Modern Populations Research Articles

Changing patterns of genetic differentiation in the slender wild oat, Avena barbata

The slender wild oat (Avena barbata) was widely studied in California using allozymes in the 1970s and interpreted as a case of ecotypic adaptation to contrasting moisture environments. However, common garden studies suggested that the moist-associated ("mesic") ecotype had high fitness in both moist and dry habitats, thus predicting an adaptive spread into areas occupied by the dry associated ("xeric") ecotype. To test this prediction, we revisited 100 populations of A. barbata that were screened genetically 40 y ago. As expected, mesic allozyme and morphological markers are much more common than in the 1970s. The less-fit xeric ecotype, while still widespread, has declined markedly in range and frequency. Genotyping by sequencing of modern populations reveals striking genetic uniformity within each of the two ecotypes. In recombinants between the two ecotypes, the mesic allele at a major fitness quantitative trait locus (QTL) shows a high frequency but so do many other genomic regions not identified as fitness QTL. Additional introduced genotypes are diverse and more widespread than in the past, and our results show that these have spread into the former range of the xeric ecotype to an even greater extent than the mesic ecotype has. While these results confirm the prediction of contemporary evolution from common gardens, they also suggest that much of the change has been driven by additional waves of introduced genotypes.

Ancient DNA from Tubo Kingdom-related tombs in northeastern Tibetan Plateau revealed their genetic affinity to both Tibeto-Burman and Altaic populations.

The rise of the Tubo Kingdom is considered asthe key period for the formation of modern groups on the Tibetan Plateau. The ethnic origin of the residents of the Tubo Kingdom is quite complex, and their genetic structure remains unclear. The tombs of the Tubo Kingdom period in Dulan County, Qinghai Province, dating back to the seventh century, are considered to be the remains left by Tubo conquerors or the Tuyuhun people dominated by the Tubo Kingdom. The human remains of these tombs are ideal materials for studying the population dynamics in the Tubo Kingdom. In this paper, we analyzed the genome-wide data of eight remains from these tombs by shotgun sequencing and multiplex PCR panels and compared the results with data of available ancient and modern populations across East Asia. Genetic continuity between ancient Dulan people with ancient Xianbei tribes in Northeast Asia, ancient settlers on the Tibetan Plateau, and modern Tibeto-Burman populations was found. Surprisingly, one out of eight individuals showed typical genetic features of populations from Central Asia. In summary, the genetic diversity of ancient Dulan people and their affiliations with other populations provide an example of the complex origin of the residents in the Tubo Kingdom and their long-distance connection with populations in a vast geographic region across ancient Asia.

New Data on Nephron Microanatomy and Ultrastructure of Senegal Bichir (Polypterus senegalus).

Simple SummaryTransitional forms of animals between Pisces and Amphibia are interesting to study, as they are the first to begin the development of a new environment - terrestrial. Such a transitional form are amphibious fish. The study of the structure of the nephron, the main structure that performs an osmoregulatory function, makes it possible to build evolutionary series that describe the processes of transition from the aquatic environment to the terrestrial one. Bichirs is a monophyletic group that arose in the Devonian and formed a species complex only in the Neogene. They share features with lungfish and amphibians, which formed convergently in the early stages of evolution. Therefore Bichirs are of great interest as a transitional form of animals. This study presents new data on the nephron age of Polypterus senegalus. Two groups of features are described. The first group consists of ancestral traits that have been preserved in the modern population of P. senegalus and are associated with habitat conditions in the aquatic environment. The second group is a complex of characters associated with the adaptation of P. senegalus to air breathing and periodic ground migrations.This study presents new data on the microanatomy and ultrastructure of Polypterus senegalus nephrons. It was shown that the diameter and ultrastructure of renal corpuscles, a well-developed neck segment, and ultrastructure of two types of epithelial cells of the proximal tubule are ancestral signs of the modern population of P. senegalus associated with habitat conditions in the aquatic environment. The outer diameter of the tubules, the height of the epitheliocytes, the presence of two types of epithelial cells of the intermediate and distal tubules of the corresponding ultrastructure, and a large area of nephrogenic tissue are progressive features of the modern population of P. senegalus, associated with adaptation to air respiration and periodic terrestrial migrations, which were formed at the early stages of evolution of P. senegalus convergently with lungfish and amphibians.

Genome-wide association study of leprosy in Malawi and Mali.

