The Canaanites walk among us: ancient DNA edition

Ancient DNA from here to there:

Ancient DNA has illuminated many things, but there is a logic as to what topics and questions it tackles. The focus on northern Eurasia is clearly a function of the probability of preservation, though techniques of extraction are getting better and better. I can’t imagine how we’d ever get a sample out of a moist tropical environment, but I won’t be surprised if something is obtained from a cave in southern Africa or high in the Tibesti in the near future.

But another parameter is time since the demographic events in question. Too ancient, and the probability of success is too low(ok, time is a parameter in much of science!). It seems plausible that in idealized circumstances we’re going to push beyond the one million year barrier. And yet too recent is also a problem (or not a problem!). For humans and even non-humans we have lots of corroboration about questions we might ask about the recent past. You could use “ancient DNA” to trace the migration of Mormons across the Intermontane West, but why would you?

So you see the earliest ancient DNA work on humans was biased toward testing models about gene flow and ancestry tens of thousands of years in the past, between modern humans and archaic lineages. Obviously we don’t have oral history or written texts from this period, and archaeology will only get us so far.

More recently the time depth has been getting shallower and shallower. Both David Reich and Eske Willerslev’s work on European prehistory is liminally historical. By this, I mean that what is prehistory in Europe is a historical period in the Near East. We may not have written records from the Corded Ware or Bell Beaker cultures, but we do have plenty of them from contemporaneous Near Eastern groups.

The Cauldron of Peoples:

There are still questions to be asked about European prehistory, but the gaps are getting narrower and narrower. Scholars are finally devoting resources to other regions of the world. Last year Iosif Lazaridis’ The genetic structure of the world’s first farmers finally opened up the box that was the prehistory of the Near East. This was important, because much of prehistory and history began in the Near East. Farmers from this region seem to have moved into Europe, South Asia, Central Eurasia, and Africa. To understand the population histories of these areas one needs to understand the population history of the Near East.

What Lazaridis et al. found this that there were at least two major groups of very genetically distinct Near Eastern farmers at the dawn of agriculture. Once group faced the eastern Mediterranean, while the other seems to have flourished on the slopes of the Zagros. Western and eastern farmers respectively. It is important to note that these two groups were very genetically distinct. If we sampled these two groups of farmers, who faced each other across northern Mesopotamia, in any modern population survey we’d assume that the genetic distance meant that they were sampled from different continents or very distant regions of Eurasia.

This finding suggest that the clinal patterns of variation in much of today’s world may be a consequence of massive population admixture between groups which had heretofore exhibited deep population structure. Why such deep structure existed and persisted is an interesting question, but at this point it is important to note descriptively that the past 10,000 years have seen a massive reduction of this structure due to gene flow between populations.

In the Near East Lazaridis et al. found that there was significant reciprocal gene flow between the western and eastern regions of the Near East after the emergence of farming, down to the historical period. This is one reason that estimates of “farmer” ancestry in modern Europeans always gave very low estimates: the reference populations no longer existed in unmixed form in the Near East. The peoples who brought agriculture to Southern Europe were related exclusively to the western farmers of the Near East, a population which no longer exists in unmixed form in that region of the world (ergo, among modern groups Sardinians are the closest proxies we have).

The Age of Bronze:

But there is much that occurred after prehistory in the Near East. We know this because we have extensive records going back 4,500 years, and even earlier. And though put into written form in the first millennium before Christ, the Hebrew Bible also records the deeds and names of people who have come and gone well before the Classical Age.

A new preprint on biorxiv sheds some light on a critical transitory period, Continuity and admixture in the last five millennia of Levantine history from ancient Canaanite and present-day Lebanese genome sequences:

The Canaanites inhabited the Levant region during the Bronze Age and established a culture which became influential in the Near East and beyond. However, the Canaanites, unlike most other ancient Near Easterners of this period, left few surviving textual records and thus their origin and relationship to ancient and present-day populations remain unclear. In this study, we sequenced five whole-genomes from ~3,700-year-old individuals from the city of Sidon, a major Canaanite city-state on the Eastern Mediterranean coast. We also sequenced the genomes of 99 individuals from present-day Lebanon to catalogue modern Levantine genetic diversity. We find that a Bronze Age Canaanite-related ancestry was widespread in the region, shared among urban populations inhabiting the coast (Sidon) and inland populations (Jordan) who likely lived in farming societies or were pastoral nomads. This Canaanite-related ancestry derived from mixture between local Neolithic populations and eastern migrants genetically related to Chalcolithic Iranians. We estimate, using linkage-disequilibrium decay patterns, that admixture occurred 6,600-3,550 years ago, coinciding with massive population movements in the mid-Holocene triggered by aridification ~4,200 years ago. We show that present-day Lebanese derive most of their ancestry from a Canaanite-related population, which therefore implies substantial genetic continuity in the Levant since at least the Bronze Age. In addition, we find Eurasian ancestry in the Lebanese not present in Bronze Age or earlier Levantines. We estimate this Eurasian ancestry arrived in the Levant around 3,750-2,170 years ago during a period of successive conquests by distant populations such as the Persians and Macedonians.

The period between 1700 and 1800 BCE in the Near East saw many changes and was a sort of nexus. Sumer had fallen, the Hittites had not emerged as a superpower, while Egypt was not heavily involve in the game of kings as of yet. The system of international relationships described in Brotherhood of Kings had not crystallized. That was for the late Bronze Age.

But some of the pieces we were to recognize were already in place. An Amorite Babylon under Hammurabi established the contours of the culture and polity we’d recognize down to the Persian conquest. In Egypt the Middle Kingdom was going into decline, and the Hyksos interregnum would give rise to the New Kingdom, which would become a major player in the Levant (and probably is the model for much of the Egypt we see described in the Bible).

