South American Lowlands Research Articles

Historical and ongoing hybridisation in Southern South American grassland species

Natural hybridisation in plants can impact genetic and morphological diversity, including the emergence of better-adapted new populations and the potential extinction of some lineages involved in this intricate process. Under progressive global warming, species often need to migrate to newly suitable areas, which may be an additional challenge for species with low dispersal ability. Throughout the search for new environments, previously allopatric lineages can come into secondary contact and eventually hybridise if reproductive isolation is incomplete. Here, we focused on two taxa representing the natural herbaceous component of southern South American lowland grasslands. We aimed to evaluate the impact of contact zones and potential hybridisation on the evolutionary relationships and population dynamics. We used single nucleotide polymorphisms and morphological data of multiple individuals from allopatric and contact zones between taxa to shed light on hybridisation patterns and demographic scenarios. Our results indicated that the contact zones impact taxa’s genetic and morphological diversity, and each contact zone had different patterns of genetic diversity and morphology, constituting stable populations that potentially reflect hybridisation events occurring at distinct evolutionary times.

Wood of Qualea from the Piedra Chamana in-situ fossil forest (late Middle Eocene, Peru) and the comparative wood anatomy of Vochysiaceae and Myrtaceae

Summary A wood from a late Middle Eocene in-situ fossil forest in northern Peru shows affinity with Qualea (Vochysiaceae), a genus of South American lowland tropical trees, based on features including vestured pits, aliform-confluent to banded paratracheal parenchyma, and homocellular rays. Additional features suggest adaptation to dry conditions. The fossil is named as a new species within Qualeoxylon (Q. lafila). Vochysiaceae and sister-group Myrtaceae share features unique to Myrtales (vestured pits, intraxylary phloem) or common in the order (vessels generally solitary and in >1 diameter class, heterocellular rays) but in other ways are clearly differentiated. Vochysiaceae has narrow to very wide vessels with elaborated axial parenchyma and lacks most characters considered less specialized such as scalariform perforations. Myrtaceae generally has vessels with vasicentric tracheids, usually exclusively solitary, very narrow to wide, and often diagonally arranged, and includes taxa with less to more specialized features. Woods with elaborated paratracheal parenchyma and vessels wide to very wide occur in wet tropical forest environments in both families Erisma, Vochysia and Qualea/Ruizterania (Vochysiaceae) in the Neotropics and Syzygium (Myrtaceae) in the Asian tropics. The Eucalyptus spp. dominating open forests in Australia have typical myrtaceous features (including vasicentric tracheids) plus homocellular rays, whereas the eucalypt clade Angophora + Corymbia, occurring mainly in the northern, monsoonal regions of Australia, has both vasicentric tracheids and aliform to banded axial parenchyma. The fossil is an early record for Vochysiaceae and adds to indications that Vochysiaceae and sister-group Myrtaceae showed significant diversification by the late Paleogene.

Amazonian shamanic enquiry: formulaic composition and specialized discourse

AbstractThis article investigates the styles of enquiry involved in Lowland South American Amerindian shamanic and narrative discourse genres. The article argues in favour of the existence of an Amazonian mode of thinking strictly related to formulaic composition, commonly found in different verbal poetic genres and its contemporary transformations into written texts published as books by Amerindian researchers and narrators. Taking into account philosophical and anthropological discussions about speculative thinking, this study aims to revise the role of narrative verbal genres in Amerindian ethnology and its ontological backgrounds, as well as offering an alternative perspective on the contrast between writing and oral traditions. The article is based on translations of songs and testimonies collected among the Marubo of Western Amazonia.

