Groups In South America Research Articles

Is it all Phacelia pinnatifida? Molecular delimitations and taxonomic revision of Phacelia sect. Glandulosae in South America based on ddRADseq

AbstractPhacelia sect. Glandulosae, with ca. 62 taxa, is the most diverse of the 11 sections of the genus Phacelia (Hydrophyllaceae). The family is largely restricted to North and Central America, but the genus Phacelia has an amphitropical distribution with nine species reported from western South America, five of which have been assigned to P. sect. Glandulosae. These species are found in arid to semi‐arid Andean habitats between 1000 and 5000 m a.s.l. Species delimitation has long been confounded for this plant group in South America by some degree of taxonomic chaos – lack of typifications, dozens of synonyms, different names used for the same taxon between different countries – and poor representation in molecular phylogenies. Here, we try to improve our understanding by employing a ddRADseq strategy to investigate phylogenetic relationships of all South American representatives of P. sect. Glandulosae based on a total of 33 sampled specimens. Both maximum likelihood and species tree inference analyses of the ddRADseq data resulted in a well‐resolved topology. All five species currently recognized in P. sect. Glandulosae in South America form a highly supported monophylum including P. nana, previously considered as belonging to P. sect. Euglypta. However, the currently recognized morphospecies form a clade with very short branch lengths indicating coalescence processes at the level of population, except for P. artemisioides, which is clearly sister to the rest. Additionally, different morphospecies and ecotypes are largely retrieved as poly‐ and/or paraphyletic. Based on these results and on re‐evaluation of the morphological characters traditionally used to delineate species within P. sect. Glandulosae, we argue that these characters are of limited diagnostic value. We recommend recognizing only two South American species within this section: polymorphic P. pinnatifida and its closely related sister species P. artemisioides. A revised formal taxonomy is provided.

Aspects of the reproductive biology of sympatric Myrtaceae: <i>Myrceugenia euosma</i> and <i>Siphoneugena reitzii</i> in southern Brazil

Background: The Myrtaceae family represents one of the most diverse groups in South America. Yet, there are few studies on their reproductive characteristics. Among the species with limited information on their reproductive behavior are Myrceugenia euosma (O. Berg) D. Legrand and Siphoneugena reitzii D. Legrand. Questions: What are the floral attractions and resources of M. euosma and S. reitzii for pollinators? Who are the pollinators of these species? What is the predominant reproductive system in both species? Studied species: M. euosma and S. reitzii, two sympatric Myrtaceae from southern Brazil. Study site and dates: Urubici, Painel, and Rio Rufino, Santa Catarina state, southern Brazil. November 2021 - February 2022. Methods: Information was obtained on morphological aspects, anthesis time, stigmatic viability, floral resources, structures attractive to visitors, olfactory testing, observation and identification of floral visitors, and reproductive system testing. Results: The flowers of M. euosma opens between 11 am and 17 pm (- 20 pm), with full opening occurring mostly at night; S. reitzii flowers open between 4 a.m. and 6 a.m., with a highest peak by 8 a.m. Flowers of both species have receptive stigmas until senescence. Pollen is the primary floral reward and the scent coming from the anthers combined with the floral display attract native bees and Apis mellifera, legitimate pollinators of both species. The lack of fruit development in the self-pollination tests support cross reproduction in both taxa. Conclusions: Both species exhibit traits consistent with melittophily syndrome and potential self-incompatibility. These results are essential for conservation efforts.

A Latin American Perspective on the Leuenberg Agreement

AbstractAmong the 104 churches signatory to the Leuenberg Agreement of 1973, which created ecclesial communion between Lutheran, Reformed, and United churches in Europe, are six churches from Latin America, five of them from the Southern Cone. This article reviews how the Protestant churches in the Southern Cone came to be signatories of the Leuenberg Agreement and its significance for their life and witness. Two elements in particular have proven significant over the years. The first is the theological and ecumenical platform the Leuenberg Agreement provided, which gave visibility to a phenomenon already taking place. The second is the fact that the Communion of Protestant Churches in Europe has a regional group in South America: this was the case almost from the beginning, which also poses an interesting theological and contextual challenge.