Leprosy is a chronic infection of the skin and peripheral nerves caused by Mycobacterium leprae. Despite recent improvements in disease control, leprosy remains an important cause of infectious disability globally. Large-scale genetic association studies in Chinese, Vietnamese and Indian populations have identified over 30 susceptibility loci for leprosy. There is a significant burden of leprosy in Africa, however it is uncertain whether the findings of published genetic association studies are generalizable to African populations. To address this, we conducted a genome-wide association study (GWAS) of leprosy in Malawian (327 cases, 436 controls) and Malian (247 cases, 368 controls) individuals. In that analysis, we replicated four risk loci previously reported in China, Vietnam and India; MHC Class I and II, LACC1 and SLC29A3. We further identified a novel leprosy susceptibility locus at 10q24 (rs2015583; combined p = 8.81 × 10-9; OR = 0.51 [95% CI 0.40 - 0.64]). Using publicly-available data we characterise regulatory activity at this locus, identifying ACTR1A as a candidate mediator of leprosy risk. This locus shows evidence of recent positive selection and demonstrates pleiotropy with established risk loci for inflammatory bowel disease and childhood-onset asthma. A shared genetic architecture for leprosy and inflammatory bowel disease has been previously described. We expand on this, strengthening the hypothesis that selection pressure driven by leprosy has shaped the evolution of autoimmune and atopic disease in modern populations. More broadly, our data highlights the importance of defining the genetic architecture of disease across genetically diverse populations, and that disease insights derived from GWAS in one population may not translate to all affected populations.

Основатель белорусской школы антропологии Инесса Ивановна Саливон

The article presents the stages of the creative path and the results of many years of work of the outstanding scientist Laureate of the State Prize of the Republic of Belarus Inessa Ivanovna Salivon, who is the founder of the Belarusian school of Anthropology. Her research has given development to several scientific directions in the science of man, such as gender, age, territorial and ecological variability of the physical type of the adult population; the formation of physique in the process of growth and maturation of the child's body; constitutional features of morphogenesis. Since 1965, she began to develop the direction of historical anthropology, devoting her work to the formation and research of osteological collections on the population that lived on the territory of our republic during the II millennium of the new era. The osteological material obtained as a result of the excavations served as a link between the ancient and the now living population in the study of the formation of regional anthropological features of the indigenous population. The aim of this work was the desire to recreate a holistic picture of the historical process of the formation of the physical type of the population, starting from the settlement of the territory by the Slavs up to the present, as well as to identify changes in the physical type of the modern population throughout the life cycle, that is, in the process of ontogenesis. A significant part of Inessa Ivanovna's scientific activity was devoted to the study of the patterns of formation of physical development of children. She conducted a unique longitudinal (from 1982 to 1991), as well as a number of screening studies of morphological parameters in children and adolescents of both sexes. This is a fundamental work, where a comprehensive program was used, which included numerous morphological signs characterizing physical development and features of somatic status, including the development of subcutaneous fat, body proportions, kefalometry indicators and others. Inessa Ivanovna is the author of the development of a new method in anthropology – quantitative assessment of body type.

Исследования Нубийской археолого-антропологической экспедиции НИИ и Музея антропологии МГУ в Центральном Атбае (2017–2022)

Materials and methods. This article is a collective research conducted by the members of the Nubian archaeological and anthropological expedition of the Research Institute and Museum of Anthropology of the Lomonosov Moscow State University. The article outlines the main results of the expedition's work over four field seasons at the Deraheib site, located at the headstream of Wadi al-Allaqi, in the northern part of the Nubian desert (Central Atbai) in the Republic of Sudan. From 2017 to 2022 The Nubian expedition excavated the Northern Fortress, Building 3 (Mosque) at the settlement of Deraheib, the Southern Necropolis; carried out an reconnaissance mission to the Onib ring structure. Results and discussion. Based on the study of the obtained archaeological materials (primarily the analysis of ceramics and textiles), as well as data from written sources, it was established that the medieval part of history of the monument covers the period between the 9th and 12th centuries. The archaeological site of Deraheib can be associated with the city of Al-Allaqi, mentioned in Arabic sources as a gold mining center in the Nubian desert, a trading city that was located on one of the caravan routes connecting the Red Sea port of Aidhab and the city of Aswan. The materials of the excavations of the Northern Fortress made it possible to advance a hypothesis that the building, erected in the 9th century, functioned more like a fortified castle of the local ruler rather than a fortress. The study of Building 3 allows us to say with confidence that it was a Friday mosque, founded at the beginning of the 10th century. Ongoing excavations in the Southern Necropolis have revealed Muslim burials (25 out of 31 investigated burials) and burials that are associated with the population that lived on the territory of Atbai in the Late Antique — Early Medieval period, known from classical sources as Blemmyes. A group of anthropologists obtained important data on the sex and age of the population of Deraheib, traces of daily activities and pathologies reflected in the skeleton. An important direction in the research of the MSU complex expedition is the study of the modern population of Central Atbai, primarily the Bisharin tribe of the Beja tribal union. The article outlines the main directions of these studies and preliminary results.

