A few weeks ago, Peter Turchin, who runs the excellent Social Evolution Forum, published a paper in PNAS, War, space, and the evolution of Old World complex societies. It is open access, so you can read it yourself. And Turchin himself has responded to questions at length. You might also check out my reviews of two of his books, as well as my interview with him. From all that it should be clear that broadly speaking I am enthusiastic about Turchin’s project, Cliodynamics. Historical details matter, but Turchin’s aim is to establish a broad brush framework of the coarse dynamics which shape the scaffold for specific aspects of historical process. Without this background all we have are cluttered details.
Dienekes has a post up highlighting a preprint out of Pontus Skoglund’s group. It is titled Ancient genomes mirror mode of subsistence rather than geography in prehistoric Europe. It doesn’t seem to be online (fingers crossed that it shows up linked at Haldane’s Sieve soon). In any case I am not surprised by the broad outlines of the thesis. And, it is not as if Skoglund’s group is the only one working in this area, I have suspicions that others are finding something very similar. These results out of Europe are probably reflective of the fact that much of the model in Peter Bellwood’s First Farmers is generally correct, the emergence of an agriculture revolution in a few select world societies produced a cultural and demographic revolution.
Today Dienekes points to a PLoS ONE paper, mtDNA from the Early Bronze Age to the Roman Period Suggests a Genetic Link between the Indian Subcontinent and Mesopotamian Cradle of Civilization. The title is pretty self-explanatory, though above I’ve posted a figure which shows the mtDNA haplogroup affiliations of the four individuals dated to between 2500 BC and 500 AD. If you are a even moderately familiar with the human mtDNA phylogeographic literature then you know that haplogroup M is not West Eurasian, and these lineages are often South Asian. The existence of people of South Asian origin in West Asia during the Roman period is rather unsurprising, the Persian (and Hellenistic) polities spanned West and South Asia (albeit, in a liminal sense in the latter case). But what about extremely ancient finds? This too has an explanation. From Brotherhood of Kings: How International Relations Shaped the Ancient Near East:
Several years ago I reviewed Christopher Beckwith’s magisterial Empires of the Silk Road: A History of Central Eurasia from the Bronze Age to the Present. In many ways Beckwith’s narrative is a refreshing inversion of the traditional form of macrohistory, whereby charter societies along the Eurasian littoral issue civilizing tendrils toward the heartland, and are met with periodic barbaric eruptions which they then have to assimilate. From what I can gather Beckwith is not a subjectivist. Rather, the inversion of perspective serves to flesh out neglected dynamics at work across history and near prehistory. For example he highlights the reality that core polities of the Eurasian littoral often crystallized on the barbaric marches of established civilization via process of synthesis between the two cultures. Zoroastrian religion emerged on the northern frontier in Khorasan rather than the southwestern Iranian heartland of Fars. Han China’s predecessor in the form of the Chin dynasty arose from a marcher state in the northwest, and the same was true of the previous ruling house, that of the Zhou. In India classical Hindu civilization first congealed in an elaborated form in Magadha, on the eastern frontiers of Aryavarta. In the West Rome was fundamentally a barbaric and peculiar fringe polity, with only tenuous connections to Magna Graecia, and arguably more influenced by the enigmatic Etruscans.
The vigor of frontiers is such an established historical cliche that I have no great enthusiasm to revisit it in detail. Rather, following Beckwith I believe we need to seriously revisit the proposition that the vast expanses of the Eurasian heartland beyond the civilized frontiers have served as more than just a source of militarized barbarians bent on exploitation. Yes, all that is true, but it seems likely that the cultural and racial melange at the intersection of internal Eurasian trade networks have fundamentally reshaped the contemporary landscapes in ways we are only now beginning to understand. But first, our worldview has to acknowledge that not all peoples and lands have made contributions of equal weight to the shape of the world.
The genetics and history of Tibet are fascinating to many. To be honest the primary reason here is elevation. The Tibetan plateau has served as a fortress for populations who have adapted biologically and culturally to the extreme conditions. Naturally this means that there has been a fair amount of population genetics on Tibetans, as hypoxia is a side effect of high altitude living which dramatically impacts fitness. I have discussed papers on this topic before. And I will probably talk more about it in the future, considering rumblings at ASHG 2012.