The genetic history of the Southern Andes from present-day Mapuche ancestry

The southernmost regions of South America harbor some of the earliest evidence of human presence in the Americas. However, connections with the rest of the continent and the contextualization of present-day indigenous ancestries remain poorly resolved. In this study, we analyze the genetic ancestry of one of the largest indigenous groups in South America: the Mapuche. We generate genome-wide data from 64 participants from three Mapuche populations in Southern Chile: Pehuenche, Lafkenche, and Huilliche. Broadly, we describe three main ancestry blocks with a common origin, which characterize the Southern Cone, the Central Andes, and Amazonia. Within the Southern Cone, ancestors of the Mapuche lineages differentiated from those of the Far South during the Middle Holocene and did not experience further migration waves from the north. We find that the deep genetic split between the Central and Southern Andes is followed by instances of gene flow, which may have accompanied the southward spread of cultural traits from the Central Andes, including crops and loanwords from Quechua into Mapudungun (the language of the Mapuche). Finally, we report close genetic relatedness between the three populations analyzed, with the Huilliche characterized additionally by intense recent exchanges with the Far South. Our findings add new perspectives on the genetic (pre)history of South America, from the first settlement through to the present-day indigenous presence.Follow-up fieldwork took these results back to the indigenous communities to contextualize the genetic narrative alongside indigenous knowledge and perspectives. VIDEO ABSTRACT.

DIVERSIDAD DE LOS ÉQUIDOS FÓSILES DE AMÉRICA DEL SUR Autores/as

The contemporary mammalian communities of South America were defined by the rise of the Isthmus of Panama and by the deep climatic oscillations during the Pleistocene. Horses are a conspicuous group of North American immigrant mammals that came to South America during the late Pliocene and did not survive the great megafauna extinction approximately twelve thousand years ago. The present study compiles updated data on the phylogeny, systematics and ecology of this group in South America. The first lineage is represented by the genus Equus, which appears in the Middle Pleistocene and presents anatomical features similar to those of a current horse. The second lineage is the species included in the genus Hippidion, which were horses with highly distinctive anatomical features that were first recorded in the late Pliocene. Both genera of horses include small (H. devillei, H. saldiasi, E. andium and E. insulatus) and large (E. neogeus and H. principale) forms, which dispersed in South America using two different routes. The possible model for this dispersal indicates that the small forms used the corridor of the Andes, while the larger horses dispersed along the eastern route and some coastal areas.

A terrestrial Internet from the quilombos: the transatlantic evolution of baobab from colonial to digital capitalism

ABSTRACT Based on ethnographic fieldwork, this article examines the origin and development of “Baobáxia,” a digital network for sharing community-produced content. Baobaxia emerged in “quilombos” (communities of run-away slaves’ descendents) in Brazil in the early 2000s and expanded to other marginalized groups in South America, Africa, and Europe. Our focus on the essential roles of baobab trees in this network raises the question of material resources sustaining the Internet and digital capitalism. Baobaxia turns out to be a “terrestrial Internet” that exposes the capitalist illusion of dematerialization and demonstrates a different approach to technology development amid the planetary environmental crises today. The analysis reveals the articulation of ancestral knowledge and new technologies in the building of Baobaxia, a network that is adaptive to local-geographical, ecological and infrastructural conditions and that supports community resistance, autonomy, and sustainability. The development of Baobaxia, historically rooted and future-oriented, is an enlightening grassroots experiment in exploring and sharing ways of making a world that may sustain life. Our study of the five-century transatlantic evolution of baobab challenges the often limited spatio-temporal framework in ethnographic research. We thus call for methodological openness to alternative perspectives from ethnographic interlocutors to guide academic understandings of the world.

Diversity of the fossil gomphotheres from South America

ABSTRACT The contemporary mammalian communities of South America were defined by the rise of the Isthmus of Panama and by the deep climatic oscillations during the Pleistocene. Gomphotheres are a conspicuous group of North American immigrant mammals that came to South America during the late Pliocene and did not survive the great megafauna extinction approximately twelve thousand years ago. The present study compiles updated data on the phylogeny, systematics and ecology of this group in South America. Both genera reached South America in two independent dispersal events, Cuvieronius spread across the Andean corridor, while Notiomastodon extent along the eastern route. Cuvieronius hyodon is geographically restricted to the Andean Region in Ecuador, Peru, Bolivia, and Chile. Notiomastodon platensis was recorded in Ecuador, Brazil, Uruguay, Paraguay, Chile, and Argentina, especially the Pampean Region.