The admixture plot above reflects the five individuals from Sidon dating to about ~1750 BCE. They are about a 50:50 mix of western and eastern farmer. Though they seem to be genetically rather similar to modern Lebanese (the authors sampled Lebanese Christians in particular), there have been some changes between the Bronze Age and the modern period. In particular, a genetic component that seems to be related to the Eurasian steppe is present in modern Lebanese. Explicit admixture estimates give a range of 5-10% mixing into a ~90-95% Bronze Age ancestral background.

This seems to establish basic continuity between the Bronze Age and the modern period. Totally unsurprising. Remember that Italy exhibits deep population structure that dates back to at least 2,000 years ago, and probably earlier. It is likely that much of the same applies to the Near East. Though looking at Muslim populations one can see minor and non-trivial contributions of populations which moved in after Islam (Sub-Saharan and East Asia segments are clear signs of slavery impacting Muslims that would not apply to ethno-religious minorities), most of the ancestry broadly is deeply rooted back to antiquity.

Because of sampling issues one can’t estimate admixture between eastern and western farmers just from looking at ancient DNA transects. We don’t have the density that we have in Europe (yet). So the authors used a more classic inference technique looking at decays of linkage disequilibrium in the genome. In short you can see how many generations that a pulse admixture between two populations occurred by looking at correlations of variants across the genome. The authors arrive at the intervals above, and in particular focus on the period that seems to overlap with the rise and fall of the empire of Sargon of Akkad and correlated with a climatic disruption.

I suspect they are wrong here. First, it seems pretty clear to me that LD based admixtures assuming a pulse event have a bias toward underestimating values. There are theoretical reasons for this. So usually I pad the mid-point value across the interval on these estimates.

One thing that ancient DNA has told us is that often the less complex the society, the more demographic turnover you have. All things equal then we would expect turnover to be an older event, as simple societies are succeeded by complex ones. The succession of complex societies by other complex societies is often less disruptive for the masses because this transformation is more a matter of elite replacement.

By ~2200 BCE the Near East was already quite complex. I believe that the massive western-eastern farmer admixture occurred between 3600 and 3100 BCE, during the Uruk Expansion. The evidence of lower Mesopotamian influence and demographic settlement in places as far afield as Anatolia, the Caucasus, and Syria, are well attested from the archaeology of this period. This was was a time when a very complex and sophisticated civilization emerged almost de novo across much of the Near East. I believe that a prehistoric expansion of Sumerian civilization mediated the merging of eastern and western farmers, though some of the mixing pre-dates and post-dates the Uruk Expansion and collapse (e.g., the movement of western farmer ancestry into Mesopotamia seems certain to have occurred through the arrival of groups like the Amorites).

Additionally, buried in this preprint is evidence of major Y chromosomal turnover. We’ve seen this  before. The prominence of haplogroup J in Bronze Age and modern Levantines seems to be due to eastern farmer migration. In fact, adding haplogroup J and R together we get the inference that more than half the paternal lineages of Lebanese today are not from western farmers native to the area.

Beyond the Bronze Age:

What about the second ancestral component? Drilling down on the Y chromosomes of the Levant, R1b seems to far outnumber R1a, though the R1a clades are all of the Asian/Scythian Z-93 branch which is dominant in Central Asia and the Levant. The R1a may have come with the Persians, but in region of the western Levant for several hundred years after the period of the Bronze Age Sidon samples there was a state, the Mitanni, which clearly had an Indo-Aryan ruling class.

An Aegean influence occurred multiple times. First, at the end of the Bronze Age many of the “Sea Peoples” were clearly of Aegean origin, and so may have brought steppe-like ancestry. Second, there was the long period under Hellenistic and Roman rule, when Greek and non-Greek ethnic identity existed side by side, and movement occurred in both directions. I think only ancient DNA will answer this question, and it may be that there were multiple post-Bronze Age inputs of genes which shaped modern Levantines.

After Babel:

The curious thing that many of these studies are telling us is two-fold:

  1. Most of the population genetic structure we see around us dates to the Bronze Age, on the borderlands between history and prehistory. I think we can start to set this as a strong prior. It holds true for the Near East, Africa, South Asia, Japan and Southeast Asia. We’ll see about core East Asia, but I think probably it is true there too.
  2. Selection has continued, so that alleles for lactose tolerance and lighter skin have changed in frequency even since that period. The derived allele for SLC45A2 is found at about 2/3 frequency in modern Lebanon, but was absent in these five Sidonians. Though the sample size is small, this was somewhat surprising, and suggests that they were a swarthier people than modern Lebanese.

Addendum: I have said little here about Afro-Asiatic languages, as I don’t know enough about this topic.

At an inflection point of archaeology and genetics

People always ask me what to read in relation to the field of historical population genetics. In the 2000s there were a series of books which focused on the mtDNA and Y results from modern phylogeographic analysis. Journey of Man, Seven Daughters of Eve, The Real Eve, and Mapping Human History. But there hasn’t been much equivalent in the 2010s.

Why? I think part of the issue is that the rate of change has been so fast that scholars and journalists haven’t been able to keep up. And, the change is happening right now, so it would likely mean that any book written over a year would be moderately out of date by publication.

I noticed today that Jean Manco has an updated and revised version of her book, Ancestral Journeys: The Peopling of Europe from the First Venturers to the Vikings. This was needed, because the original book was written before some major recent findings, though after some preliminary ones. As Manco has observed herself it was feasible to replace speculations with facts.

Since it seems likely that George R. R. Martin’s next book will be published before David Reich’s, I think that’s all you got. Any suggestions would be welcome.

As for the flip side for history that might be useful to understanding the genetics results, J. M. Roberts The History of the World is the best cliff notes I can think of. It’s obviously a high level survey, but frankly that would improve the interpretation I see in some papers. The fact that much of the history has no contemporary relevance is pretty unimportant, since you want to focus on the older stuff, which is where ancient DNA really shows its metal.