Knowledge of the Sky among Indigenous Peoples of the South American Lowlands—First Archaeoastronomical Analyses of Orientations at Mounds in Uruguay

We analyzed, from a cultural astronomy perspective, the relationship between the orientations of five mound sites and different astronomical events in the lowland region of Uruguay. We found significant relationships between the orientations of the mounds and the Southern Cross/Milky Way and the full Moon during the winter solstice ca. 3000 years BP. These relationships, meanings and senses to different native peoples of South America were explored from the literature of travelers’ and naturalists’ chronicles, alongside the ethnohistorical, ethnographic and archaeological literature. In particular, we highlighted the link among those peoples of the area of the Southern Cross/ Milky Way with a mythical Ñandú (Rhea americana). Such an interpretation has allowed us to raise the possibility that we are being faced with the integration of knowledge of the sky in the form of the social construction of inhabited space and the configuration of the landscape.

Large condor (Aves, Cathartidae) from the Late Pleistocene of Buenos Aires Province, Argentina

ABSTRACT The fossil record of condors in South America is relatively extensive. However, fossil specimens from the late Pleistocene of Argentina are still very scarce. Here, we describe fragmentary remains of a large sized cathartid of the condor lineage. The new specimen is represented by an incomplete ulna, radius and metacarpal belonging to the Lujanian (Late Pleistocene) of San Pedro locality, Buenos Aires, Argentina. Its large size (it is among the largest cathartids reported up to the date) and some anatomical details indicate that it belongs to a previously unrecognised taxon. The new specimen reinforces previous proposals indicating a high diversification of condors at South American lowlands, and indicates that the Pleistocene history of the clade is far from being satisfactorily known. The extinction of giant scavenger birds in South America may be not only related to the extinction of their food resources (i.e., megafauna) but also to ecological constraints that characterise large-sized birds.

Ben Nobbs-Thiessen. Landscape of Migration: Mobility and Environmental Change on Bolivia’s Tropical Frontier, 1952 to the Present.

The eastern lowlands of Bolivia, almost in the center of the South American continent, appear to be one of the most isolated places in the world, far from foreign influences. Ben Nobbs-Thiessen’s Landscape of Migration: Mobility and Environmental Change on Bolivia’s Tropical Frontier, 1952 to the Present shows us this is not at all the case. The author delineates a world of transnational penetration in the second half of the twentieth century that transformed the subtropical lowland region as a producer of cotton, soybeans, beef, and dairy goods. It was a period during which people from many parts of the world streamed into the South American lowlands, cutting forest to plant crops, mostly for export. Mennonite migrants from Mexico and Canada, Okinawans and Japanese from the Pacific region, and Andean migrants from the Bolivian highlands achieved the conversion from forest to fields in two generations, with an assist from the...

Demonstration of local adaptation in maize landraces by reciprocal transplantation.

Populations are locally adapted when they exhibit higher fitness than foreign populations in their native habitat. Maize landrace adaptations to highland and lowland conditions are of interest to researchers and breeders. To determine the prevalence and strength of local adaptation in maize landraces, we performed a reciprocal transplant experiment across an elevational gradient in Mexico. We grew 120 landraces, grouped into four populations (Mexican Highland, Mexican Lowland, South American Highland, South American Lowland), in Mexican highland and lowland common gardens and collected phenotypes relevant to fitness and known highland‐adaptive traits such as anthocyanin pigmentation and macrohair density. 67k DArTseq markers were generated from field specimens to allow comparisons between phenotypic patterns and population genetic structure. We found phenotypic patterns consistent with local adaptation, though these patterns differ between the Mexican and South American populations. Quantitative trait differentiation (Q ST) was greater than neutral allele frequency differentiation (F ST) for many traits, signaling directional selection between pairs of populations. All populations exhibited higher fitness metric values when grown at their native elevation, and Mexican landraces had higher fitness than South American landraces when grown in these Mexican sites. As environmental distance between landraces’ native collection sites and common garden sites increased, fitness values dropped, suggesting landraces are adapted to environmental conditions at their natal sites. Correlations between fitness and anthocyanin pigmentation and macrohair traits were stronger in the highland site than the lowland site, supporting their status as highland‐adaptive. These results give substance to the long‐held presumption of local adaptation of New World maize landraces to elevation and other environmental variables across North and South America.

