Spatial Histories of the South American Borderlands

The Guerrero suspect terrane (western Mexico) and coeval arc terranes (the Greater Antilles and the Western Cordillera of Colombia): a late Mesozoic intra-oceanic arc accreted to cratonal America during the Cretaceous

Species delimitation and biogeography of the gnatcatchers and gnatwrens (Aves: Polioptilidae)

Influence of Peruvian flat-subduction dynamics on the evolution of western Amazonia

A multidisciplinary approach is used to analyze the Cenozoic uplift history of South America. Residual depth anomalies of oceanic crust abutting this continent help to determine the pattern of present‐day dynamic topography. Admittance analysis and crustal thickness measurements indicate that the elastic thickness of the Borborema and Altiplano regions is km with evidence for sub‐plate support at longer wavelengths. A drainage inventory of 1827 river profiles is assembled and used to investigate landscape development. Linear inverse modeling enables river profiles to be fitted as a function of the spatial and temporal history of regional uplift. Erosional parameters are calibrated using observations from the Borborema Plateau and tested against continent‐wide stratigraphic and thermochronologic constraints. Our results predict that two phases of regional uplift of the Altiplano plateau occurred in Neogene times. Regional uplift of the southern Patagonian Andes also appears to have occurred in Early Miocene times. The consistency between observed and predicted histories for the Borborema, Altiplano, and Patagonian plateaux implies that drainage networks record coherent signals that are amenable to simple modeling strategies. Finally, the predicted pattern of incision across the Amazon catchment constrains solid sedimentary flux at the Foz do Amazonas. Observed and calculated flux estimates match, suggesting that erosion and deposition were triggered by regional Andean uplift during Miocene times.

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Click to increase image sizeClick to decrease image size Acknowledgement We would like to thank both the editors of the Journal of Genocide Research for allowing us the opportunity to publish this work collectively, and the anonymous referees of the journal for their remarks, criticisms and comments. Notes See the discussion in Paul Boghossian, ‘The concept of genocide’, Journal of Genocide Research, Vol. 12, No. 1, 2010, pp. 69–80. The term was first used by Leo Kuper, Genocide: its political use in the twentieth century (New Haven, CT: Yale University Press, 1981), and reprised by Ben Kiernan, Blood and soil: a world history of genocide and extermination from Sparta to Darfur (New Haven, CT: Yale University Press, 2007). For a similar approach, see the special issue entitled ‘Les massacres aux temps des Révolutions’, in La Révolution française: Cahiers de l'Institut d'Histoire de la Révolution française, 3 (2011). Philip Dwyer and Lyndall Ryan, ‘The massacre and history’, in Philip Dwyer and Lyndall Ryan (eds.), Theatres of violence: massacre, mass killing and atrocity throughout history (New York: Berghahn Books, 2012), pp. xiii. Most indigenous perspectives are either North or South American. See, for example, Karl Jacoby, ‘“The broad platform of extermination”: nature and violence in the nineteenth-century American Borderlands’, Journal of Genocide Research, Vol. 10, No. 2, 2008, pp. 249–267. Jacques Semelin, Purify and destroy: the political uses of massacre and genocide, trans. Cynthia Schoch (New York: Columbia University Press, 2007); Semelin, ‘Du crime de masse’, in Thomas Ferenczi (ed.), Faut-il s'accommoder de la violence? (Paris: Complexe, 2000), pp. 375–391. Mark Levene and Penny Roberts (eds), The massacre in history (New York: Berghahn Books, 1999), pp. 1, 4, 5. See Keith Windschuttle, ‘The myth of frontier massacres in Australian history, Part II: the fabrication of the Aboriginal death toll’, Quadrant, November 2000, p. 18; and Ben Kiernan, ‘Australia's Aboriginal genocide’, Yale Journal of Human Rights, Vol. 1, No. 1, (2000), p. 52. See, for example, Alain Corbin, The village of cannibals: rage and murder in France, 1870, trans. Arthur Goldhammer (Cambridge, MA: Harvard University Press, 1992). As would argue Howard G. Brown, ‘Domestic state violence: repression from the croquants to the commune,’ Historical Journal, Vol. 42, No. 3, 1999, pp. 597–622. David A. Bell, The first total war: Napoleon's Europe and the birth of modern warfare (London: Bloomsbury, 2008), p. 168. The association between the ‘genocide’ in the Vendée and later twentieth-century totalitarian genocides reached its climax during the Bicentenary of the Revolution with the publication of Reynald Secher's Le génocide franco-français: la Vendée-Vengé (Paris: Presses universitaires de France, 1988). For a discussion of this debate see, Jean-Clément Martin, La Vendée et la Révolution. Accepter la mémoire pour écrire l'histoire (Paris: Perrin, 2007), pp. 61–85. Roger Chickering, ‘A tale of two tales: grand narratives of war in the age of revolution’, in Roger Chickering and Stig Förster (eds.), War in an age of revolution, 1775–1815 (Cambridge: Cambridge University Press, 2010), pp. 1–17. Arno J. Mayer, The Furies: violence and terror in the French and Russian revolutions (Princeton, NJ: Princeton University Press, 2000). On the Australian connection see Christine Wright, Wellington's men in Australia: Peninsular War veterans and the making of empire c.1820–40 (Basingstoke: Palgrave Macmillan, 2011). See, for example, Olivier Le Cour Grandmaison, Coloniser, Exterminer: Sur la guerre et l'Etat colonial (Paris: Fayard, 2005). Kiernan, Blood and soil. A. Dirk Moses (ed.), Empire, colony, genocide: conquest, occupation, and subaltern resistance in world history (New York: Berghahn, 2008).