At some point ancient DNA will start to exhibit diminishing returns. Then the long hard slog of interpretation and synthesis will have to begin in earnest.

The eternal Axial Age

As I have noted before one of the most interesting aspects of ancient Greek history is that in many ways the socio-political identities and outlook of the Hellenic people before and after the Bronze Age were probably as distinct as that between hunter-gatherers and agriculturalists. That is, the citadel culture of the Mycenaeans was constructed out of recognizable elements. Take one dollop Near Eastern autocracy, add a dash of semi-civilized barbarian warlord, and finish off with the tincture of brutalist post-Minoan aesthetic, and you have the pirate kings of Achaea, who so plagued the kings of the Hittites and later transformed themselves into the “Sea Peoples.”

The story of what happened after the end of the Bronze Age is somewhat well known to us, because the roots of our civilizations are clear in the ideas which emerged in the period between 1000 BCE and 0 CE. The basis of the institutional religions which we see around us date to the Axial Age. Judaism, Christianity, Islam, Hinduism, and arguably Daoism, Confucianism, Buddhism and Zoroastrianism, either arose or ripened in the one thousand years after the birth of Christ, but from a naturalistic perspective the bases of these traditions are present in the early Iron Age. To be concrete about what I’m getting at, Judaism over its history truly takes shape in the centuries leading up to, and subsequent to, the compilation of the Babylonian Talmud. But the disparate threads of Rabbinical Judaism were already there in the centuries before Christ; they were simply synthesized and extended later on.

Much the same can be said about science. On the one hand, a narrow view of science is that it is the cultural product of a group of individuals who began collectively exploring aspects of the natural world in the 17th century. Eventually this contingent cultural enterprise spread across the whole world. But the roots of the scientific enterprise can also be seen in the Pre-Socratic philosophies. It was already there 2,500 years ago. But the victory of Platonism, and later the rise of Hellenistic ethical systems, and finally the ideological uniformity imposed by Christianity, dampened the efflorescence of heterodox speculations which flourished for the few centuries around 450 BCE. The steam went out of the scientific enterprise, and it never truly became science as we understand it in the modern world. But pieces of it that came together later on were familiar to us of old.

And then there are the political innovations. The Greeks gave us all their different varieties; democracy, oligarchy, the mixed monarchy-oligarchy of Sparta. The Romans had their republic, and even during the imperial period rejected the institution of ‘kinship,’ though all the powers of a king were eventually accrued to the emperors.

But political debate existed outside of Greece and Rome. In China political and ethical philosophy were intertwined, the tension between Legalism and Confucianism would continue down through the ages after the official ascendancy of the latter during the Former Han. In India there was a variety of forms of governance characterized by differing levels of centrality before the conquest of the Mauryas set the horizons and template for much of the rest of South Asian history.

Democracy and republics faded. Republican governments eventually made periodic revivals. During the period of the American Revolution many were skeptical of the idea of such a geographically expansive state such as the United States being able to maintain a republican form of governance. The shift toward a more democratic self-identity in the early 19th century with the rise of Jacksonian populism was even more shocking, because for much of history democracy was seen as a failed Greek experiment which often devolved into illiberal mob rule.

I recall 15 years ago Steven Pinker observing that one reason philosophy has made little progress is that what one could not make progress in was consigned to philosophy, while the natural and social sciences waxed in their ability to model and explain the world around us. This is uncharitable to philosophy in many ways, but it gets at something real: we haven’t pushed much further beyond the Greeks on foundational questions. Similarly, Islam is the last major religion to have emerged, and the theology of Christian churches and the metaphysics of Buddhism and Hinduism are all one to two thousand years old. Instead of progress we’ve seen shifts back and forth in fashion. Reworking of templates, not the creation of new things.

Over the past few centuries we have witnessed something different than this. The birth of the modern. The explosion of democracy and liberalism, and economic well being through massive gains to welfare and well being to the non-elites. Between 1800 and 1970 the wage gap between the skilled and unskilled in Western societies shrank. Seen from the first half of the 1960s the future was shiny, infectious disease was going to be unknown, and robots would allow us a life of leisure.

Though we do have iPhones and other shiny devices, and nerds like me can consume lots information on the web, things have not quite worked out in exactly the way predicted. Yes, China and much of the developing world has improved in terms of vital statistics. And it looks like space commerce may finally arrive in the next decade. But we do not have a Mars colony in 2017, let alone a Moon colony.

Economic productivity combined with a demographic transition mean that extreme deprivation is slowly being strangled. But inequality flourishes, and the wage gap between the skilled and unskilled began to increase after 1970 in the developed world. Whereas at one point the Whiggish perception that history was progressive, and that it would end in some quasi-utopian terminus, was self-evident, today many are not as certain. The unipolar geopolitics of the 1990s has given way to a new farcical world of the “Great Game,” while secular Arab nationalism has faded to irrelevance in the face of a resurgence Islamic identity.

History does not move in cycles where the future reenacts the past. But much of the modular furniture of existence seems to be 2,000 years old. The Salafi movements the world over are fundamentally products of modernity, or the reaction to various elements of European modernity. Their roots pre-date the 20th century, and go back to revivals in the Arabian peninsula in the 18th century which parallel a reconstruction of self conscious orthodox Islam in India as the Mughal order was collapsing. But ultimately they are refurbishing the furniture put together by Ibn Hanbal in the 9th century, who himself might have been comfortable among Judaean Zealots. The Taliban are simply the Maccabees of our age.

From an American perspective the reality, the necessity, of the spread of democracy and the expansion of liberalism seem self-evident. Inevitable. Along with technology and science, it all seemed to hang together. In the 1990s the future was arriving as scheduled.