Paleodiet of Lamini camelids (Mammalia: Artiodactyla) from the Pleistocene of southern Brazil: insights from stable isotope analysis (δ13C, δ18O)

AbstractCamelids (Camelidae) were a diverse and widely distributed group in South America during the Pleistocene. According to the fossil record, three species inhabited southern Brazil in the recent past: Hemiauchenia paradoxa, Lama guanicoe, and Vicugna vicugna. The analysis of carbon and oxygen stable isotope ratios in bioapatite provides insight into the paleobiology of nonliving animals and the environment they used to inhabit. We applied this tool to investigate the diet of camelids from two geological localities in southern Brazil: Touro Passo and Santa Vitória Formations (H. paradoxa, n = 7; L. guanicoe, n = 6; V. vicugna, n = 4). Carbon stable isotopes from enamel, dentin, and bone indicated that H. paradoxa and L. guanicoe had diets comprising mostly C3 grasses, but the latter showed a broader diet due to one individual with a mixed diet, whereas V. vicugna had a mixed C3–C4 diet. These different foraging behaviors may have minimized interspecific competition and favored niche partitioning and the coexistence of related species. Combined oxygen and carbon isotope data showed a consistent diet according to climate, probably due to the greater availability in glacial periods of cool-season grasses, which mainly use the C3 photosynthetic pathway. Given their adaptations to grazing, the climate amelioration, followed by the loss of grasslands, likely had a great impact on camelid populations, leading to their extinction in southern Brazil. These results, therefore, contribute to the understanding of the dynamics of paleocommunities in this region.

Ginkgoites villardeseoanii sp. nov., a ginkgophyte with insect damage from the Upper Cretaceous (Maastrichtian) Lefipán Formation (Chubut, Patagonia, Argentina)

Today, the ginkgophytes are represented by the single species Ginkgo biloba, naturally distributed in China and cultivated worldwide. However, the ginkgophyte lineage shows an extensive fossil record going back to the Paleozoic of both hemispheres. In South America, its record began in the upper Paleozoic and reached the middle Eocene, and it includes both vegetative and reproductive remains. The Cretaceous macrofossil record of this group in South America is restricted to Lower Cretaceous deposits, where it is relatively abundant, whereas there is a gap in its Upper Cretaceous to lower Paleogene record. We present the new species Ginkgoites villardeseoanii collected from Maastrichtian (uppermost Cretaceous) deposits of the Lefipán Formation (Patagonia, Argentina). The studied material consists of three specimens preserved as adpressions of isolated, flabellate, and petiolate (Ginkgo-like) leaves, with few epidermal characters preserved. One of the studied specimens shows evidence of insect damage consistent with hole feeding, constituting the first Cretaceous record of interaction between ginkgophytes and insects in the Southern Hemisphere. We infer that this damage was produced when the leaf was still attached to the plant, as the specimen shows evidence of a physiological reaction of the plant in the form of a border of necrotic tissue around the wound. Ginkgoites leaves are common among different lineages within the Ginkgoales, having been associated to three families (Ginkgoaceae, Karkeniaceae, and Yimaiaceae). Therefore, G. villardeseoanii was assigned to an incertae sedis family.

New Caenis Species (Insecta: Ephemeroptera: Caenidae) from Angola, Okavango and Zambezi River Basins

Nine new species of Caenis from Angola are described herein: Caenis wegeneriana sp. n. (imago), Caenis angolensis sp. n. (imago and larva), Caenis branchiata sp. n. (larva), Caenis filappendicessp.n.(imago),Caenisulesisp.n.(larva),Caeniscubangosp.n.(larva),Caenisarmata sp. n. (imago), Caenis brevispinata sp. n. (imago), and Caenis gallocristata sp. n. (imago). The relationship between the newly described species and other known African species is discussed. The vicariant biogeographic affiliation of Caenis wegeneriana to a related species group in South America, separated by continental drift, is considered. A key to the male imagoes is provided, including Caenis antelucana Malzacher, 1990, Caenis brevipes Kimmins, 1956, Caenis douglasi Malzacher, 1993 and Caenis jinjana Kimmins, 1956, which have previously been recorded in the Cunene River, along the shared border with Namibia.