The joint effect of the Andes as a geographical barrier and the Quaternary glaciations as promoters of genetic divergence remains virtually unexplored in southern South America. To help fill this knowledge gap, in this study we investigated the demographic history of Centris cineraria, a solitary bee mainly distributed in Patagonia. We used mitochondrial and nuclear markers and performed phylogeographical and dating analyses, adjusted spatio-temporal diffusion and species distribution models, and used Approximate Bayesian Computation to identify likely historical demographic scenarios. Our results revealed that during glacial periods the Andes represented a barrier due to the extent of the ice-sheets and the occurrence of unsuitable habitats, while interglacials allowed for gene flow across the Andes. Secondary contact between previously isolated lineages was evident across at least two low-altitude Andean areas, the northern one being a putative glacial refugium. Our findings also suggest that C. cineraria has persisted in situ in four periglacial refugia located along a north–south transect, congruent with the maximum extent of the ice sheet during the Greatest Patagonian Glaciation. As the first phylogeographical study of Patagonian insects, our work reveals that the interaction between Quaternary climatic oscillations and the Andes as a barrier was the main driver of the spatial and demographic history of C. cineraria.

The introduction of stable isotopes in archaeological research beginning in the 1970s produced a revolution in the ways that several key anthropological issues were studied, including early hominin subsistence, hunter-gatherer spatial organisation, origins and history of farming and pastoralist societies, migrations, and intraand inter-group social differentiation. As a tool suited for the quantitative reconstruction of palaeodiets, bone chemistry provided a new and independent line of evidence that was readily integrated into ongoing discussions based on archaeofaunal and palaeobotanical data (see van der Merwe, 1982; Ambrose, 1993). The impact that isotopic research has had in the field of archaeology is reflected in the ever-growing number of publications making use of isotopic analyses, and in the also growing number of volumes directed towards the integration of available results and perspectives of analysis (Sillen & Armelagos, 1991; Sandford, 1993; Bocherens et al., 1999; Ambrose & Katzenberg, 2000; Ambrose & Krigbaum, 2003; Koch & Burton, 2003; Staller et al., 2006).