In 2017 the Russian experiment with Western democratic forms has not turned out how we wanted. Though China is economically liberal, it is not democratic. The global capitalist elite were as surprised as everyone else by 2008, and in the wake of that shock they have persuaded themselves that there is no need for a fundamental rethink of the institutions that they’ve developed over the past 70 years since the Bretton Woods Agreement.

As the Western economic elite continues to persist in denial, the cultural elite has been making a broad push to sweep post-1960s social liberalism throughout the world. This, all the while that Western societies have been demographically stagnant, and Western economic power has been declining in relative terms.

We are in the late stages of the long 20th century. The institutions and mores of the post-World War II are still with us, like Zeitgeist zombies. But the combination of global capitalism, individualism, democratic values always constrained by oligarchic preferences, and the universal acid of Critical Theory infused identity politics, does not hang together in a robust fashion. In most of the world if people have to pick between their ‘sexual identity’ and their ‘religious identity’, I think it will be the latter (assuming they concede that a sexual identity is a thing). In the early 20th century Marxists had to confront the fact that internationalism was not capable of overcoming nationalism. In the 21st century the identity politics of individual self-actualization and self-definition will likely confront 2,000 year old identities.

Ideologues dream of final victories. Of ideologies sweep through the world, from sea to sea. Global Communism. A world-wide capitalist order defined by free trade and free movement of peoples. China and India converting to Christianity and finally ending the civilizational conflict between Christendom and Islam, as Muslim MENA is constricted between Christian Europe, Africa, and Asia.

But pluralism has defined the last few thousand years. The final victory has been elusive. The old ideologies and religions do not die, they evolve, they reinvent, they repurpose. The stories are different in each age, but they live in a shared universe of characters who also repeat similar plot elements.

The second century BC was a strange time for the Roman republic. It was an empire in all but name. The ancient enemy Carthage was no more. But destitution was also coming to some of the Roman people. This resulted in reformers attempting to right the ship of state. The brothers Gracchi attempted to help the plight of the Roman poor with redistribution.  Marcus Livius Drusus expanded the franchise to non-Roman Italians. Political redistribution if you will. Gaius Marius began as a necessary general, but ended as a chaotic autocrat. The social cohesion of the Roman republic was breaking down. Faction began to dominate all of public life.

Into situation stepped Sulla. Sulla is not a contingent man. Sulla is a type. A reaction, usually a vain and futile attempt to hold the past together, and push it into the future, by brutal means. Sulla arises when social elites lose faith in the present, and attempt to recreate institutions from an idealized past.

Sulla is efficient. Cruel, but certain in his rightness. Sulla is not a clown. He is not narcissistic, for Sulla does have ideals, even if you hold that those ideals are cruel or callous. Sulla is a piece of furniture, found in many places at many times. The United States of America has not seen Sulla yet. I believe it will.

Dramatization of the arrival of the Beaker people

Normally a conference or a talk related to the Bell Beakers and their spread across Western Europe would involve a few presentation slides with pictures of beakers and shaded maps, and result in the production of a scholarly compendium such as The Bell Beaker Transition in Europe: Mobility and local evolution during the 3rd millennium BC. From the description on Amazon in relation to this book:

Could the circulation of objects or ideas and the mobility of artisans explain the unprecedented uniformity of the material culture observed throughout the whole of Europe? The 17 papers presented here offer a range of new and different perspectives on the Beaker phenomenon across Europe. The focus is not on Bell Beaker pottery but on social groups (craft specialists, warriors, chiefs, extended or nuclear families), using technological studies and physical anthropology to understand mobility patterns during the 3rd millennium BC. Chronological evolution is used to reconstruct the rhythm of Bell Beaker diffusion and the environmental background that could explain this mobility and the socioeconomic changes observed during this period of transition toward Bronze Age societies. The chapters are mainly organized geographically, covering Eastern Europe, the Mediterranean shores and the Atlantic coast of the Iberian Peninsula, includes some areas that are traditionally studied and well known, such as France, the British Isles or Central Europe, but also others that have so far been considered peripheral, such as Norway, Denmark or Galicia. This journey not only offers a complex and diverse image of Bell Beaker societies but also of a supra-regional structure that articulated a new type of society on an unprecedented scale.

Pretty dry. But thankfully in lieu of PowerPoint slides some researchers have gotten more clever, and in light of new findings I present a short film depicting the Bell Beaker arrival in what became Britain. Pretty quick turnaround, no?

Related: The Bronze Age Demographic Transformation Of Britain.

When conquered pre-Greece took captive her rude Hellene conqueror

When I was a child in the 1980s I was captivated by Michael Wood’s documentary In Search of the Trojan War (he also wrote a book with the same name). I had read a fair amount of Greek mythology, prose translations of the Iliad, as well as ancient history. The contrast between the Classical Greeks and the strangeness of their mythology was always something that on the surface of my mind. The reality that Bronze Age Greeks were very different from Classical Greeks resolved this issue to some extent, as the mythos no doubt drew from the alien world of the former.

Though Classical Greeks were very different from us (e.g., slavery), to some extent Western civilization began with them, and they are very familiar to us for this reason. Rebecca Goldstein’s Plato at the Googleplex was predicated on the thesis that the ancient Greek philosopher had something to tell us, and that if he was alive today he would be a prominent public speaker.

I’m going to dodge the issue of Julian Jaynes’ bicameral mind, and just assert that people of the Bronze Age were fundamentally different from us in a way Plato was not. And that difference is preserved in aspects of Greek mythology. Though it is fashionable, and correct, to assert that Homer’s world was not that of Mycenaeans, but the barbarian period of the Greek Dark Age, it is not entirely true. Homer clearly preserved traditions where citadels such as Mycenae and Pylos were preeminent. Details such as the boar’s tusk helmets are also present in the Iliad. His corpus of oral history clearly preserved some ancient folkways which had fallen out of favor.