В поисках аланского следа: генетическая история Северного Кавказа по полногеномным данным об аутосомном генофонде

Introduction. The question of whether the Alans left a genetic heritage in the modern population of the North Caucasus, and if they did, which populations carry it in their gene pool, is not only a problem of basic science, but also an acute issue of public discussion. Population genetics can test the hypothesis of preserving the contribution of the thousand-year history of the Alanian tribes to the gene pools of the modern peoples of the Caucasus. Materials and methods. The genomes of 207 individuals (on a panel of 4.5 million markers) were studied: Abkhazians, Adyghes, Balkarians, Georgians, Dargins, Ingush, Kabardians, Kuban Cossacks, Karachays, Nogais (Astrakhan, Kuban, Stavropol), Laks, Southern Russians, Tabasarans, Farsi-speaking populations of Dagestan, Circassians, Chechens, Yaghnobis. The contribution of ancestral components to each of 207 genomes was modeled using the ADMIXTURE method. 140 independent ADMIXTURE models were created, the optimal model with K=11 ancestral components is analyzed and mapped. Results and discussion. A single ancestral component was not found in the gene pools of the peoples in the area of the "metropolis" of the Alans: of the eleven ancestral components, the greatest contribution to the genomes of the alleged "heirs" of the Alans was made by four, which are connected like a puzzle on the periphery of the areas. "Ossetian" and "Nakh" make the greatest contribution to the genomes of Ossetians, Ingush and Chechens, with a significant contribution to the genomes of other peoples of the North Caucasus. The gene pool of the Balkars appears to be complex – with the largest contribution of the "Abkhaz-Adyghe" and with a small contribution of the "Ossetian" and "Nakh" ancestral components. The Karachay gene pool is dominated by its own "Karachai-Nogai" component. An analysis of the structure of the Ossetian gene pool showed that the contribution of the "Ossetian" ancestral component is higher in the southern societies of Ossetians, and some Ossetian societies could have retained the Alan trace to a greater extent. Conclusion. The hypothesis of the presence of a common Alanian heritage in the gene pools of modern peoples living in the area of the Alanian “metropolis” has not been confirmed. If we assume that both ancestral components – "Ossetian" and "Nakh" – reflect the genetic heritage of the Alans, then we will have to admit a set of unlikely events. To solve the problem, it is necessary to analyze ancient DNA from different parts of the Alanian area from different chronological sections. The pharmacogenetic landscape differs from the pattern found throughout the genome. Therefore, a thorough analysis of the pharmacogenetic profile of populations is necessary for the transition to personalized medicine.

Estimating the population variance, standard deviation, and coefficient of variation: Sample size and accuracy

Small sample sizes are often used in human and primate evolutionary research to estimate population parameters such as the mean, variance, and standard deviation, as well as statistical measures such as the coefficient of variation. Determining how well sample estimates represent population parameters is essential for establishing confidence in the inferences made using those samples. We present methods for determining a priori the probability, based on Cochran's theorem, that the sample variance and sample standard deviation are within a specified fraction of the population parameters. We validate these methods using random resampling with replacement of a single variable from a commonly used large craniometric data set comprising modern human population samples from around the world. Results based on Cochran's theorem, which we validate, indicate that large random samples comprising hundreds of observations, rather than tens of observations, are needed to be confident that the sample estimate is a reasonably accurate approximation of the true population variance. Smaller sample sizes on the order of tens of observations, however, are sufficient for estimating the population standard deviation. We extend our method of validation to show that the coefficient of variation mirrors closely the results for the standard deviation.

Microbial communities of stratified aquatic ecosystems of Kandalaksha Bay (White Sea) shed light on the evolutionary history of green and brown morphotypes of Chlorobiota.

