As the reader might have guessed by now, one of the theories that I find most attractive in linguistic geography is the opposition between spread and mosaic zones. In the form developed by Nichols, this theory posits that some areas – in general, broad plains with few natural barriers – are prone to the dispersal of single languages or families, whereas other regions (islands, mountain chains) tend to accumulate isolates and small families. Not only specific languages stretch over the spread zones, but also linguistic features. Just look at Eurasia and you will see layer over layer of prehistoric (and more recent) spreads. There is a long East-West axis that served as a corridor for the Indo-European, Uralic, Turkic and Mongolic languages, pretty much along the same steppe that brought Attila and Genghis Khan to the doors of Europe. All the language families in this area also share similar features – as opposed, for example, to the languages of the Caucasus or to the Sino-Tibetan family. The big question is: what are the archaeological correlates of a spread zone? The answer is in the horizon!
Archaeological horizons are geographically extensive phenomena – a ceramic style, a particular form of architecture, or iconography – whose spread happened very fast but whose persistence was often relatively short-lived. If we are trying to identify the periods when some large language families reached their territorial zenith, then we must look for archaeological horizons rather than for very localised cultures. Moreover, it is likely that cultural horizons they corresponded to linguistic spread zones, whereas mosaic zones should be characterised by a myriad of local traditions. Curiously, in South America, the spread zones are very different from the Eurasian case – partly due to the absence of extensive grassy plains with no obstacle to movement (the Argentinian pampas being the obvious exception, although they are not as important a communication route as the Eurasian steppe that connects the continent’s long East-West axis). Instead, the South American spread zones are large river systems (the Amazon and the La Plata Basins) and the Andean cordillera. Yes, mountains are spread zones in South America!
On the Andean side of the debate, the most important question pertains to when the largest language families in the region – Quechua and Aymara – were diffused. Once thought to be closely related in a “Quechumaran” family, the resemblance between the two is now known to be the result of extensive contact. Quechua is much more widespread than Aymara, partly because it was adopted as the language of the Inca empire (although it was already used over a broad territory even before that), but both functioned as linguae francae in different parts of the Central Andes. As correctly pointed out by Paul Heggarty, Quechua and Aymara must have spread during the Early and Middle Horizons of Andean Prehistory (the Late Horizon corresponds to the Inca expansion, but Quechua was already widespread by then). These are periods when shared architecture and/or iconography diffused throughout the coast and the cordillera – presumably, hand in hand with new ideas and, of course, languages. The Andean Horizons are separated by periods of fragmentation, called the intermediate periods, when local cultures flourished.
The Early Horizon, around 900 B.C., is the time of Chavín de Huantar – a labyrinthic pilgrimage ceremonial centre in the highlands once thought to be the “mother culture” of the Andes, but now known to be just one manifestation of a broadly shared tradition. For Heggarty, this is when Aymara started to spread. The reasoning behind that is that there are “islands” of Aymara, as well as place names, in what is now a “sea” of Quechua (including in the region around Chavín), i.e. Aymara must have spread first. I have some doubts about this hypothesis, especially because the family seems a bit shallow (the two other languages, Jaqi and Aru, spoken in central Peru, are not that different from the southern Aymara varieties). However, I admit that it is the most parsimonious explanation. This leaves us with the Middle Horizon as the time when Quechua first expanded. Starting around A.D. 600, the Middle Horizon is the time when two major centres made their influence felt over a wide sphere in the Andes: to the North, Wari, and to the South, Tiwanaku. Although the latter is usually associated with Aymara in most people’s imagination, we know that this language only arrived recently in the region. Could the original one have been Quechua? The linguistic diversity in this area points to other possibilities, including Uru, Chipaya and Puquina. Finally, with the onset of the Late Horizon by A.D. 1450, the Incas continued to propel the expansion of Quechua, as did the Spanish after the conquest. What is important to keep in mind is that there are clear correlates of a linguistic spread zone in the archaeological horizons of the Andes.
Let’s move now to the East, to the lowlands of South America. Here, there are two related phenomena whose continental scale grants them the status of archaeological horizons: in the Amazon river, the Polychrome Tradition; in the other large rivers and Atlantic coast, the (distantly) related TupiGuarani Tradition. Starting around 500 B.C., the TupiGuarani Tradition spread from southwestern Amazonia, bringing with it virtually identically decorated ceramics, among other traits. The distribution of the sites and their chronology coincide almost perfectly with the historical extent and depth of the TupiGuarani language family. Thus, unlike in the Andean case, here we know exactly with which languages to associate an archaeological culture. The issue with the Amazon Polychrome Tradition is not so simple. Starting around A.D. 1000 or maybe a few centuries earlier, this tradition rapidly spread over the basin. Some suggest it might also be associated with TupiGuarani languages, based on the fact that the historical Kokama and Omagua, who spoke languages of that family, were still producing similar designs during colonial times. I would really like that to be true, as it would confirm the Spread Zone nature of the main South American waterway. However, there are other groups producing similar pottery until the present, like the Shipibo-Conibo, who are Pano-speakers. Of course, the adoption of the pan-Amazonian polychrome designs does not necessarily imply the diffusion of a single language. However, because the Kokama and Omagua languages apparently result from an ancient TupiGuarani-based lingua franca, I would take that as a serious hypothesis.
Following on the tradition of showing a little bit of the languages in question, the examples above offer a brief comparison of some widely spaced Quechua and TupiGuarani languages. I have selected sentences with similar structures, though I could hardly find identical ones. The Quechua of Pastaza and Napo, spoken in the Ecuadorian Amazon, and the Quechua of Santiago del Estero, spoken in northwestern Argentina, are separated by over 3,000 km. Kayabi, spoken near the Xingu river, southern Amazon, and Mbyá, spoken in southern Brazil and neighbouring Argentina and Paraguay, are separated by nearly 2,000 km. Yet, the similarities are striking. Moreover, although the two families are completely distinct in terms of morphology (as expected form the west-east divide in South America), they tend to have simpler phoneme inventories and “easier”, more regular structures than many languages that remained in the mosaic zones (see a few examples of isolates and other South American families here). Quechua, in particular, has a regularity reminiscent of an artificial language. I would tentatively suggest that this is a characteristic of languages that succeed in disseminating over the spread zones.
What about the archaeological correlates of linguistic mosaic zones? As I said in a previous post, these tend to be areas rich in localised archaeological cultures. I have highlighted a few of them in the map at the beginning of this post. North- and southwestern Amazon are typical mosaic zones. Recently, the southern fringe of the Amazon has been shown to hide a myriad of archaeological sites with earthworks, ditches, enclosures and roads. Among these are the Geoglyphs of the state of Acre and the “Garden cities” of the Upper Xingu. The Llanos de Mojos, about which I wrote previously, is another example. However, these are very different archaeological cultures, and even within one of these regions there is enormous variety. Therefore, they are perfect correlates of linguistic mosaic zones: there is not a widespread ceramic style or other material trait over these areas, which is matched by their linguistic diversity.