But aesthetic details or geopolitics are not what struck me about Greek mythology, but events such as the sacrifice of Iphigenia. Like Abraham’s near sacrifice of his son, this plot element seems to moderns cruel, barbaric, and unthinking. And though the Classical Greeks did not have our conception of human rights, they had turned against human sacrifice (and the Romans suppressed the practice when they conquered the Celts) on the whole. But it seems to have occurred in earlier periods.

The rupture between the world of the Classical Greeks and the strange edifices of Mycenaean Greece were such that scholars were shocked that the Linear B tablets of the Bronze Age were written in Greek when they were finally deciphered. In fact many of the names and deities on these tablets would be familiar to us today; the name Alexander and the goddess Athena are both attested to in Mycenaean tablets.

Preceding the Mycenaeans, who  emerge in the period between 1400-1600 BCE, are the Minoans, who seem to have developed organically in the Aegean in the 3rd millennium. This culture had relations with Egypt and the Near East, their own system of writing, and deeply influenced the motifs of the successor Mycenaean Greek civilization. The aesthetic similarities between Mycenaeans and Minoans is one reason that many were surprised that the former were Greek, because the Minoan language was likely not.

Mycenaean civilization seems to have been a highly militarized and stratified society. There is a reason that this is sometimes referred to as the “age of citadels.” Allusions to the Greeks, or Achaeans, in the diplomatic missives of the Egyptians and Hittites suggests that the lords of the Hellenes were reaver kings. In 1177 B.C. Eric Cline repeats the contention that a fair portion of the “sea peoples” who ravaged Egypt in the late Bronze Age were actually Greeks.

So when did these Greeks arrive on the shores of Hellas? In The Coming of the Greeks Robert Drews argued that the Greeks were part of a broader movement of mobile charioteers who toppled antique polities and turned them into their own. The Hittites and Mitanni were two examples of Indo-European ruling elites who took over a much more advanced civilizational superstructure. While the Hittites and other Indo-Europeans, such as the Luwians and Armenians, slowly absorbed the non-Indo-European substrate of Anatolia, the Indo-Aryan Mitanni elite were linguistically absorbed by their non-Indo-European Hurrian subjects. Indo-Aryan elements persisted only their names, their gods, and tellingly, in a treatise on training horses for charioteers.

Drews’ thesis is that the Greek language percolated down from the warlords of the citadels and their retinues over the Bronze Age, with the relics who did not speak Greek persisting into the Classical period as the Pelasgians. Set against this is the thesis of Colin Renfrew that Greek was one of the first Indo-European languages, as Indo-European languages began in Anatolia.

The most recent genetic data suggest to me that both theses are likely to be wrong. The data are presented in two preprints The Population Genomics Of Archaeological Transition In West Iberia and The Genomic History Of Southeastern Europe. The two papers cover lots of different topics. But I want to focus on one aspect: gene flow from steppe populations into Southern Europe.

We know that in the centuries after 2900 BCE there was a massive eruption of individuals from the steppe fringe of Eastern Europe, and Northern Europe from Ireland to to Poland was genetically transformed. Though there was some assimilation of indigenous elements, it looks to be that the majority element in Northern Europe were descended from migrants.

For various reasons this was always less plausible for Southern Europe. The first reason is that Southern Europeans shared a lot of genetic similarities to Sardinians, who resembled Neolithic farmers. Admixture models generally suggested that in the peninsulas of Southern Europe the steppe-like ancestry was the minority component, not the majority, as was the case in Northern Europe.

These data confirm it. The Bronze Age in Portugal saw a shift toward steppe-inflected populations, but it was not a large shift. There seems to have been later gene flow too. But by and large the Iberian populations exhibit some continuity with late Neolithic populations.  This is not the case in Northern Europe.

In The Genomic History Of Southeastern Europe the authors note that steppe-like ancestry could be found sporadically during early periods, but that there was a notable increase in the Bronze Age, and later individuals in the Bronze Age had a higher fraction. Nevertheless, by and large it looks as if the steppe-like gene flow in the southerly Balkans (focusing on Bulgarian samples) was modest in comparison to the northern regions of Europe. Unfortunately I do not see any Greece Bronze Age samples, but it seems likely that steppe-like influence came into these groups after they arrived in Bulgaria, which is more northerly.

Down to the present day a non-Indo-European language, Basque, is spoken in Spain. Paleo-Sardinian survived down to the Common Era, and it too was not Indo-European. Similarly, non-Indo-European Pelasgian communities continued down to the period of city-states in Greece.

These long periods of coexistence point to the demographic equality (or even superiority) of the non-Indo-European populations. The dry climate of the Mediterranean peninsulas are not as suitable for cattle based agro-pastoralism. This may have limited the spread and dominance of Indo-Europeans. Additionally, the Mediterranean peninsulas were likely touched by Indo-European migrations relatively late. Much of the early zeal for expansion may have already dissipated by them. The high frequency of likely Indo-European R1b lineages among the Basques is curious, and may point to the spreading of male patronization networks, and their assimilation into non-Indo-European substrates where necessary. R1b is also found in Sardinia, and in high frequencies in much of Italy.

The interaction and synthesis between native and newcomer was likely intensive in the Mediterranean. For example, of the gods of the Greek pantheon only Zeus is indubitably of Indo-European origin. Some, such as Artemis, have clear Near Eastern antecedents. But other Greek gods may come down from the pre-Greek inhabitants of what became Greece.