Anoxygenic photoautotrophic metabolism of green sulfur bacteria of the family Chlorobiaceae played a significant role in establishing the Earth's biosphere. Two known major ecological forms of these phototrophs differ in their pigment composition and, therefore, in color: the green and brown forms. The latter form often occurs in low-light environments and is specialized to harvest blue light, which can penetrate to the greatest depth in the water column. In the present work, metagenomic sequencing was used to investigate the natural population of brown Chl. phaeovibrioides ZM in a marine stratified Zeleny Mys lagoon in the Kandalaksha Bay (the White Sea) to supplement the previously obtained genomes of brown Chlorobiaceae. The genomes of brown and green Chlorobiaceae were investigated using comparative genome analysis and phylogenetic and reconciliation analysis to reconstruct the evolution of these ecological forms. Our results support the suggestion that the last common ancestor of Chlorobiaceae belonged to the brown form, i.e. it was adapted to the conditions of low illumination. However, despite the vertical inheritance of these characteristics, among modern Chlorobiaceae populations, the genes responsible for synthesizing the pigments of the brown form are subject to active horizontal transfer.

Archaeological and anthropological characteristics of the Аkterek burial ground

In modern physical anthropology, a significant place is given to the study of the morphology of the dental system. Odontological data contain important information in the study of ethnogenetic processes of ancient and modern populations. In this article, for the first time, an odontological study of craniological materials from the Akterek burial ground, Zhambyl district of Almaty region, was carried out. Paleoanthropological materials from the excavations of the 2014, 2017 and 2021 field seasons were presented. As well as the archaeological data of the burials in which these materials were found. Based on a comparative typological analysis of the accompanying inventory, a historical chronology of these materials was carried out, which covers the period from the II century BC – I century AD to the VI-X centuries AD. The research program included 15 odontological, 2 odo-glyphic signs. Evaluation of signs and their analysis were carried out in accordance with the methodology and methodology of A.A. Zubov. The results of the study allow us to draw conclusions about the Caucasian, odontogenetic basis in the anthropological composition of the population of Akterek. The results of the study prove that the anthropological type of this period is very similar to the Saks of the early Iron Age of Central Kazakhstan, especially according to the signs of the western complex. The anthropological type of the Ak Terek series of the Turkic and ancient period belongs to the Western odontological complex, the Mongoloid elements are very poorly reflected. This is evidenced by the 114 signs of the “eastern” complex of enamel congestion and the anterior fossa of the second lower molar. In general, the comparative analysis definitely indicates the similarity of the Actors with the series Kultobe (South Kazakhstan), Old Terbez, Dalverzintepe (Uzbekistan). Key words: archaeology, burial mounds, monuments, anthropology, odontology, paleoanthropology, craniology, erasure, complex, typological.

Некоторые результаты биоархеологических и этноэкологических исследований в Таджикистане

The article describes several topics of joint Russian-Tajik research conducted since 2013 in the Khatlon velayat of the Republic of Tajikistan within the framework of the Memorandum of Cooperation between the N. N. Miklukho-Maklay Institute of Ethnology and Anthropology of Russian Academy of Sciences and the A. Donish Institute of History, Archaeology and Ethnography of the National Academy of Sciences of Tajikistan. Th e text includes several interconnected blocks: archaeological excavations, ethnoecological study of the subsistence systems of the modern and medieval populations, and collection and analysis of human remains. Th e article gives brief information about the archaeological excavations of the Shakhidon burial ground of the 7th–8th centuries (Baljuvan jamoat), anthropological characteristics of the population buried in it and information about the economy of the population of the dekh Shaidon, where the site is located, as well as materials on other regions of the Republic.

From footprint morphometrics to the stature of fossil hominins: A common but uncertain estimate

Hominin footprints are a particular remain in paleoanthropology representing brief moments of life of extinct individuals. Footprints not only provide information on the locomotor behavior of fossil taxa but also on their body characteristics such as their stature. This stature is usually estimated from the length of the footprints based on the well-known foot length to stature ratio. However, footprint length does not result only from the foot length but of a combination of factors. Therefore, it is necessary to investigate the relationships between footprint length and stature of individuals using experimental approaches. Secondly, recent discoveries of fossil footprints have led to the estimation of statures from isolated footprints. However, such estimates may be biased because of the intraindividual morphometric variation of the footprints. Moreover, footprints may also be incomplete making it impossible to measure the length and therefore the estimation of a stature. The search for relationships between stature and other morphometric variables is therefore necessary to have the most accurate picture possible of the individuals who left these tracks. In this context, this article reports the results of an experimental study that aims to determine the relationships between the stature of individuals and different morphometric variables and to quantify the intraindividual variation of each variable. Thus, 21 morphometric variables were measured on a total of 175 experimental footprints left by 20 individuals in an experimental area composed of loose sand. Statistical analyses show that footprint lengths are not only the variables most correlated with stature but also those with the least intraindividual variation. However, estimation of stature from footprints left by fossil hominins is subject to three types of uncertainties: residuals from linear regression, intraindividual variation that can be particularly large in soft substrates, and the application of relationships defined on modern populations to fossil taxa.

