Völkerwanderung back with a vengeance | Gene Expression


The German magazine _Der Spiegel_ has a rather thick new article out [reviewing][2] the latest research which is starting to reintroduce the concept of [mass folk wanderings into archaeology][3]. The title is [How Middle Eastern Milk Drinkers Conquered Europe][4]. In the story you get a good sense of the recent revision of the null model once dominant within archeology that the motive forces of history manifested through the flow of [pots and not people][5]. This viewpoint came to ascendancy after World War II, and succeeded an older method of interpretation which presumed a tight correlation between race and culture. It repudiated the idea that the flow and change of pottery styles and extant patterns of linguistic dialects may have been markers for the waxing and waning of peoples.

Obviously a pots-not-people model had some major exceptions even during its heyday. The demographic explosion of European peoples after 1492, and especially the [Anglo peoples after 1700][6], occurred within the light of history. Even if it hadn’t it would be ludicrous on the face of it to assert that the modern American population were derived from the indigenous populations, and that they had simply adopted the language, religion and folkways of the British conquerors of North America. But outside the presumed aberration of the European imperialist and colonial venture of the modern era the details on the ground were obscure enough that a model could be imposed from without.

No longer. In non-European societies such as China with extensive records it is [clear][7] that demographic increase and colonization were driving forces of the expansion of a given cultural domain. A neglect of this reality could only occur via ignorance of the primary documents. Plausible if one did not know Chinese. As in the case of [Spanish conquest of the New World][8] the demographic wave was not total; [biological][9] and cultural amalgamation with the native substrate south of the Yangtze did occur to produce a new synthesis. But the revision does not occur just through space, but time as well. The methods of genetics, whereby samples from ancient burials may be retrieved and compared to modern populations, have [allowed us to reject][10] the post-World War II assumption that the Etruscans were an indigenous Italian culture. Due to the lack of copious records a theoretical presupposition was able to interject itself into the data. When the story about Etruscan genetic relationships to Near Eastern groups broke in early 2007 I actually proceeded to skim the latest archaeological monographs on the archaeology of this group, and most of them had erudite expositions on exactly how the myriad distinctive aspects of Etruscan culture which suggested an exogenous origin were in fact derived from the antecedent Bronze Age societies of Tuscany.

Ancient DNA extraction is now allowing scholars to map the change in frequencies of genetic markers of archaeologically known groups as a function of both space and time more broadly. **I think one can safely see that there are more perturbations, fluctuations, and [turnovers][11], than any pots-not-people model could predict**. On the specific issue of [lactase persistence][12] it is almost certainly a genetic novelty in Eurasia which arose over the last 10,000 years in a co-evolutionary fashion with animal husbandry. The [genomes][13] of modern Europeans suggest this, but [we have confirmation][14] from ancient DNA extraction as well. A rise in frequency of a particular allele does not entail a replacement of one population with another; lactase persistence today can exhibit a great deal of variance as a function of geography and ecology because its frequency no doubt responds to local selective pressures. But, in concert with other DNA data (mostly maternal lineages) as well as a fresh look at evidence of cultural discontinuity and rapid pulses of colonization in late Paleolithic and early Neolithic Europe, one must be open to the possibility that the spread of animal husbandry, copious raw milk consumption, and an aggressive and fecund population, were all concurrent processes which were tightly interlocked in some causal sense.

An aspect of this story which I am fuzzy and weak on is the archaeology. You likely know nearly as much about the [Linear Pottery Culture][15] as I do. It seems though that this cultural-complex brought agriculture deep into the heart of Central Europe ~7,000 years ago, and there are clear signs that its origin was to the southeast, from the Eastern Mediterranean region. L. L. Cavalli-Sforza’s [‘demic diffusion’][16] model which argued for the expansion of Neolithic farmers from the Middle East into Paleolithic Europe seemed to suggest that it occurred through a ‘[wave of advance][17]’ impelled by endogenous population growth and gradual migration. **The model as reported by **_**Der Spiegel **_**seems at some variance with this.** Instead of a gradual advance it seems that there may have been periodic pulses and explosions of demographic advance. Using the historical examples we have this should not be particularly surprising. Overlain atop the reality of an inexorable push across the ‘frontier’ in both North America and China by the colonizing peoples I alluded to earlier it is important to remember that there were periodic punctuations of gradualism by bursts of mass colonization, displacement, and relocation. The migration out of overpopulated New England to the Great Lakes and Upper Midwest in the early 19th century, the retreat to the south by the Han Chinese after the collapse of their first dynasty and the conquest of the north by barbarians. Both of these are examples of the explosive process in demographics and migration which can revolutionize the cultural landscape within a generation or two. From the data that the archaeologists have collected this seems to have occurred with the expansion of agricultural society in Central Europe as well, as the Linear Pottery Culture and its descendants proceeded in fits & starts.

Unfortunately as this is the domain of prehistory we won’t ever know in concrete terms exactly what occurred. In the _Der Spiegel _piece they report that the agriculturalists had a 500 year pause. Why? If demic diffusion was the primary dynamic through which they expanded there should be no pause. But we can think of a host of scenarios. Perhaps the Middle Eastern cultural toolkit had reached its natural outer boundary, and it was here that the tide turned to the indigenous Paleolithic societies of Europe, which maintained an advantage in the north because of the lack of the adaptability of southerners to new conditions. Humans can be stubbornly conservative in their ways. It is famously asserted that the Norse of Greenland did not adapt to a more inclement regime, and so went extinct (or, possibly evacuated to Iceland). The adoption of potatoes and other productive and useful crops among European peasants was retarded by their instinctive conservatism. We need not imagine a scenario where Paleolithic hunters and gathers would _naturally _wish to take up the hoe. Nor is it plausible that the agriculturalists would wish to refashion their tried & tested traditions so as to push the outer boundary of their [limes][18].