A visual legacy: William Crocker’s ethnographic archive

Dr William Crocker began field research with the Canela (Maranhão state, Brazil) in 1957 and continued to do so intermittently until 2011 – a total of more than 54 years in an unprecedented long-term commitment to a field research programme in social anthropology. As soon as he arrived among the Canela, he began intensive documentation of their life. Photography and film played a major part in his observations and his use of these media proved extremely innovative in ethnographic study. Crocker produced one of the most detailed and accurate sets of visual documents about Lowland South American community life ever collected. This visual essay surveys this important ethnographic archival data (film footage, fields notes and photographs) and briefly analyses his visual enterprise, discussing the circumstances under which the images were taken, the ideas which informed them, and the general methods employed in making them. An interview I conducted with Crocker (2015) enriches our understanding of the collection.

Patterns and controls of carbon dioxide concentration and fluxes at the air–water interface in South American lowland streams

Patterns and controls of carbon dioxide concentration and fluxes at the air–water interface in South American lowland streams

Hunter-gatherer Mobility Analysed Through δ18O in the Patchy Environment of the Paraná Valley, South American Lowlands

ABSTRACT In this study we analyse the mobility of complex hunter-gatherers in the Lower Paraná wetland (South America) through δ18O values. To do this, we characterise the isotopic composition of water and bioapatite of stenoic and sedentary species from the region and the surrounding Pampa plain, and then we compare them with those obtained in human bones recovered at local archaeological sites. The results show that humans appear to have developed spatial stability strategies within certain areas, which is consistent with archaeological models of social circumscription among these pre-Columbian populations. Other finding of this study shows that any organism that moves along the middle and lower Paraná valley will not present differences in its δ18O values, but small transverse movements will produce significant variations, which relativises to some degree, the concept of ‘local’ and ‘non-local’ in the region. This study also addresses the methodological problems related to the characterisation of δ18O values in irregular environments, highlighting the importance of developing baselines based on local biocenoses.

Cosmo-Logics in Contemporary Lowland South America

This work is an attempt to introduce a comparison of the deep logics articulating cosmovisions and cosmologies among indigenous groups in the Lowlands of South America. We are particularly interested in describing the current state and recent past of these knowledge systems, but also connecting them to the distant past. We seek to leave aside an anecdotic comparative approach focused on isolated elements, and it is not our intention to build conjectural narratives of the links among these ways of conceiving the world. Instead, we wish to focus on analysing the common underlying logics that account for the organising principles of these cosmovisions and cosmologies, related to their relational and political nature. International works very often identify the South American Lowlands with Amazonia and here we would like to correct this and include examples from Patagonia on an equal footing with those from Chaco.

Plastome genomics in South American maize landraces: chloroplast lineages parallel the geographical structuring of nuclear gene pools.

The number of plastome sequences has increased exponentially during the last decade. However, there is still little knowledge of the levels and distribution of intraspecific variation. The aims of this study were to estimate plastome diversity within Zea mays and analyse the distribution of haplotypes in connection with the landrace groups previously delimited for South American maize based on nuclear markers. We obtained the complete plastomes of 30 South American maize landraces and three teosintes by means of next-generation sequencing (NGS) and used them in combination with data from public repositories. After quality filtering, the curated data were employed to search for single-nucleotide polymorphisms, indels and chloroplast simple sequence repeats. Exact permutational contingency tests were performed to assess associations between plastome and nuclear variation. Network and Bayesian phylogenetic analyses were used to infer evolutionary relationships among haplotypes. Our analyses identified a total of 124 polymorphic plastome loci, with the intergenic regions psbE-rps18, petN-rpoB, trnL_UAG-ndhF and rpoC2-atpI exhibiting the highest marker densities. Although restricted in number, these markers allowed the discrimination of 27 haplotypes in a total of 51 Zea mays individuals. Andean and lowland South American landraces differed significantly in haplotype distribution. However, overall differentiation patterns were not informative with respect to subspecies diversification, as evidenced by the scattered distribution of maize and teosinte plastomes in both the network and Bayesian phylogenetic reconstructions. Knowledge of intraspecific plastome variation provides the framework for a more comprehensive understanding of evolutionary processes at low taxonomic levels and may become increasingly important for future plant barcoding efforts. Whole-plastome sequencing provided useful variability to contribute to maize phylogeographic studies. The structuring of haplotype diversity in the maize landraces examined here clearly reflects the distinction between the Andean and South American lowland gene pools previously inferred based on nuclear markers.