An early Miocene manatee from Colombia and the initial Sirenian invasion of freshwater ecosystems

Potamosiren magdalenensis Reinhart, is an extinct species of manatee (Sirenia, Trichechidae, Trichechinae), which has only been recorded for the middle Miocene Honda Group, in the La Venta area (Huila Department, Colombia). A new specimen referable to Potamosiren cf. P. magdalenensis is reported herein, collected from the early Miocene Barzalosa Formation. This unit crops out in the Pubenza locality, at the Tocaima municipality of the Cundinamarca Department, Colombia. The material described here represents the first evidence of a mammal from the Barzalosa Formation, the earliest record of Potamosiren so far reported and one of the only two trichechid records for the early Miocene of South America. The new specimen adds to a small but growing record of extinct trichechids, increasing the fossil record of this group in South America and allowing us to further explore their evolutionary history. The early Miocene appearance of trichechines coincides geographically and temporally with the onset of the Pebas Mega-Wetland System, which likely provided favourable conditions for the invasion of freshwater ecosystems of this group of fully aquatic mammals. Finally, the depositional environments represented by the Barzalosa Fm and a review of the fossil record of trichechines further support the notion that manatees have had a close association with freshwater systems since early in their evolutionary history, and that reinvasion of marine ecosystems did not occur until much later.

Amiseginae and Cleptinae from northeastern Brazil, with the description of four new species (Hymenoptera, Chrysididae)

The diversity of two subfamilies of cuckoo wasps in northeastern Brazil is reviewed. Four new species are described and illustrated:Amisega boyiLucena,sp. nov.,A. sertanejaLucena,sp. nov., andDuckeia duduiLucena,sp. nov.(Amiseginae), andCleptidea nordestinaLucena,sp. nov.(Cleptinae). These new species ofAmisegaandDuckeiarepresent the first records of both genera in the core zone of the Caatinga dry region, and they seem to be endemic to this portion of the region. The other twoAmisegaspecies previously recorded in northeastern Brazil are restricted to ecotone habitats between Caatinga and Atlantic forest.Cleptidea nordestinaLucena,sp. nov.(Cleptinae) is the most septentrional record for thefasciataspecies group in South America. With the present contribution, the total recorded diversity of Amiseginae and Cleptinae in northeastern Brazil is represented by the following species:A. boyiLucena,sp. nov.,A. flavipesKimsey, 1987,A. sertanejaLucena,sp. nov.,A. similisKimsey, 1987, andD. duduiLucena,sp. nov.(Amiseginae), andC. nordestinaLucena,sp. nov.(Cleptinae).

Entomophagy and the preservation of human food security

Food security is a concern in many developing and less developed nations, owing to the rise in human population, as well as the decline in agricultural production and availability of food resources. Edible insects are a naturally occurring, renewable source of food that provides carbohydrates, proteins, lipids, minerals, and vitamins in addition to other nutrients. The practice of eating insects is widespread among ethnic groups in South America, Mexico, Africa, and Asia where indigenous insects are readily accessible and may be eaten in a variety of ways (raw/processed), as well as utilized as an ingredient or supplement in contemporary cuisine. Entomophagy, as a result, provides a chance to close the protein gap in human diets, notwithstanding a few limitations that have been addressed. In terms of food security, greater attention should be paid to evaluating and revalidating entomophagy in the context of contemporary living. Further study would be required to fully utilize insect biodiversity and ethno-entomophagy, to prevent overexploitation of these insects, and to start conservation efforts aimed at protecting insects.

The genetic characterization of fall armyworm populations in Ecuador and its implications to migration and pest management in the northern regions of South America.