Ultimately these copious interactions and transformations should not be a great surprise. The sunny lands of the Mediterranean attracted Northern European tribes during Classical antiquity. The Cimbri invasion of Italy, Galatians in Thrace and Anatolia, the folk wandering of Vandals and Goths into Iberia, are all instances of population movements southward. These likely moved the needle ever so slightly toward convergence between Northern and Southern Europe in terms of genetic content.

In relation to the more general spread of Indo-Europeans, I believe there are a few areas like Northern Europe, where replacement was preponderant (e.g., the Tarim basin). But I also believe there were many more which presented a Southern European model of synthesis and accommodation.

The Bronze age demographic transformation of Britain

In Norman Davies’ the excellent The Isles: A History, he mentions offhand that unlike the Irish the British to a great extent have forgotten their own mythology. This is one reason that J. R. R. Tolkien created Middle Earth, they gave the Anglo-Saxons the same sort of mythos that the Irish and Norse had.

But to some extent I think we can update our assessments. Science is bringing myth to life. The legendary “Bell Beaker paper” is now available in preprint form, The Beaker Phenomenon And The Genomic Transformation Of Northwest Europe. The methods are not too abstruse if you have read earlier works on this vein (i.e., no Nick Patterson authored methodological supplement that I saw). And the results are straightforward.

And what are those results?

First, the Bell Beaker phenomenon was both cultural and demographic. Cultural in that it began in the Iberian peninsula, and was transmitted to Central Europe, without much gene flow from what they can see. Demographic in that its push west into what is today the Low Countries and France and the British Isles was accompanied by massive gene flow.

In their British samples they conclude that 90% of the ancestry of early Bronze Age populations derive from migrants from Central Europe with some steppe-like ancestry. In over words, in a few hundred years there was a 90% turnover of ancestry. The preponderance of the male European R1b lineage also dates to this period. It went from ~0% to ~75-90% in Britain over a few hundred years.

If most of the genetic-demographic character of modern Britain was established during the Bronze Age*, then there has been significant selection since the Bronze Age. The figure to the left shows ancient (Neolithic/Bronze age) frequencies of selected SNPs, with modern frequencies in the British in dashed read. The top-left SNP is for HERC2-OCA2, the region related to brown vs. blue eye color, and also associated with some more general depigmentation. The top-right SNP is in SLC45A2, the second largest effect skin color locus in Europeans. The bottom SNP is for a mutation on LCT, which allows for the digestion of milk sugar as adults.

The vast majority of the allele frequency change in Britons for digestion of milk sugar post-dates the demographic turnover. In other words, the modern allele frequency is a function of post-Bronze Age selection. This is not surprising, as it supports the result in Eight thousand years of natural selection.

1000 Genomes derived SLC45A2 SNP frequency

At least as interesting are the pigmentation loci. The fact that the derived frequency in HERC2-OCA2 is lower in both British and Central European Beaker people samples indicates that the lower proportion is not an artifact of sampling. Britons have gotten more blue-eyed over the last 4,000 years. Second, SLC45A2 is at shocking low proportions for modern European populations.

HGDP derived SLC45A2 SNP frequency

In the 1000 Genomes the 4% ancestral allele frequency is almost certainly a function of the Siberian (non-European) ancestry. In modern Iberians the ancestral frequency is 18% (and it is even higher in Sardinians last I checked), but in Tuscans it is ~2%. Though not diagnostic of Europeans in the way the derived SNP at SLC24A2 is, SLC452 derived variants are much more constrained to Europe. Individuals who are homozygote ancestral for SNPs atSLC45A2 rare in modern Northern Europeans (pretty much nonexistent actually). But even as late as the Bronze Age they would have been present at low but appreciable frequencies.

This particular result convinces me that the method in Field et al. which detected lots of recent (last 2,000 years) selection on pigmentation in British populations is not just a statistical artifact. Though these papers are solving much of European prehistory, they are also going to be essential windows into the trajectory of natural selection in human populations over the last 5,000 years.

* In the context of this paper the Anglo-Saxon migrations tackled by the PoBI paper are minor affairs because the two populations were already genetically rather close. Additionally, the PoBI paper found that the German migrations were significant demographic events, but most of the ancestry across Britain does date to the previous period.

The lesson of Erasmus: the center that could not hold

The return of the civilian

“On the coming of evening, I return to my house and enter my study; and at the door I take off the day’s clothing, covered with mud and dust, and put on garments regal and courtly; and reclothed appropriately, I enter the ancient courts of ancient men, where, received by them with affection, I feed on that food which only is mine and which I was born for, where I am not ashamed to speak with them and to ask them the reason for their actions; and they in their kindness answer me; and for four hours of time I do not feel boredom, I forget every trouble, I do not dread poverty, I am not frightened by death; entirely I give myself over to them”
-Niccolò Machiavelli

The sentiments expressed above are typical of Renaissance men, prone to archaisms and love of ancient learning. As all stylized facts are, the dichotomy between a dark Middle Ages and a flourishing Renaissance are clearly overwrought, and an artifact in some ways of the reality that the victors write history. A passionate intellectual such as Abelard is clearly a familiar figure despite the reality that he flourished in the early part of the High Middle Ages. And the period described in Aristotle’s Children was not lacking in brilliance on the whole.

But generalizations also have a basis. Henry the VIII reputedly wrote Defence of the Seven Sacraments as a rebuke to the assaults from the nascent Protestant tradition. For his services the Pope gave the king the title Defender of the Faith. It is no surprise that Thomas More “aided” in the composition, but the point is that a Renaissance monarch was expected to be a cultured individual for whom writing a theological treatise was not ludicrous.

Though one should not take the analogy too far, in some ways the polities of the medieval period in Western Europe exhibited a social structure not unlike that of the Bronze Age. Literacy was one of the hallmarks of Romanitas, and later of Christian civilization. But literacy was not broad-based in Western Europe, but rather concentrated in a particular caste, that of the priests. In the Bronze Age literacy was also defined by its caste association, that of the scribes. In contrast, kings fought. Their rule was by divine right, whether as living gods on earth, or as vice-reagents of the national deity. Similarly, monarchs during the medieval period ruled as representatives of the God on high.