Species diversification in the lowlands of mid-latitude South America: Turnera sidoides subsp. carnea as a case study.

The lowlands of mid-latitude South America comprise complex temperate ecoregions characterized by a unique biodiversity. However, the processes responsible for shaping its species diversity are still largely unknown. Turnera sidoides subsp. carnea is a variable subspecies occurring in the lowlands of northeastern Argentina and Uruguay, extending to southern Paraguay and Brazil. It constitutes a good model to perform evolutionary studies. Here we used an integrative approach to understand the process of diversification within this subspecies and to increase the knowledge concerning patterns and processes responsible for shaping the species diversity in the temperate lowlands of South America. The results provided strong evidences that this subspecies is an autopolyploid complex per se, being in an active process of intrasubspecific diversification. Morphological and genetic data show that the diversity of T. sidoides subsp. carnea is in congruence with the great past and present abiotic and biotic variability of the mid-latitude South American lowlands. The evolutionary history of this subspecies is consistent with past fragmentation and allopatric differentiation at diploid level. Geographic isolation and local adaptation would have promoted strong morphological, ecological, and genetic differentiation, resulting in two morphotypes and different genetic groups indicative of incipient speciation.

Linajes paternos autóctonos de Gran Chaco analizados con microsatélites

El Gran Chaco es uno de los biomas de las Tierras Bajas sudamericanas más recientemente poblados por los seres humanos, ha mantenido su diversidad etnolingüística y muestra evidencias de la existencia de contactos interétnicos. El objetivo de este trabajo es reconocer estructuración genética en la fracción nativa de los linajes paternos en las poblaciones chaqueñas, para lo cual se analizaron 116 individuos de poblaciones wichi, toba, chorote y mocoví de Argentina y lengua y ayoreo de Paraguay. Se identificaron los haplogrupos paternos a través de AFLP y posteriormente se determinaron los haplotipos basados en 17 microsatélites del cromosoma Y en los individuos poseedores de linajes nativos. Se agregaron 166 individuos del NOA para comparaciones regionales. Se estimaron frecuencias haplotípicas e índices de fijación. Se construyeron redes medianas y se evaluó la correlación entre las distancias geográficas y genéticas. Se realizaron Análisis de Coordenadas Principales, y se calcularon las posibles barreras genéticas (áreas geográficas donde la diferenciación genética entre poblaciones adyacentes es mayor). Se obtuvieron 167 haplotipos únicos y 43 haplotipos compartidos para las poblaciones de Gran Chaco y NOA. Las distancias FST y el análisis de autocorrelación espacial muestran estructura geográfica de aislamiento por distancia y 3 barreras que separan a tobas de Salta, lengua y ayoreo de Paraguay y mocovíes de Chaco, esperable ya que estas dos últimas son poblaciones que están geográficamente más distantes. Al agregar las muestras del NOA las barreras antes encontradas se mantienen, pero no se evidencian barreras entre las poblaciones de NOA y Gran Chaco, sugiriendo conexiones entre ambas regiones.