But to understand the character of the effect of natural selection on a population it is often very important to keep in mind the phylogenetic context. By this, I mean that evolutionary processes occur over history, and those historical events shape the course of subsequent of phenomena. Concretely, to understand how the Tibetans came to be adapted to high altitudes one must understand who they are related to, and what their long term history is. There is a paper in Molecular Biology and Evolution which attempts to do just that, Genetic evidence of Paleolithic colonization and Neolithic expansion of modern humans on the Tibetan Plateau:
A few years ago I predicted to some friends that ancient DNA would transform our understanding of the human past. The reason being that inferences of population movements via material remains were imprecise at best. We are beginning to see my prediction come to fruit (mind you, the prediction was not a bold or courageous one). A new short communication in Nature Communications, A European population in Minoan Bronze Age Crete, addresses an old and frankly somewhat outdated question: whether the first European literate civilization derived from a transplantation from Egypt, or was autochthonous.
I say that this is a somewhat outdated test because the modern proponent of this theory, Arthur Evans, lived a century ago, when our understanding of pre-Classical antiquity (i.e., the world before 600 BC and literate alphabetic Greek civilization) was sketchy at best. The reality is that ancient Crete, like the ancient Levant, does seem to have been in the greater Egyptian culture sphere of influence, just as ancient Elam (southwest Iran) was a de facto part of the Mesopotamian world. But we know the language of the Elamites, and it was not related to Mesopotamian languages. Just as the Finns have been influenced by their Nordic neighbors, so were the Elamites influenced by their Sumerian neighbors. But their linguistic difference points to fundamentally distinct origins. And so it is with the Minoans. It was already likely from the peculiar nature of Minoan writing, Linear A, that this civilization was not a simple derivation of Egypt. These genetic data just add more evidence.
Standard apologies that I have had not the marginal time to blog much, but I thought it was important that I least note that Dr. Peter Ralph and Dr. Graham Coop’s paper on identity-by-descent segments and European populations and history is out in its final form in PLoS Biology, The Geography of Recent Genetic Ancestry across Europe. I’ve been familiar with the outlines of these results for about a year now, and to be frank I am still digesting them. The media hype will come and go, with true but to some extent trivial headlines that “all Europeans are related,” but the consequences of these sorts of genetic inquiries into the relatedness of populations are going to be long lasting. At least they should be.
But before I go on about that, if you find the paper itself a bit daunting (though the main body of the text strikes me as eminently readable for a piece of statistical genetics), see Carl Zimmer’s condensation. With this sort of result there is liable to be confusion, so note that Graham Coop has been posting comments on Carl’s blog (and elsewhere, and you can always send him a note on Twitter). Additionally he has a very readable FAQ out. Dr. Coop told me on Twitter that there would even be updates tomorrow as well! In particular one aspect of the paper which I noticed is that most relatively short, but detectable segments (~10 cM), between any two individuals in many nationalities is not going to be evidence of recent genealogical affinities, but deeper historical process.
For whatever reason The New York Times has been putting out many articles on Myanmar recently. For example, Buddhist-Muslim Tensions Spread as 8 Detainees Die in Indonesia. Second, Ethnic Rifts Strain Myanmar as It Moves Toward Democracy. I’m a subscriber to The New York Times, so I think the paper of record is worthwhile. But quite often its international pieces lack historical and cultural context, and don’t impart the heart of the matter to readers. (see: The New York Times flubs basic facts about Islam) First, the simple part. The “religious conflict” in Myanmar is really just an ethnic-racial conflict. Demographic statistics from Myanmar are pretty woolly, so one can’t say anything with any great confidence, but it seems likely that the majority of Muslims in that nation are ethnic Rohingya. These Rohingya derive from agriculturalists who emigrated at some point in the last few centuries from eastern Bengal, and, that is the region which has always been predominantly Muslim. There are two giveaways as to their origin. First, their language (from Wikipedia):
When I read Genome-Wide Diversity in the Levant Reveals Recent Structuring by Culture in PLoS Genetics last week, one of my thoughts was “where is the tree”? Thankfully all the data is online, so I simply ran TreeMix on it. After a number of runs I know understand perhaps why there is no figure emphasizing a tree. There just isn’t that much informative yield from what I can tell, though the basic inference from the paper is recapitulated. You can see the results in the figure above, from one of my TreeMix runs. Overall, what this paper reinforces is that there are sharp genetic distinctions across ethno-religious boundaries within the modern Middle East which confound attempts to use geography to predict variation.