The movement of viruses in aquatic systems is rarely studied over large geographic scales. Oceanic currents, host migration, latitude-based variation in climate, and resulting changes in host life history are all potential drivers of virus connectivity, adaptation, and genetic structure. To expand our understanding of the genetic diversity of Callinectes sapidus reovirus 1 (CsRV1) across a broad spatial and host life history range of its blue crab host (Callinectes sapidus), we obtained 22 complete and 96 partial genomic sequences for CsRV1 strains from the US Atlantic coast, Gulf of Mexico, Caribbean Sea, and the Atlantic coast of South America. Phylogenetic analyses of CsRV1 genomes revealed that virus genotypes were divided into four major genogroups consistent with their host geographic origins. However, some CsRV1 sequences from the US mid-Atlantic shared high genetic similarity with the Gulf of Mexico genotypes, suggesting potential human-mediated movement of CsRV1 between the US mid-Atlantic and Gulf coasts. This study advances our understanding of how climate, coastal geography, host life history, and human activity drive patterns of genetic structure and diversity of viruses in marine animals and contributes to the capacity to infer broadscale host population connectivity in marine ecosystems from virus population genetic data.

Many mechanisms have been proposed to explain broad scale spatial patterns in species richness. In this paper, we evaluate five explanations for geographic gradients in species richness, using South American owls as a model. We compared the explanatory power of contemporary climate, landcover diversity, spatial climatic heterogeneity, evolutionary history, and area. An important aspect of our analyses is that very different hypotheses, such as history and area, can be quantified at the same observation scale and, consequently can be incorporated into a single analytical framework. Both area effects and owl phylogenetic history were poorly associated with richness, whereas contemporary climate, climatic heterogeneity at the mesoscale and landcover diversity explained ca. 53% of the variation in species richness. We conclude that both climate and environmental heterogeneity should be retained as plausible explanations for the diversity gradient. Turnover rates and scaling effects, on the other hand, although perhaps useful for detecting faunal changes and beta diversity at local and regional scales, are not strong explanations for the owl diversity gradient.

During the late eighteenth century, Portugal and Spain sent joint mapping expeditions to draw a nearly 10,000-mile border between Brazil and Spanish South America. These boundary commissions were the largest ever sent to the Americas and coincided with broader imperial reforms enacted throughout the hemisphere. Where Caciques and Mapmakers Met considers what these efforts meant to Indigenous peoples whose lands the border crossed. Moving beyond common frameworks that assess mapped borders strictly via colonial law or Native sovereignty, it examines the interplay between imperial and Indigenous spatial imaginaries. What results is an intricate spatial history of border making in southeastern South America (present-day Argentina, Brazil, and Uruguay) with global implications. Drawing upon manuscripts from over two dozen archives in seven countries, Jeffrey Erbig traces on-the-ground interactions between Ibero-American colonists, Jesuit and Guaraní mission-dwellers, and autonomous Indigenous peoples as they responded to ever-changing notions of territorial possession. It reveals that Native agents shaped when and where the border was drawn, and fused it to their own territorial claims. While mapmakers' assertions of Indigenous disappearance or subjugation shaped historiographical imaginaries thereafter, Erbig reveals that the formation of a border was contingent upon Native engagement and authority.

ABSTRACTThis article examines the role of grassroots actors in regions of violent conflict where competing governance systems exists. Specifically, it focuses on those living in the borderlands of South America, where alternative forms of governance may be created in response to violence between state and criminal organizations. In this context, how can grassroots actors overcome protracted armed violence and establish new, legitimate forms of social governance? To explore this question, our methodology employs data triangulation, combining literature, news reports, and fieldwork data collected in two violence‐prone territories: the borderlands of Cúcuta (Colombia)/Táchira state (Venezuela) and Pedro Juan Caballero (Paraguay)/Ponta Porã (Brazil). We argue that grassroots actors can develop innovative and alternative governance structures that differ from those of the state and criminal groups. This research also contributes to the ongoing discussion about the agency of local actors in violent conflicts between nonstate actors and the state. The findings demonstrate that grassroots actors in violent border regions can actively transform conflicts and build peace, particularly in areas such as migration, security, health, and education.

Natives, Iberians, and Imperial Loyalties in the South American Borderlands, 1750–1800

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