But all things must change. Something happened, and the agriculturalists shifted the _modus vivendi_, and the hunter-gatherers gave way. There are detailed historical processes which can give us insight as to how such long-held boundaries could rapidly collapse. Europeans had circumnavigated Africa by 1500, and had had factories and trading posts around the continent’s fringe for over 400 years by the late 19th century. But deep into the 1800s the European presence in Africa was marginal. By 1914 the continent was divided into European zones of control. What happened in the space of a few decades? [Quinine][19] and machine guns. The biological barrier to Europeans fell away, and the military superiority was amplified by orders of magnitude. What could have occurred in an analogous fashion in Central Europe? The combination of a mutation for lactase persistence and animal husbandry may have resulted in rapid population growth, leading to densities which precipitated the outbreak of an epidemic. A reduction in population may have had much greater impact on the less numerous and resistant hunter-gatherers. Additionally the economic changes wrought by animal husbandry may have allowed for a scaling up of the organization of war. The Mongol Empire exploded onto the scene in mere decades to sweep across most of Eurasia. Why couldn’t something similar plausibly have occurred in Central Europe on a much smaller scale 7,000 years ago?

Ultimately we’ll never know the details. But in constructing our plausible scenarios for prehistory I suspect that we moderns have a bias toward viewing pre-literate societies as usually small-scale, at best simple chiefdoms. I believe this is a false model, and that there was a non-trivial level of scalability possible among pre-literate societies. Going back to the Mongol example, I see no reason why the initial _existence_ of their polity necessitated literacy, though it may have been essential for its administration and _perpetuation_. Cultural forms likely marched with confederacies and were driven forward by warlords. This would easily explain the punctuated pattern of the spread of agriculture, as the rise and fall of states has a somewhat spasmodic and periodic character.

Finally, **I want to emphasize that the **_**Der Spiegel **_**piece verges on a maximalist position which I am not comfortable with**. There is much we don’t know, and I am in no hurry to replace one tired and dogmatic orthodoxy with another. Because the article was translated from German into English I can understand that that is responsible for the artlessness of some of the assertions. But phrases such as “There was no interbreeding between the intruders and the original population” from a German magazine really makes me think they’re suggesting that there were Stone Age [Nuremberg Laws][20]. Ethnic separation and differentiation was a reality among many ancient peoples, but so was intermarriage and assimilation. I am aware of the starkness of some of the DNA analyses, which suggest disjoint frequencies across the two populations, **but the results are far too spotty at this point to make definitive assertions.**

**Note:** The [accompanying map][4] is worth perusing.

(referral credit, [Steve Sailer][21])

_Image Credit: Wikimedia Commons_


[1]: http://blogs.discovermagazine.com/gnxp/files/2010/10/800px-European_Middle_Neolithic.gif (800px-European_Middle_Neolithic) [2]: http://www.spiegel.de/international/zeitgeist/0,1518,723310,00.html [3]: http://blogs.discovermagazine.com/gnxp/2010/05/say-it-with-me-volkerwanderung/ [4]: http://www.spiegel.de/international/zeitgeist/bild-723310-141465.html [5]: http://coa.sagepub.com/content/26/4/411.short [6]: http://blogs.discovermagazine.com/gnxp/2010/07/the-anglo-revolutions/ [7]: http://www.amazon.com/exec/obidos/ASIN/0300119933/geneexpressio-20/ [8]: http://blogs.discovermagazine.com/gnxp/2008/03/patterns-of-admixture-in-latin-american-mestizos/ [9]: http://www.gnxp.com/blog/2010/01/how-chinese-relate-to-each-other-and.php [10]: http://blogs.discovermagazine.com/gnxp/2010/03/the-science-of-human-history-as-written-by-herodotus/ [11]: http://blogs.discovermagazine.com/gnxp/2009/09/saami-not-descended-from-swedish-hunter-gathers/ [12]: http://en.wikipedia.org/wiki/Lactose_intolerance [13]: http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1000491 [14]: http://blogs.discovermagazine.com/gnxp/2010/04/ancient-swedes-were-lactose-intolerant/ [15]: http://en.wikipedia.org/wiki/Linear_Pottery_culture [16]: http://en.wikipedia.org/wiki/Demic_diffusion [17]: http://digital.library.adelaide.edu.au/dspace/handle/2440/15125 [18]: http://en.wikipedia.org/wiki/Limes [19]: http://en.wikipedia.org/wiki/Quinine#History [20]: http://en.wikipedia.org/wiki/Nuremberg_Laws#The_Laws [21]: http://isteve.blogspot.com/2010/10/are-europeans-all-middle-easterners.html [22]: http://feeds.feedburner.com/~r/DiscoverBlogs/~4/eG_KY67SVzI

URL: http://feedproxy.google.com/~r/DiscoverBlogs/~3/eG_KY67SVzI/

Leave a Reply

Your email address will not be published. Required fields are marked *