Landscapes variability and the early peopling of the inter-Andean Magdalena Valley, Colombia (South America)

The Magdalena River is the longest inter-Andean river in Northern South America. We focus on the middlesection calling attention to the implication of a geoarchaeological approach to understanding the role of depositional and erosional processes over time in the preservation and destruction of archaeological sites. Most likely the majority of the earliest Preceramic deposits - predating ca 12,900 BP - left in ancient shores and terraces, were erased or buried. Archaeological early remains are recorded on the alluvial paleo-terraces and piedmont hillslopes of the lowlands throughout the Pleistocene/Holocene Transition, during and after the El Abra Stadial - equivalent to the Younger Dryas period (ca. 12,900–11,700 cal BP). From the Terminal Pleistocene through the Middle Holocene specialized hunter-gatherers occupied floodplains and alluvial fan surfaces, as well as the relict high terraces remnants. The presence of industries with bifacial tools, - such as triangular stemmed points, and pressure retouched well finished tools (plano-convex scrapers) - occurred only throughout preceramic times. Climatic changes (above all precipitation variability), vegetation belt shifts and volcanism have affected geomorphic shifts in the lowlands of the Magdalena Valley. These changes are primarily responsible for the limited evidence of preceramic occupations. The early archaeological record is a dependent variable in the larger context of an evolving landscape. This relationship is critically important in evaluating the importance of the Magdalena Valley in the early settlement of the Northwest South American lowlands.

Las poblaciones indígenas prehispánicas del río Paraná Inferior y Medio

En este trabajo se sintetiza y discute el estado actual del conocimiento en la arqueología del río Paraná en Argentina, con especial énfasis en los estudios sistemáticos que nuestro equipo de investigación viene desarrollando desde hace más de 10 años en el Delta Superior, sudoeste de la provincia de Entre Ríos. Como resultado de las investigaciones se prospectó un amplio sector del área de estudio, se registraron más de 80 sitios arqueológicos, de los cuales se excavaron ocho. A través de la conformación de un grupo interdisciplinario, se aportó información relevante en temas tales como la cronología de las ocupaciones humanas, el uso de los recursos faunísticos y botánicos, las prácticas de producción y uso de la alfarería y la caracterización de las prácticas mortuorias. A partir de la información geoarqueológica y arqueobotánica se confirmó la génesis antrópica de las construcciones monticulares o cerritos y la presencia de horticultura de maíz, porotos y zapallo. También se evaluó la existencia de un bajo nivel de jerarquización social (ya mencionado en las primeras crónicas del siglo XVI) en las poblaciones asociadas con la entidad arqueológica Goya-Malabrigo, la que podría ser una derivación de la expansión meridional de los arawak. Finalmente, se abordó el estudio de la dispersión de los guaraníes y los modos de interacción con las poblaciones locales. En suma, los avances en las investigaciones de la última década muestran un panorama más complejo que integra la historia indígena local a procesos adaptativos generales ocurridos a lo largo de las Tierras Bajas sudamericanas.