The fall armyworm (Spodoptera frugiperda) is a moth pest native to the Western Hemisphere that has recently become a global problem, invading Africa, Asia, and Australia. The species has a broad host range, long-distance migration capability, and a propensity for the generation of pesticide resistance traits that make it a formidable invasive threat and a difficult pest to control. While fall armyworm migration has been extensively studied in North America, where annual migrations of thousands of kilometers are the norm, migration patterns in South America are less understood. As a first step to address this issue we have been genetically characterizing fall armyworm populations in Ecuador, a country in the northern portion of South America that has not been extensively surveyed for this pest. These studies confirm and extend past findings indicating similarities in the fall armyworm populations from Ecuador, Trinidad-Tobago, Peru, and Bolivia that suggest substantial migratory interactions. Specifically, we found that populations throughout Ecuador are genetically homogeneous, indicating that the Andes mountain range is not a long-term barrier to fall armyworm migration. Quantification of genetic variation in an intron sequence describe patterns of similarity between fall armyworm from different locations in South America with implications for how migration might be occurring. In addition, we unexpectedly found these observations only apply to one subset of fall armyworm (the C-strain), as the other group (R-strain) was not present in Ecuador. The results suggest differences in migration behavior between fall armyworm groups in South America that appear to be related to differences in host plant preferences.

The presence of Guaraní groups in the current Uruguayan territory

The Amazon has traditionally been seen as the scenery for different original human experiences. In recent years, research has allowed us to improve our knowledge of the territorial and cultural dynamics of Amazonian groups in South America. In this context, the spatial analysis of ceramic traditions allows us to know and recognize the dispersion of groups of Arawak and Guaraní matrix towards places as distant as the La Plata river. These episodes of human migration seem to have begun about 2000 years ago BP, and they allow us to recognize precise cultural matrices, diverse archaeological contexts, and create reliable chronologies.This work presents information on the Guaraní cultural tradition, based on the survey of presence of ceramic material attributed to this group. The diverse contexts in which this material has been recorded are analyzed, as well as the cultural dynamics in which it could be involved. The relevance that the La Plata river has within a wide sphere of cultural interaction that links the Southern Cone of South America with Amazonia is also discussed.

The Great American Biotic Interchange revisited: a new perspective from the stable isotope record of Argentine Pampas fossil mammals

This study aims at assessing resource and habitat use, niche occupation and trophic interactions from a stable isotope perspective on fossil mammals from the Argentine Pampas during the Great American Biotic Interchange (GABI). We present stable isotope data of more than 400 samples belonging to 10 mammalian orders and spanning a temporal range from ~9.5 Ma to ~12 ky. Rodents, notoungulates and pilosians record an increase in the consumption of C4 plants, whereas litopterns and cingulates show δ13C values that remain mostly within a C3-dominated diet. Our stable isotope data indicates that the expansion of C4 vegetation opened up new niche opportunities, probably alleviating resource competition among endemic taxa. Gomphothere, equid and camelid δ13C records show a broad variability pointing to consumption of C3 and mixed C3-C4 vegetation. This flexible dietary behavior may have facilitated the successful settlement of immigrant groups in South America. In the case of carnivorous taxa, Late Miocene pre-GABI endemic sparassodonts consumed prey from C3 environments, whereas immigrant carnivorans preferred prey from mixed C3-C4 areas. Our research contributes to the study of the GABI from a different perspective as stable isotope records permit to characterize, from a (semi)quantitative standpoint, ecological traits within extinct fauna.

A Culturally Adapted Cognitive Behavioral Internet-Delivered Intervention for Depressive Symptoms: Randomized Controlled Trial.

BackgroundInternet-delivered treatments for depressive symptoms have proved to be successful in high-income Western countries. There may be potential for implementing such treatments in low- and middle-income countries such as Colombia, where access to mental health services is limited.ObjectiveThe objective of this study was to assess the efficacy of a culturally adapted cognitive behavioral internet-delivered treatment for college students with depressive symptoms in Colombia.MethodsThis was a randomized controlled trial with a 3-month follow-up. The program comprised seven modules. A total of 214 Colombian college students were recruited. They were assessed and randomly assigned to either the treatment group (n=107) or a waiting list (WL) control group (n=107). Participants received weekly support from a trained supporter. The primary outcome was symptoms of depression, as measured by the Patient Health Questionnaire - 9, and the secondary outcomes were anxiety symptoms assessed by the Generalized Anxiety Disorder questionnaire - 7. Other measures, including satisfaction with treatment, were evaluated after 7 weeks.ResultsResearch attrition and treatment dropouts were high in this study. On average, 7.6 sessions were completed per user. The mean time spent on the program was 3 hours and 18 min. The linear mixed model (LMM) showed significant effects after treatment (t 197.54=−5.189; P<.001) for the treatment group, and these effects were maintained at the 3-month follow-up (t 39.62=4.668; P<.001). Within-group results for the treatment group yielded a large effect size post treatment (d=1.44; P<.001), and this was maintained at the 3-month follow-up (d=1.81; P<.001). In addition, the LMM showed significant differences between the groups (t 197.54=−5.189; P<.001). The results showed a large effect size between the groups (d=0.91; P<.001). In the treatment group, 76.0% (16/107) achieved a reliable change, compared with 32.0% (17/107) in the WL control group. The difference between groups was statistically significant (X22=10.5; P=.001).ConclusionsThis study was the first contribution to investigating the potential impact of a culturally adapted internet-delivered treatment on depressive symptoms for college students as compared with a WL control group in South America. Future research should focus on identifying variables associated both with premature dropout and treatment withdrawal at follow-up.Trial RegistrationClinicalTrials.gov NCT03062215; https://clinicaltrials.gov/ct2/show/NCT03062215

