Disparate and parallel craniofacial climatic adaptations in native populations of Asia, North America, and South America.

Understanding the impact that climate had in shaping cranial variation is critical for inferring the evolutionary mechanisms that played a role in human diversification. Here, we provide a comprehensive study aiming to analyze the association between climate and cranial variation of high latitude populations living in temperate to cold environments of Asia, North America, and South America. For this, we compiled a large morphometric dataset (N = 2633), which was combined with climatic and genomic data. We tested the influence of climate on the facial skeleton, nasal protrusion, and cranial vault and through multiple statistical tests at two geographical scales: intracontinental and intercontinental. We show that populations living in cold areas share a morphological pattern characterized by an increase in nasal height, facial and orbital heights and widths, a decrease in facial protrusion, and larger, longer, and lower cranial vaults. There are also distinctive features; populations from north Asia present the tallest noses, largest faces, and cranial vaults of the whole sample. Nasal breadth dimensions show small values in Asians, large values in South Americans, and non-significant changes in arctic North America. The morphological pattern in populations living at high latitude may be the result of parallel adaptation, as supported by physiological, morphometric, ecological, and genetic explanations, while the differences in magnitude and phenotypic expression could be due to the diverse population histories, severity of climate, and cultural strategies. Overall, our study shows that climate is a relevant factor shaping modern human morphology and it should be considered when studying modern human evolution and diversification.

The antiquity and ancestral origin of humans in the americas: a five hundred year inquiry from a biological anthropology perspective.

The questions -When did humans arrive in the Americas? Who were they, or from where did they come from? -are enduring and fascinating inquiries that have been approached from different perspectives, thanks to the contributions of archaeology, biological anthropology, and linguistics, among other disciplines. As a result, and after several centuries of studies, this body of research inspired several proposed models on the peopling of the Americas. These models are not only equally unique from each other but also distinct from the current themes in recent literature. However, there is a limited and occasionally inaccurate reference to the knowledge produced in the peripheral countries. This may be attributed to differences in language, academic traditions, as well as the consequences of geopolitics and neocolonialism in science. By reviewing both the old and recent literature, my aim is to present a historical account of how biological evidence has contributed to supporting and discussing some of the broad models that were proposed to explain the peopling of the Americas. Instead of providing an exhaustive account on the models, herein I focus on critically linking evidence and discussions ranging from the early skeletal discoveries at Lagoa Santa in Brazil in the 1830s to the current challenges of integrating a large amount of disparate data and collaborating with indigenous communities in the "omics" era. Far from being fully understood, investigations into the antiquity and the ancestral origin of Native Americans are revealing that these complex questions should be addressed by combining diverse data, articulating information at finer and larger grain scales, and adopting a sensitive and respectful approach by engaging with the views of indigenous communities.

On Roth's "human fossil" from Baradero, Buenos Aires Province, Argentina: morphological and genetic analysis.

The "human fossil" from Baradero, Buenos Aires Province, Argentina, is a collection of skeleton parts first recovered by the paleontologist Santiago Roth and further studied by the anthropologist Rudolf Martin. By the end of the nineteenth century and beginning of the twentieth century it was considered one of the oldest human skeletons from South America's southern cone. Here, we present the results of an interdisciplinary approach to study and contextualize the ancient individual remains. We discuss the context of the finding by first compiling the available evidence associated with the historical information and any previous scientific publications on this individual. Then, we conducted an osteobiographical assessment, by which we evaluated the sex, age, and overall preservation of the skeleton based on morphological features. To obtain a 3D virtual reconstruction of the skull, we performed high resolution CT-scans on selected skull fragments and the mandible. This was followed by the extraction of bone tissue and tooth samples for radiocarbon and genetic analyses, which brought only limited results due to poor preservation and possible contamination. We estimate that the individual from Baradero is a middle-aged adult male. We conclude that the revision of foundational collections with current methodological tools brings new insights and clarifies long held assumptions on the significance of samples that were recovered when archaeology was not yet professionalized.

Craniovascular variation in four late Holocene human samples from southern South America.

Craniovascular traits in the endocranium (traces of middle meningeal vessels and dural venous sinuses, emissary foramina) provide evidence of vascular anatomy in osteological samples. We investigate the craniovascular variation in four South American samples and the effect of artificial cranial modifications (ACM). CT scans of human adult crania from four archeological samples from southern South America (including skulls with ACM) are used for the analyses. The craniovascular features in the four samples are described, skulls with and without ACM are compared, and additionally, South Americans are compared to a previously analyzed sample of Europeans. Of the four South American samples, the Southern Patagonian differs the most, showing the most distinct cranial dimensions, no ACM, and larger diameters of the emissary foramina. Unlike previous studies, we did not find any major differences in craniovascular features between modified and non-modified skulls, except that the skulls with ACM present somewhat smaller foramina. South Americans significantly differed from Europeans, especially in the anteroposterior dominance of the middle meningeal artery, in the pattern of sinus confluence, in the occurrence of enlarged occipito-marginal sinuses, and in foramina frequencies and diameters. Craniovascular morphology is not affected by the cranial size, even in skulls with ACM, indicating a minor or null influence of structural topological factors. Concerning the samples from distinct geographic and climatic environments, it must be evaluated whether the craniovascular morphogenesis might be partially influenced by specific functions possibly associated with thermoregulation, intracranial pressure, and the maintenance of intracranial homeostasis.

Morphometric affinities and direct radiocarbon dating of the Toca dos Coqueiros' skull (Serra da Capivara, Brazil).