With great ambition comes the opportunity for stupendous failure. If one does not strive, one can not fail in a bold manner. And Ian Morris is bold indeed. I read his previous book, Why the West Rules–for Now: The Patterns of History, and What They Reveal About the Future, and found in enjoyable. And yet it isn’t that original a departure from many economic histories one might encounter. This is a major worry I have with Morris’ new book, The Measure of Civilization: How Social Development Decides the Fate of Nations. Is there anything here that Angus Maddison fans will find novel?
One of my resolutions for the New Year was to read two books on approximately the same period and place in sequence, The Fall of Rome: And the End of Civilization, and Through the Eye of a Needle: Wealth, the Fall of Rome, and the Making of Christianity in the West, 350-550 AD. Despite a very general similarity of topicality it would be misleading to characterize these two books as complementary, or with one as a sequel to the other. Rather, they use explicitly different methods and espouse implicitly alternative norms in generating a map of the past. As I have explored in depth Bryan Ward-Perkins’ The Fall of Rome is to a great extent a materialist reading which reasserts the contention that civilization as we understand it did truly collapse in a precipitous and discontinuous manner with the fall of Rome. In other words, in all things that matter the year 400 was much closer to the year 300 than it was to the year 500. But it is critical to qualify what “matters.” As an archaeologist with a penchant for economic history Ward-Perkins’ materialist narrative might be reduced down to a metric, such as productivity per person as a function of time. In such a frame the preponderance of evidence does suggest that there was collapse in the Western Roman Empire in the years between 400 and 500. But specific frame is not something that we can take for granted. Peter Brown, the author of Through the Eye of a Needle might object that there is more to man than matter alone. A major distinction between the years 400 and 500, as opposed to 300, is that in the first quarter of the 4th century the Roman Emperors starting with Constantine began to show special favor to the Christian religion, which by 400 was on the way to being the exclusive official faith of the Empire, a process which was complete by 500. The Rome of 300 was indisputably a pagan one. That of 400 arguably Christian, and 500 most definitely Christian.
Unfortunately history is a discipline where we can not run experiments. From my earlier posts it should be clear that I have a keen interest in Western antiquity. But another passion of mine is Chinese history. A frustrating experience I have is that many people feel confident in making cross-cultural generalizations despite having deep familiarity with only one civilizational tradition. A comparative perspective is highly illuminating, but only if you stand on a solid ground of factual bases from which to actually make comparisons. The existence of complex societies at both ends of Eurasia over the past 2,500 years are fascinating parallel “natural experiments.” But to compare and contrast you need to know a great deal about both civilizations.
Increased knowledge enriches discussion, and in the near future this weblog will once again have vibrant comments sections. With that in mind here are some books on Chinese civilization which I have found informative and useful:
Bryan Ward-Perkins in The Fall of Rome: And the End of Civilization spends a great deal of time on the archaeology of the Classical and post-Classical world. But, he also devotes only somewhat less space to the historiography of the study of the Roman Empire, and Late Antiquity. That is because the study of the past is not just the study of the past, but it is the study of the concerns and values of the present. We look through the dark mirror to the past, and in it we see our own outlines. Similarly, science fiction which purports to be a projection of the future is often nothing much more than a retelling of the present in shinier garb. This reality of history, its reflection of the prescription of the present despite the conceit that it is a description of the past, needs to be kept in mind. It is not a failing which pollutes the whole enterprise, it is a reality which must inform our interpretation of it. The study of Rome is a study of what humanity was, but it can not help but also reflect and define what we wish to be, by comparison and contrast.