The Karyotypic Diversification of Calophysines and the Exallodontus-Propimelodus Clade (Pimelodidae, Siluriformes): A Cytotaxonomic and Evolutionary Approach in Pimelodidae Based on Ancestral State Reconstruction.

Pimelodidae family is one of the most diverse and widely distributed fish groups in South America. Phylogenetic analysis in the family have recently indicated the existence of two main clades: "sorubiminae" and the OCP clade, including Pimelodus ornatus, "calophysines" and "pimelodines." The aim of this study was to investigate the karyotype of three Amazonian Pimelodidae species: Calophysus macropterus, Propimelodus eigenmanni, and Exallodontus aguanai associating them to the literature, seeking to reconstruct probable ancestral characters. C. macropterus has 2n = 50, 20m+20sm+10a (fundamental number [FN] = 90), simple interstitial nucleolar organizing regions (NORs), and four 5S rDNA sites terminals, two in synteny with the 18S rDNA. P. eigenmanni has 2n = 56, 28m+20sm+2st+6a (FN = 106), simple NORs, and two 5S rDNA sites terminals. E. aguanai has 2n = 56, 36m+12sm+2st+6a (FN = 106) and 18S and 5S rDNA sites interstitial syntenic in the chromosome 1. All species exhibited a higher amount of heterochromatin, differing from the pattern of the family, and strong marking associated with NORs. The integration between molecular phylogenetic data and karyotype data indicated a high probability that 2n = 56 and simple terminals NORs in the short arm are ancestral characters in Pimelodidae, evidenced in "sorubiminae." In the OCP clade derived traits were observed resulting from chromosomal changes that played a critical role in the karyotype evolution of the group.

The maternal inheritance of the Ashaninka native group from Peru

The Amazonia rainforest, in South America, harbours native populations with high ethnic diversity. The evaluation of the genetic composition of these populations represents a challenge, and only few studies are available describing its native groups. In this work, the maternal inheritance of 170 Ashaninka individuals living in the Amazonia region of Pasco department, Peru, was evaluated by mtDNA control region sequencing. As previously observed for other native groups from Amazonia, low haplotype diversity was obtained, and only Native American haplogroups were found. Strong founder effects were observed, especially for sub haplogroups A2aa, B2b+152, C1b and D1. During the European colonial period, the Ashaninka population seems to have remained relatively isolated, which can be explained by its remote location in the tropical forest. A comparison with other native South American populations from different linguistic families showed a lack of geographic or linguistic affiliations, highlighting the importance of having specific mtDNA database for the native groups in South America.

‘Rauisuchian’ material from the lower Elliot Formation of South Africa and Lesotho: Implications for Late Triassic biogeography and biostratigraphy

‘Rauisuchians’ are non-crocodylomorph pseudosuchian archosaurs that played important roles in terrestrial Triassic ecosystems. Because they are generally considered to have gone extinct in the end-Triassic mass extinction, they are potentially useful for relative dating of terrestrial strata. Despite the abundance of fossils of this group in South America, East Africa and Laurasia, there is currently no published definitive rauisuchian fossil record from southern Africa. However, several fragmentary archosaurian remains representing potential members of this grade have been recovered from the latest Triassic lower Elliot Formation of southern Africa. Here, we critically review this material and show that it represents a modest diversity of rauisuchians. These records are the southernmost palaeolatitudes that these animals are known to have occurred and the first definitive remains from southern Africa.