During the Iron Age the antipodes of Eurasia were dominated by polities and civilizations which were predicated on military rule, but at whose peak civilian norms reigned supreme. Even as militaristic a figure as Julius Caesar was a cultural patron who also wrote The Gallic Wars. Similarly the Chinese emperors were manifestly civilian figures, who often also had personal skills in the arts which they cultivated. It wasn’t until the reign of the emperor Justin in the year 518 that Rome first had an illiterate ruler (and this is implausible enough that some historians attribute this claim as one intended to be scurrilous toward Justin and his successor and nephew, Justinian).

The fall of the Western Roman Empire ended this civilian ascendancy, which in any case was being eroded by the necessary rise of military emperors to defend the borders against barbarian incursions. Once the German tribes, Roman allies or not, took the reins of power there were deep fundamental transformations of the order of society. Though great rulers such as Charlemagne were patrons of learning and Roman civilization, he himself remained very much a barbarian warlord.

The ruling elite of medieval Europe were manifestly a military elite. The feudal system demanded that they provide service in the armies of their lords, and that service entailed outfitting themselves and a retinue. Martial skills were a necessity. The legacy of this physical aspect to being part of the ruling elite persists down to the present day. Both of the two young princes in the House of Windsor have had military careers, while hunting remained a major part of every nobleman’s life down to the early modern period (apparently Louis XVI’s diaries are filled with days which simply state “went hunting”).

The gun and the printing press

Events such as the Battle of Crecy, the rise of the Swiss infantry, and the ubiquity of the gun, heralded the end of the military elite as a necessity. Gentility of birth became a matter of mores and manners, and the reemergence of an almost classical model of education and cultivation took hold.

Along with the the rise of the gun, there was the printing press. The existence of ancient graffiti in Egypt and Rome tells us that we should be cautious about assuming that literacy was rare in antiquity, but we should also admit that it was not quite common (when men of the lower classes were allowed in the legions in the late republic there were accommodations made for the fact that many would be illiterate).

The printing press was a technology that made production of printed works much easier. And so Europe was indudated with pamphlets and books. This was not always due to the literate content, as illustrations were quite influential. But it is hard to deny that this spread of information technology probably triggered a blooming of the “republic of letters” not out of chance, but necessity. The intellectuals of the medieval period were by and large clerics, but now they were joined by newly emerged urban professionals and the leisured nobility.

The Age of the Princes and their Liberal Critic

As medieval Western Christendom entered into the final stages of putrefaction something new was ripening within it. I do not believe it is coincidental that the Iberian powers were pushing forward and exploring the world beyond Europe in the decades before Martin Luther, and during the same period new learning was overturning the long reigning scholasticism.

At the center of much of the cultural religious ferment was Desiderius Erasmus. Born in 1466, he was the illegitimate son of a priest, and became a priest himself. After a fashion he was man of the later medieval period, born of a cleric who violated his vows of chastity, in the decades after the papacy was riven between different claimants, and conciliarism attempted to throw the Western Church back to a more antiquated style of governance. This was the age of the Borgia and Medici popes.

Erasmus’ accomplishments are legion in the field of humanities. Today he would be a stellar public intellectual, as well as a productive research scholar. He was the prince of the republic of letters of his day.

Like many Catholic reformers Erasmus aimed to sweep the superstition from his faith, and mocked and criticized the corruptions that he saw in the Church. With his pen he attempted to reform Christian civilization in his own image, sincere of faith and theologically orthodox, shorn of the idolatrous excesses of the medieval Catholicism, with its cult of saints and Marian devotions, as well as contemptuous of the hypocrisy of the clerical class as a whole (though still reverential of its role in performing the sacraments).

Erasmus was instrumental in the rebirth of the liberal arts in Europe in his day. But it seems clear that Erasmus was also fundamentally a liberal person in his attitude toward deviation from what he himself thought was true and right. And, events at the end of his life also suggest that he was much more accepting of the imperfections of the institutions which he critiqued throughout his whole life than others would be.

The Age of the Zealot

The last 19 years of Erasmus’ life overlapped with the Reformation. At the peak of his fame and influence men such as Luther reached out to him, but Erasmus did not return their enthusiasm in kind. The Reformation unleashed atavistic passions, and much of the world Erasmus had known, that he had critiqued and chided, collapsed before him.

Where Erasmus inveighed against the corruption of the Catholic Church, zealous new converts to the Protestant cause destroyed church property and relics, and expelled priests from their territory. When the Jews did not convert to Luther’s form of Christianity, he attacked them. When the peasants rose up against their lords, analogizing their rebellion to that of Luther and his colleagues, he justified their slaughter. When Erasmus temporized Luther attacked him.

Though there were long periods of peace in the decades after Erasmus’ death, the St. Bartholomew’s Day massacre became emblematic of an age. The period of the Reformation is also one of the age of Wars of Religion. The whole map of Europe transformed due to religious disputes, and between 25 to 50 percent of the population of the German nation died during the Thirty Years War due to causes rooted in the war itself.

In Northern Europe they burned witches. In Southern Europe the inquisition was in full effect. In France Protestants and Catholics lived separate lives, until the French monarchy gave the Protestants a choice of conversion or emigration.

Ideas With Consequences

In Erasmus’ life and work we see the shadow of the future. Some figures just subsequent to him, such as Montaigne, echoed his liberality of spirit. But they were marginalized for centuries by the intolerance of Luther, the controlling character of Calvin, and the machinations of the Jesuits. The power of monarchs grew, as they dispossessed the Catholic Church, or claimed that the Catholic Church gave them divine right to rule.