The biological variation of the earliest skeletons of South America has been intensely debated for the last two centuries. One of the major research constraints has been the limited number of available samples dating to the early Holocene. We here present the first direct radiocarbon-date for the early Holocene human skeleton from Toca dos Coqueiros (Serra da Capivara, Brazil), also known as "Zuzu" (8640 ± 30 BP; 9526-9681 cal years BP). We performed craniometric analyses using exclusively samples from Brazil, to revisit the sex of the skeleton, and to discuss the evolutionary processes involved in the occupation of the continent. The sex of the individual was estimated as a female when compared to late and early Holocene individuals, but as a male when compared only to the early Holocene series. We also found that Zuzu presents the strongest differences with the late Holocene Guajajara individuals, located nearby, and the strongest similarities with the early Holocene series from Lagoa Santa, attesting for solid biological affinities among early Holocene individuals from Brazil, as well as a moderate level of morphological variation among them. This suggests that the early individuals were part of the same heterogeneous lineage, possibly a different one from which late Holocene populations diverged.

Diversity regained: Precautionary approaches to COVID-19 as a phenomenon of the total environment.

As COVID-19 emerged as a phenomenon of the total environment, and despite the intertwined and complex relationships that make humanity an organic part of the Bio- and Geospheres, the majority of our responses to it have been corrective in character, with few or no consideration for unintended consequences which bring about further vulnerability to unanticipated global events. Tackling COVID-19 entails a systemic and precautionary approach to human-nature relations, which we frame as regaining diversity in the Geo-, Bio-, and Anthropospheres. Its implementation requires nothing short of an overhaul in the way we interact with and build knowledge from natural and social environments. Hence, we discuss the urgency of shifting from current to precautionary approaches to COVID-19 and look, through the lens of diversity, at the anticipated benefits in four systems crucially affecting and affected by the pandemic: health, land, knowledge and innovation. Our reflections offer a glimpse of the sort of changes needed, from pursuing planetary health and creating more harmonious forms of land use to providing a multi-level platform for other ways of knowing/understanding and turning innovation into a source of global public goods. These exemplary initiatives introduce and solidify systemic thinking in policymaking and move priorities from reaction-based strategies to precautionary frameworks.

Diversity lost: COVID-19 as a phenomenon of the total environment.

If we want to learn how to deal with the COVID-19 pandemic, we have to embrace the complexity of this global phenomenon and capture interdependencies across scales and contexts. Yet, we still lack systematic approaches that we can use to deal holistically with the pandemic and its effects. In this Discussion, we first introduce a framework that highlights the systemic nature of the COVID-19 pandemic from the perspective of the total environment as a self-regulating and evolving system comprising of three spheres, the Geosphere, the Biosphere, and the Anthroposphere. Then, we use this framework to explore and organize information from the rapidly growing number of scientific papers, preprints, preliminary scientific reports, and journalistic pieces that give insights into the pandemic crisis. With this work, we point out that the pandemic should be understood as the result of preconditions that led to depletion of human, biological, and geochemical diversity as well as of feedback that differentially impacted the three spheres. We contend that protecting and promoting diversity, is necessary to contribute to more effective decision-making processes and policy interventions to face the current and future pandemics.

Comparing Methods to Assess Intraobserver Measurement Error of 3D Craniofacial Landmarks Using Geometric Morphometrics Through a Digitizer Arm.

Intraobserver error (INTRA-OE) is the difference between repeated measurements of the same variable made by the same observer. The objective of this work was to evaluate INTRA-OE from 3D landmarks registered with a Microscribe, in different datasets: (A) the 3D coordinates, (B) linear measurements calculated from A, and (C) the six-first principal component axes. INTRA-OE was analyzed by digitizing 42 landmarks from 23 skulls in three events two weeks apart from each other. Systematic error was tested through repeated measures ANOVA (ANOVA-RM), while random error through intraclass correlation coefficient. Results showed that the largest differences between the three observations were found in the first dataset. Some anatomical points like nasion, ectoconchion, temporosphenoparietal, asterion, and temporomandibular presented the highest INTRA-OE. In the second dataset, local distances had higher INTRA-OE than global distances while the third dataset showed the lowest INTRA-OE.

Spatial variation of dental caries in late holocene samples of Southern South America: A geostatistical study.

OBJECTIVE: The spatial variation of dental caries in late Holocene southern South American populations will be analyzed using geostatistical methods. The existence of a continuous geographical pattern of dental caries variation will be tested. METHODS: The author recorded dental caries in 400 individuals, collated this information with published caries data from 666 additional individuals, and calculated a Caries Index. The caries spatial distribution was evaluated by means of 2D maps and scatterplots. Geostatistical analyses were performed by calculating Moran's I, correlograms and a Procrustes analysis. RESULTS: There is a relatively strong latitudinal continuous gradient of dental caries variation, especially in the extremes of the distribution. Moreover, the association between dental caries and geography was relatively high (m12 = 0.6). Although northern and southern samples had the highest and lowest frequencies of dental caries, respectively, the central ones had the largest variation and had lower rates of caries than expected. CONCLUSION: The large variation in frequencies of dental caries in populations located in the center of the distribution could be explained by their subsistence strategies, characterized either by the consumption of wild cariogenic plants or cultigens (obtained locally or by exchange), a reliance on fishing, or the incorporation of plants rich in starch rather than carbohydrates. It is suggested that dental caries must be considered a multifactorial disease which results from the interaction of cultural practices and environmental factors. This can change how we understand subsistence strategies as well as how we interpret dental caries rates. Am. J. Hum. Biol., 2016. © 2016 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:825-836, 2016. © 2016Wiley Periodicals, Inc.