But before I go on, a minor mea culpa. After further research and correspondence I believe that I extrapolated too far from lead concentrations in Greenland ice caps in a previous post. Though I still believe that it is a good reflection of the decline in proto-industrial vigor in the Western world, I do think that distance from China means that we do not have a good gauge on any comparisons between 0 AD and 750 AD (the later date being the apogee of the Tang). Though I do note that world population estimates seem to be somewhat lower for 700 than 0. But these are not precise estimates, so they need to be taken with a grain of salt. Chinese census records indicate that Tang population was higher than that of the Han, while it seems plausible that the Arab Imperium of the 8th century resulted in a higher population for the regions under its purview than during antiquity. Therefore to make the “math work” one can reasonably assume that the population in Europe was far lower.
Before the Holidays I mentioned that I was rereading Bryan Ward-Perkins’ The Fall of Rome: And the End of Civilization. Why do I hold this book in such high esteem? Because of figures such as the one to the left. Granted, this chart is not from The Fall of Rome, but that book has an extensive bibliography which drew me to research on long term trends in pollutant concentrations. What you see illustrated are variations in the concentration of lead in ice cores from Greenland. Why is lead so important? Because it is a noxious byproduct in various primitive metallurgical processes. The basic thesis that Ward-Perkins fleshes out in great detail in The Fall of Rome is that the material basis of European life suffered a sharp regression after the collapse of the Roman Empire. In short the fall of Rome was the end of civilization, and what came after was coarser and more elementary in character. This may seem “common sense,” but it is actually a matter of some dispute and debate in the academy.
One of the great aspects of owning a Kindle has been that I have been able to load it with cheap copies of “classics.”* As it happens I had physical copies of many of these works, but often it became difficult to keep track of various books in even my modest personal library. Generally scientific references were placed prominently, and I made use of them often, and so always was able to mark exactly where they were. But when it came to Nicomachean Ethics or The Critique of Pure Reason, I would proactively seek them on only rare occasions. Now with a compact and well organized personal digital library I find that I revisit the ancients much more often to engage with them in dialogue. Here I recall what Niccolò Machiavelli once asserted:
When evening comes, I return home and go into my study. On the threshold I strip off my muddy, sweaty, workday clothes, and put on the robes of court and palace, and in this graver dress I enter the antique courts of the ancients and am welcomed by them, and there I taste the food that alone is mine, and for which I was born. And there I make bold to speak to them and ask the motives of their actions, and they, in their humanity, reply to me. And for the space of four hours I forget the world, remember no vexation, fear poverty no more, tremble no more at death: I pass indeed into their world.
A few months ago someone asked me (via email) which populations I would love to get typed (genetically that is). There is one population which did not come to mind at the time: the Sumerians. Why? Because these are arguably the first historic nation. The first self-conscious ethnic group which operated by the rules which we define as the fundamentals of literate civilization. Strangely, they are an ethno-linguistic isolate. My own assumption until lately has been that this is not too surprising, in that prior to the rise of expansive civilizations (Sargon of Akkad) there was much more linguistic and ethnic diversity than we currently see around us. Or, was evident even in the early Iron Age. In other words, the ancient Fertile Crescent may have resembled the highlands of Papua, with Hurrians, Akkadians, Gutians, Elamites, Sumerians, etc., all speaking mutually unintelligible dialects which diverged very far back in the mists of antiquity.
I am no longer quite so sure about this model. That is largely due to the possibility that there was a great deal of demographic change between the Mesolithic and the Bronze Age, with successive waves of layering and replacement. My rough model is that a few groups of farmers may have expanded to swallow up thousands of hunter-gatherer groups. These homogeneous farmer societies eventually would diversify, because they were not united by the institutional forces which cemented later imperial regimes, in particular, literate elites which had a sense of consciousness which extended deep into the past because of written records. Therefore, the diversification would presumably have been similar to what we see with Romance languages, or Indo-Aryan, branching out from an common root language which replaced many competitors rapidly. Without writing and large scale polities the divergence would be more rapid, and there would be many more tips on the phylogenetic tree.
Analogies exist to convey information. But too often all they do is add rhetorical flourish. For an analogy to have power there needs to be a genuine mapping of the structure of the source and target. And perhaps more crucially your target audience needs to understand the structure of the source well enough to map it onto the target. You can’t get insight from a foundation of nothing.