Charity toward those with whom one disagreed with, a plea of Erasmus in his later  years, disappeared. And what reason had the Catholics to be generous to the Protestants after the iconoclastic attacks on their sacred sites and objects? Protestants when they were expelled or forcibly converted by Catholics? Reformed when they were driven out of Lutheran and Catholic lands? Baptists when they were oppressed everywhere?

The decline of the centrality of fighting as the primary task of nobles, and the rise of humanist and cultured values among the aristocracy, was coincident with wars which tore the fabric of Europe apart for generations, over and over.

The Exhausted Return

Of course as I write today in 2017 the figure of Erasmus strikes many moderns, whatever our religious inclinations, as an admirable one. His emphasis on heart, and the fact that his heart was in the right place, are appealing. His liberality of spirit, his low tolerance for hypocrisy and corruption, but acceptance of genuine disagreement due to human fallibility, are characteristics many of us would wish we could cultivate more.

But it’s nearly 500 years since he died, and it took about two centuries after he died for the long road to enlightenment to put us where we are now. Erasmus shows us that a moderate position, taking the middle path, speaking in the language of intellectuals, has difficulties with the zealots who spew the argot of the street. John Calvin had a humanist education, as did many of the Reformers were humanists, but that did not prevent him from burning a heretic and giving voice to his inner totalitarian (though I do understand that Geneva was not totalitarian in a way we would understand it today). Humanism became a tool, part of one’s education, as opposed to the broad liberal minded spirit with Erasmus exemplified.

When learning is instrumentalized, when it is reduced purely to a tool in the service of society, that enslavement saps something out of its spirit. The idea of truth, the valorization of it above other things, likely does have broader cultural consequences. Without truth, I believe that our species reverts to zero-sum and negative-sum “games.” That was our past. I believe it could be our future.


The great Han Empire in Africa

Howard French’s China’s Second Continent: How a Million Migrants Are Building a New Empire in Africa is a bit cliche. Rather than a scholarly book it’s more an observational travelogue, and it suffers somewhat from the fact that it is focused on Chinese who live in Africa, but are never of it. Chinese are Chinese, and those who migrate to Africa have more commonalities than most. So French’s attempts to spin out distinct experiences was a bit stretched. Basically, the same thing is happening over and over across the African continent.

When I say this that it is cliche, I’m alluding to the fact that for many Chinese presence in Africa is rather well known. But the reality is not everyone knows about it. So I was happy to see The New York Times put this issue front and center, Is China the World’s New Colonial Power?

There are twists which are important to remember. First, China’s working age population has been declining since 2012. This is going to put a crimp in any “imperial” ambitions. Second, this Chinese “empire” is not going to be an explicitly political one, but rather one of influence, control, and tough soft power.

That being said, we should’t underestimate the will and need of the Chinese to have their “time in the sun.” Fifteen years ago Ross Terrill wrote The New Chinese Empire. In it be observed that for much of Chinese history there has long been a division between a moralistic/ideological camp and a more nationalist realpolitik element. He traces this division back to antiquity, with Confucianism and Legalism as the prototypes (I’m not sure I believe this). But Terrill observed that Deng Xiaoping and the leaders who he cultivated and promoted to succeed him were generally much more nakedly nationalistic than Mao ever was.

Just something to keep in mind as we look to the future….

The coming of the Milesians: abstract of “The Bell Beaker Paper” (tBBp)

I get asked about this all the time, and promised I’d post something first I heard anything, so here is a foretaste, Western Europe during the third millennium BCE: A genetic characterization of the Bell Beaker

The Bell Beaker Complex (BBC) was the first widely distributed archaeological phenomenon of western Europe, arising after 2800 BCE probably in Iberia and spreading to the north and east before disappearing at the latest by 1800 BCE. An open question is the extent to which the cultural elements associated with the BBC spread through movement of ideas or people. We present new genome-wide DNA data from 196 Neolithic and Bronze Age Europeans – the largest report of genome-wide data in a single study to date – and merge it with published data to form a dataset with 109 BBC individuals that provides a genomic characterization of the BBC across its geographic and temporal range. In contrast to people of the Corded Ware Complex who were partly contemporaries of the BBC in central and eastern Europe and who brought steppe ancestry into central Europe through mass migration and replacement of local populations, we show that the initial spread of the BBC into central Europe from the Iberian Peninsula was not mediated by a large-scale migration but rather through communication of ideas. However, the further spread of the BBC beyond central Europe did involve mass movement of people. Focusing on Britain, which includes 81 of our new samples in a time transect from 3900-1300 BCE, we show that the arrival of the BBC around 2400 BCE was mediated by migration from the continent: British individuals associated with Beakers are genetically indistinguishable from continental individuals associated with the same material culture and genetically nearly completely discontinuous with the previously resident population. Such discontinuity persists through to samples from the Bronze Age, documenting a demographic turnover at the onset of the Bronze Age that was crucial to understand the formation of the present-day British gene pool. The arrival of the BBC in Britain can thus be viewed as the western continuation of the massive movement of people that brought the Corded Ware Complex and steppe ancestry into central Europe a few hundred years before.

Ancient DNA has revolutionized our understanding of the history of the past. In a fundamental manner many archaeologists were wrong in assuming that the dominant dynamic of the spread of culture was that of the diffusion of ideas, as opposed to the movement of peoples. But to interpret these results it is clear that archaeological knowledge must be brought to bear, albeit updated with knew prior assumptions.

It would not be entirely surprising if the originators of a cultural complex transmitted it to another group, and then that culture “hitchhiked” on the demographic expansion of the receiving group. A good example would be Roman Catholic Christianity. The Iberians spread it to the New World, along with substantial demographic movement. But the religion itself did not spread to Iberia through migration, but rather cultural shift.