empire was inevitable and its reassembly impossible, by looking in totality at volcanic events and seeing how it correlates with state-formation or collapse, and social complexity, we may get a sense of the nature of the balance of endogenous cyclical forces and exogenous random shocks in the rise and fall of polities. By endogenous cyclical forces, I’m referring here to social cohesion and elite unity, which over time degrades and decays. As states and societies fracture and a new cycle of integration begins anew. I suspect that the exogenous shocks occur periodically, but that if they slam a society at its peak, then the social structure may be able to absorb the shock. In contrast, societies under stress collapse due to unexpected perturbations.

The coming genetic invasion of history, and the rage to come

About ten years ago I reviewed Bryan Sykes’ book Saxons, Vikings, and Celts: The Genetic Roots of Britain and Ireland. It was what it was, a product of the Y/mtDNA era. Therefore, there were a fair amount of conclusions which in hindsight turn out to be wrong. Sykes, and other genetic historians, such as Stephen Oppenheimer, have annoyed historians for years with their genetic imperialism. More frequently, genetic research has been an accent or inflection on historical work. Peter Heather has integrated some genetic results in his earlier books, though you can ignore those and still obtain the general conclusions.

The recent work on near antiquity is a hint that that is going to be blown apart. Ancient DNA in the historical period has been a slow simmer for a while now. The reason is simple: ancient DNA returns more on the investment for prehistory, where there aren’t historical documents. Until recently ancient DNA techniques were expensive in a variety of ways. The industrial process described in Who We Are and How We Got There is going to change that.

In the near future, a large number of projects are going to surface which test hypotheses and conjectures offered by historians.

You would think that testing hypotheses, generally with demographic predictions, would be something that historians would welcome. The problem is that the test will mean some scholars are going to turn out to be wrong. People who spent decades building up a particular model or understanding of the past are going to have that torn away from them.

The normal human reaction is to get defensive. But the problem is that many historians are not well trained in genetic methods. In fact, many geneticists are not well trained in the abstruse statistical methods developed by scholars in ancient DNA.

We’ve seen some of the same from archaeologists. But archaeologists had models which were, to be frank, more speculative than those historians cling to. Even if a particular historical model may be wrong, it is likely there are reasonable grounds to have held onto to that position. If ancient DNA falsifies it the reaction will be even more strident I suspect.

Of course, geneticists need the help of historians. So when the bad feelings clear I think the synthesis will get us to a better understanding of the past.

The new post-genetic paradigm will come

Oftentimes the domain on which a technical framework is applied matters a great deal. Imagine, if you will, an explicit statistical test for a phylogenetic relationship between a set of extant populations, whereby one infers a group of ancestral populations. If the genus is Drosophila, it’s academic. Interesting, but academic. If the genus is Homo, then it gets complicated.

People care a great deal about the historical inferences made from human population genomic datasets. I say genomic, and not genetic, because the last ten years with genome-wide analyses and ancient DNA is very different from what we saw in the late 20th century and aughts. The definitive granularity is such that population genomics has touched upon very sensitive and precious issues, both in a scholarly and non-scholarly context.

A lot of the time I have my head down reading supplements where the statistical methods are. The reality is that this sort of science is cutting edge, and there are always later revisions. Usually you can see where those revisions might come from if you look at the detailed methods and conclusions that are found in the supplements. Also, you will find that that is where you see the limitations, and the reasons that the authors chose particular parameters.

To give you a sense of what I’m talking about, consider 2016’s Genomic insights into the origin of farming in the ancient Near East. The paper proper is 24 pages. But the supplemental text is 148 pages. There is a lot of interesting stuff in there, but I would just jump to page 125 and read the whole section there and down to the end. The method portion is important because you always need to take number values in results with a grain of salt. You see for example later work which refines fractions significantly when it comes to estimating admixture between a finite set of putative populations. And the last section seems likely to become a paper in and of itself at some point

But that doesn’t mean that the genetic inferences are not robust and come out of a vacuum. In the details the phylogenetic models being tested are going to be wrong on many particulars, but in relation to hypotheses being tested they are often entirely sufficient to reject to accept.

For example, there was long the idea that the Basque people of the western trans-Pyrenees region of Spain and France descended from pre-farming Europeans, and therefore the Basque language, which is an isolate, might have local roots which went back to the Pleistocene. Today, ancient DNA along with explicit testing of various phylogenetic scenarios makes it clear that the largest fraction of Basque ancestry derives from “Early European Farmers,” who represent a demographic pulse which radiated out of the Eastern Mediterranean and reached Spain 7,500 years ago. Of course Basques do have local hunter-gatherer ancestry, but these Mesolithic peoples themselves were the last in a sequence of very distinctive populations in Pleistocene Europe. Finally, Basques do have admixture from Indo-European peoples, just less than other people in Iberia.

Of course, genetics can’t tell us about languages. Using linguistic labels in population genetic papers is to some extent a lexical convenience, but it is also one we use because of the constellation of information we have. The last major demographic pulse into Iberia is associated with an ancestry which derives from Central Eurasia. This ancestry is copious in Northern Europe, but is also found in South Asia, and ancient DNA suggests its expansion occurred between 5,000 and 3,500 years ago. It also happens that the Indo-European languages are spoken in both India and Europe. The natural inference then is to make an association between this language family, and this demographic pulse.

Some observers note discordance between estimated fractions from paper to paper, but don’t seem to understand that the point isn’t to estimate fractions of ancestry as ends in and of themselves, but to estimate fractions of ancestry to expose and highlight demographic change (or lack thereof). We can say with a very high degree of certainty that the period between 3000 and 2000 BC witnessed massive demographic change in Northern Europe. Somewhat later there was a similar change in Southern Europe, but more demographically modest. These are simple facts.

There are some scholars, frankly often archaeologists, who dismiss the relevance of the genetic findings. But anyone who has read archaeology knows that there are many cases where researchers see demographic continuity, and posit in situ cultural evolution, where it is just as possible that a new people arrived. The reason ancient DNA has revolutionized our understanding of prehistory isn’t because it has brought us new knowledge, it has foregrounded old and buried knowledge. The knowledge being that migration matters.

But genetics is only a skeleton. A framework. True flesh on the bones of the story needs the input of archaeologists, linguistics, and other scholars. In Who We Are and How We Got Here David Reich expresses his ambition to construct a historical genetic atlas of the world. But that atlas will be all the poorer without the input from other fields besides genetics. Many archaeologists have gotten on board with genetics as a tool, but the reality is that there needs to occur the rejection of some theories precious to some scholars if there is going to be total buy-in. Eventually that will happen, and a new synthesis will arise.