A story in The New York Times suggested to me one avenue by which to communicate the particular nature of the relations in Syria between ethno-linguistic groups. Syrian Children Offer Glimpse of a Future of Reprisals:
The roots of the animosity toward the Alawites from members of Syria’s Sunni Muslim majority, who make up about 75 percent of the population, run deep into history. During the 19th-century Ottoman Empire, the two groups lived in separate communities, and the Sunni majority so thoroughly marginalized Alawites that they were not even allowed to testify in court until after World War I.
If you haven’t, you should check out The Shadow Scholar, The man who writes your students’ papers tells his story. This is the conclusion:
“Thanx u so much for the chapter is going very good the porfesser likes it but wants the folloing suggestions please what do you thing?:
“‘The hypothesis is interesting but I’d like to see it a bit more focused. Choose a specific connection and try to prove it.’
“What shoudwe say?”
This happens a lot. I get paid per assignment. But with longer papers, the student starts to think of me as a personal educational counselor. She paid me to write a one-page response to her professor, and then she paid me to revise her paper. I completed each of these assignments, sustaining the voice that the student had established and maintaining the front of competence from some invisible location far beneath the ivory tower.
The 75-page paper on business ethics ultimately expanded into a 160-page graduate thesis, every word of which was written by me. I can’t remember the name of my client, but it’s her name on my work. We collaborated for months. As with so many other topics I tackle, the connection between unethical business practices and trade liberalization became a subtext to my everyday life.
So, of course, you can imagine my excitement when I received the good news:
“thanx so much for uhelp ican going to graduate to now”.
The author claims that his three primary customer demographics are “English-as-second-language student; the hopelessly deficient student; and the lazy rich kid.” In the above case it looks like the first category. But what are the proportions? I assume that the lazy rich kids are mostly undergraduates or MBA students.
|Spatial linguistic variation||Spatial genetic variation||Temporal linguistic variation||Temporal genetic variation|
|Modern Age||Very low||Low||Low||Moderate-to-low|
In the comments below I posited a scenario to explain a strange inference from a paper from a few years back, Sequencing of 50 Human Exomes Reveals Adaptation to High Altitude:
Population historical models were estimated (8) from the two-dimensional frequency spectrum of synonymous sites in the two populations. The best-fitting model suggested that the Tibetan and Han populations diverged 2750 years ago, with the Han population growing from a small initial size and the Tibetan population contracting from a large initial size (fig. S2). Migration was inferred from the Tibetan to the Han sample, with recent admixture in the opposite direction.
2,750 years would place the divergence of modern Tibetans and Chinese a few hundred years before Confucius. In fact, it would technically post-date the first historically attested Chinese writing, from the Shang dynasty. This result was pretty incredible, though one of the main authors believes it is a reasonable estimate. There are many ways you can explain this sort of divergence time, but one way which I elucidated below is rather simple. Imagine, if you will, a large set of populations which are culturally very distinct, but engage in gene flow with each other. This is not a preposterous scenario. Because of the restrictions on the manner in which genes are inherited, and the flexibility of cultural traits in terms of transmission, you often have situations where change in allele frequency is clinal while change in culturae is punctuated. To give a concrete example, moving along a transect on the North European plain will result in a gradual change in allele frequencies, but a crisper shift in languages spoke. The two are not totally distinct. Allele frequencies will tend to shift more at language boundaries, but whereas most of the difference is between groups across languages, in relation to genes usually the differences are within groups.
Estimating a date of mixture of ancestral South Asian populations
Linguistic and genetic studies have demonstrated that almost all groups in South Asia today descend from a mixture of two highly divergent populations: Ancestral North Indians (ANI) related to Central Asians, Middle Easterners and Europeans, and Ancestral South Indians (ASI) not related to any populations outside the Indian subcontinent. ANI and ASI have been estimated to have diverged from a common ancestor as much as 60,000 years ago, but the date of the ANI-ASI mixture is unknown. Here we analyze data from about 60 South Asian groups to estimate that major ANI-ASI mixture occurred 1,200-4,000 years ago. Some mixture may also be older—beyond the time we can query using admixture linkage disequilibrium—since it is universal throughout the subcontinent: present in every group speaking Indo-European or Dravidian languages, in all caste levels, and in primitive tribes. After the ANI-ASI mixture that occurred within the last four thousand years, a cultural shift led to widespread endogamy, decreasing the rate of additional mixture.