Out of Amazonia: late-Holocene climate change and the Tupi–Guarani trans-continental expansion

The late Holocene expansion of the Tupi-Guarani languages from southern Amazonia to SE South America constitutes one of the largest expansions of any linguistic family in the world, spanning ~ 4000 km between latitudes 0°S and 35°S at about 2500 yr B.P. However, the underlying reasons for this expansion are a matter of debate. Here, we compare continental-scale palaeoecological, palaeoclimate, and archaeological datasets, to examine the role of climate change in facilitating the expansion of this forestfarming culture. Because this expansion lies within the path of the South American Low-Level Jet, the key mechanism for moisture transport across lowland South America, we were able to explore the relationship between climate change, forest expansion, and the Tupi-Guarani. Our data synthesis shows broad synchrony between late Holocene increasing precipitation and southerly expansion of both tropical forest and Guarani archaeological sites – the southernmost branch of the Tupi-Guarani. We conclude that climate change likely facilitated the agricultural expansion of the Guarani forest-farming culture by increasing the area of forested landscape that they could exploit, showing a prime example of ecological opportunism

Disease: A Hitherto Unexplored Constraint on the Spread of Dogs (Canis lupus familiaris) in Pre-Columbian South America

Although debate continues, there is agreement that dogs (Canis lupus familiaris) were first domesticated in Eurasia, spreading from there to other parts of the world. However, while that expansion already extended as far as Europe, China, and North America by the early Holocene, dogs spread into (and south of) the tropics only much later. In South America, for example, the earliest well attested instances of their presence do not reach back much beyond 3000 cal. BC, and dogs were still absent from large parts of the continent – Amazonia, the Gran Chaco, and much of the Southern Cone – at European contact. Previous explanations for these patterns have focused on cultural choice, the unsuitability of dogs for hunting certain kinds of tropical forest prey, and otherwise unspecified environmental hazards, while acknowledging that Neotropical lowland forests witness high rates of canine mortality. Building on previous work in Sub-Saharan Africa (Mitchell 2015) and noting that the dog’s closest relatives, the grey wolf (C. lupus) and the coyote (C. latrans), were likewise absent from South and most of Central America in Pre- Columbian times, this paper explores instead the possibility that infectious disease constrained the spread of dogs into Neotropical environments. Four diseases are considered, all likely to be native and/or endemic to South America: canine distemper, canine trypanosomiasis, canine rangeliosis, and canine visceral leishmaniasis caused by infection with Leishmania amazonensis and L. colombiensis. The paper concludes by suggesting ways in which the hypothesis that disease constrained the expansion of dogs into South America can be developed further

Pattern of extinction of the woolly mammoth in Beringia

Extinction of the woolly mammoth in Beringia has long been subject to research and speculation. Here we use a new geo-referenced database of radiocarbon-dated evidence to show that mammoths were abundant in the open-habitat of Marine Isotope Stage 3 (∼45–30 ka). During the Last Glacial Maximum (∼25–20 ka), northern populations declined while those in interior Siberia increased. Northern mammoths increased after the glacial maximum, but declined at and after the Younger Dryas (∼12.9–11.5 ka). Remaining continental mammoths, now concentrated in the north, disappeared in the early Holocene with development of extensive peatlands, wet tundra, birch shrubland and coniferous forest. Long sympatry in Siberia suggests that humans may be best seen as a synergistic cofactor in that extirpation. The extinction of island populations occurred at ∼4 ka. Mammoth extinction was not due to a single cause, but followed a long trajectory in concert with changes in climate, habitat and human presence

78,000-year-old record of Middle and Later Stone Age innovation in an East African tropical forest

The Middle to Later Stone Age transition in Africa has been debated as a significant shift in human technological, cultural, and cognitive evolution. However, the majority of research on this transition is currently focused on southern Africa due to a lack of long-term, stratified sites across much of the African continent. Here, we report a 78,000-year-long archeological record from Panga ya Saidi, a cave in the humid coastal forest of Kenya. Following a shift in toolkits ~67,000 years ago, novel symbolic and technological behaviors assemble in a nonunilinear manner. Against a backdrop of a persistent tropical forest-grassland ecotone, localized innovations better characterize the Late Pleistocene of this part of East Africa than alternative emphases on dramatic revolutions or migrations.peer-reviewe

Expanding the scope of Actualistic Taphonomy in Archaeological Research

This chapter presents the application of actualistic taphonomy to the study of one of the inorganic remains produced by hominins since 3 million year BP up to historical times: lithic artifacts. As rocks are among the most durable raw materials employed by modern humans and their ancestors, differential preservation has conferred a leading role in archaeological research upon lithic artifacts. Indeed, lithics -flaked artifacts in particular- are the proxy for culture or anthropic presence most commonly used by scholars all over the world. This artifact-human relationship promoted actualistic research on flintknapping in archaeology but no similar effort was devoted to assessing alternative non-cultural (i.e. taphonomic) sources for flaked stone objects. Even though actualistic studies have already shown that taphonomic processes may produce lithic pseudomorphs, this fact is only rarely considered in archaeological practice and research design. Furthermore, it is commonly assumed that human products are different enough from any natural specimen to be detected by lithic analysts. However, the current lack of knowledge on non-cultural flaking processes and their byproducts prevents their identification in the archaeological record, thus undermining the accuracy and reliability of archaeological interpretations. This paper illustrates the contribution of actualistic taphonomy to study the inorganic remains of the archaeological record and its critical role in assessing the cultural vs natural origin of lithic specimens in Fuego-Patagonia (South America). Naturalistic and experimental research on rockfall and trampling presented here suggests that the effects of these taphonomic processes result in pseudoartifacts that progressively incorporate to the regional archaeological record.Fil: Borrazzo, Karen Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; Argentin