Arqueología de los ríos Pilcomayo, Bermejo y Paraguay

Los ríos Paraguay, Pilcomayo y Bermejo son los principales protagonistas del aporte hídrico y sedimentario de la cuenca del Plata y constituyen enclaves estratégicos para comprender el poblamiento y dinámica poblacional de las tierras bajas sudamericanas. Este artículo tiene por objetivo aportar al conocimiento del pasado histórico de estos importantes cursos de agua, desde el momento en que se registran las primeras evidencias de ocupación humana, basadas en el análisis de manifestaciones culturales y biológicas, y de otros rasgos particulares resultantes de la construcción del paisaje en este sector de la cuenca del Plata. Para dar cuenta de la variabilidad arqueológica regional se propone un ordenamiento que articula criterios ecológicos, culturales e históricos. Por ello distinguimos sectores que denominamos Pilcomayo y Bermejo andino pedemontano; Pilcomayo y Bermejo chaqueño y sector Río Paraguay al que hemos diferenciado en superior (nacientes), medio, inferior y confluencia. En estos últimos tramos intervienen los grandes abanicos del Pilcomayo y Bermejo y el área de la confluencia Paraná ? Paraguay, que están culturalmente relacionados. La fuente de información arqueológica utilizada proviene de las investigaciones realizadas por nuestro equipo en la región chaqueña y de la información disponible en la bibliografía, la cual, en un esfuerzo de síntesis, integramos desde la óptica chaqueña y a la luz de las últimas investigaciones regionales. A lo largo de estos tres grandes ríos se destaca la interacción de diversos grupos humanos que capitalizaron el recurso de manera particular. No sólo como elemento vital, sino también por su importancia como proveedor de alimentos, factor de movilidad y comunicación. A lo largo de la sectorización espacial y temporal propuesta daremos cuenta del aprovechamiento de geoformas naturales como los albardones, la producción intencional de elevaciones monticulares y otras obras utilizadas tanto para la protección de desbordes como para almacenar y ¨cosechar¨ agua. Asimismo, las distintas estrategias de movilidad, migración, expansión e intercambio se han articulado de manera compleja dentro del repertorio de resoluciones de estos pueblos a lo largo de su historia. Esto ha cristalizado en el registro arqueológico de organizaciones diferenciales ya sea a través de sociedades pescadoras con movilidad reducida y amplias redes de interacción; otras con énfasis en la caza, pesca y recolección con alta movilidad residencial, o sociedades agropastoriles con marcado grado de sedentarismo que incluyeron el cultivo, en mayor o menor escala, entre sus actividades económicas.

Этноботаника Южной Америки к востоку от Анд в трудах миссионеров-иезуитов

Этноботаника Южной Америки к востоку от Анд в трудах миссионеров-иезуитов

The Piedra Chamana fossil woods (Eocene, Peru), II

ABSTRACTThis contribution presents descriptions of 14 fossil woods from the Piedra Chamana Fossil Forest in Peru, an assemblage of fossil woods and leaves dated at 39 Ma (late Middle Eocene). It is part two of the descriptions of the non-monocot angiosperm fossils from the site (see Woodcock et al. 2017). The woods are assigned to the subfamilies Bombacoideae, Bombacoideae/Malvoideae, Byttneroideae, Grewioideae, and Sterculioideae of Malvaceae and the families Melastomataceae, Muntingiaceae, Rubiaceae, Rutaceae, and Sapindaceae. Malvalean taxa make up around one-third of the wood types. Many of the woods are identifiable to modern-day genera or groups, including genera with species counted among the hyperdominant trees of the New World forests. Represented vegetation types include mixed freshwater swamp with Avicennia, seasonally flooded forest, and lowland tropical forest with a dry aspect. The assemblage shows floristic similarities to extant South American lowland tropical forest, particularly the seasonally flooded forests growing along white water rivers (várzea); however, the dry forest association has a less clear analog in the present-day tropics.

Nuevos aportes a la bioarqueología del Gran Chaco meridional (Argentina)

Las investigaciones bioantropológicas más recientes realizadas en el Gran Chaco meridional contribuyen a revertir el estado de desconocimiento que caracterizaba a las poblaciones humanas prehispánicas de esas latitudes. En esta oportunidad se presentan los resultados del análisis de los restos humanos exhumados en el sitio arqueológico El Pelícano (SChaGüe 2.0) el cual se encuentra en vinculación con una laguna que forma parte de los meandros del antiguo cauce del Río Bermejo (Argentina). La datación radiocarbónica de los restos involucrados estableció una antigüedad de 410±40 años 14C AP (LP3165). Se pudo constatar la presencia de dos individuos adultos, de sexo masculino y femenino con estaturas 166,43cm - 172,97cm y 152,88cm - 160,32cm, respectivamente. Del análisis paleopatológico se descartan indicadores de stress metabólico y ocupacional, no obstante se detectaron signos de periodontitis, caries, granulomas y pronunciado desgaste evidenciando consumo de alimentos con características abrasivas. Estos resultados permiten introducir nueva información en una región prácticamente inexplorada en términos arqueológicos y contribuye a la discusión de cambio y continuidad arqueológica etnográfica de las Tierras Bajas sudamericanas.