Fragilaria radians (Kützing) D.M.Williams et Round, the correct name for F. gracilis (Fragilariaceae, Bacillariophyta): a critical analysis of this species complex in Europe

Fragilaria gracilis is one of the most reported Fragilaria species in Europe, observed in a broad range of water bodies, ranging from (ultra)oligotrophic rivers to even eutrophic lakes. A revision of this important taxon based on the analysis of the morphology of a large number of historic and recent populations was highly needed. In the present study, type material of Fragilaria gracilis and several related taxa such as Synedra radians, Fragilaria pseudolaevissima, S. utermoehlii, F. aquaplus, F. boreomongolica and F. tridentina together with more than 10 modern populations were investigated using LM and SEM observations. The results based on these comparisons show that Fragilaria (Synedra) radians is the name for the taxon formerly known as F. gracilis. Moreover, detailed analysis demonstrated that F. pseudolaevissima and Synedra utermoehlii are conspecific with F. radians and should be considered as heterotypic synonyms. The observations made in this study also resulted in the description of several new species, often with distinct ecologies and distribution areas: Fragilaria huerlimannii Van de Vijver sp. nov., F. acerosa Van de Vijver, C.E.Wetzel, Jarlman et Ector sp. nov., F. neglecta Van de Vijver, C.E.Wetzel, Jarlman et Ector sp. nov., F. heudreana Van de Vijver, C.E.Wetzel et Ector sp. nov., F. eutraphenta Van de Vijver, Kusber et D.M.Williams sp. nov., and F. mertensiana Van de Vijver, C.E.Wetzel et Ector sp. nov. Using an analysis of the associated diatom flora, the ecological preferences of each taxon are briefly discussed.

Prevalence of arterial hypotension with a poor prognosis in populations of the Russian Federation and the United States of America

Aim. To study the prevalence of hypotension (HoTN) with an unfavorable prognosis in populations of the Russian Federation and the United States of America in a thirty-year perspective.Material and methods. We used data from Russian population-based studies performed in 1975-1982 at the now-familiar National Medical Research Center for Therapy and Preventive Medicine, and the study Epidemiology of Cardiovascular Diseases and their Risk Factors in Regions of Russian Federation (ESSE-RF) in 2012-2014. A comparison was made with data from studies of US population of the National Health and Nutrition Examination Survey (NHANES): NHANES II (1976-1980) and Continuous NHANES (2007-2012). Age, sex, systolic and diastolic blood pressure were analyzed. The proportion of persons with HoTN (prevalence) was calculated in men and women of five age groups using the original HoTN criterion. Results. We used the previously developed criterion of HoTN with an unfavorable prognosis: for Russian populations, the mean dynamic pressure is <76 and <72 mm Hg, respectively. The prevalence of HoTN in modern populations was 0,1±0,5% in Russia and 6,0±8,7% in the USA (confidence interval for significance level P=0,95). For 30 years, the prevalence of HoTN in Russia according to this criterion has not changed, while in the USA it has increased both in men (on average 3 times) and in women (2,5 times).Conclusion. The prevalence of unfavorable HoTN in the US adult population is many times higher than in Russia over the entire analyzed period of time, while over 30 years in the US it has increased by 2,5-3 times.

Museum Genomics of an Agricultural Super-Pest, the Colorado Potato Beetle, Leptinotarsa decemlineata (Chrysomelidae), Provides Evidence of Adaptation from Standing Variation.

Despite extensive research on agricultural pests, our knowledge about their evolutionary history is often limited. A mechanistic understanding of the demographic changes and modes of adaptation remains an important goal, as it improves our understanding of organismal responses to environmental change and our ability to sustainably manage pest populations. Emerging genomic datasets now allow for characterization of demographic and adaptive processes, but face limits when they are drawn from contemporary samples, especially in the context of strong demographic change, repeated selection, or adaptation involving modest shifts in allele frequency at many loci. Temporal sampling, however, can improve our ability to reconstruct evolutionary events. Here, we leverage museum samples to examine whether population genomic diversity and structure has changed over time, and to identify genomic regions that appear to be under selection. We focus on the Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say 1824; Coleoptera: Chrysomelidae), which is widely regarded as a super-pest due to its rapid, and repeated, evolution to insecticides. By combining whole genome resequencing data from 78 museum samples with modern sampling, we demonstrate that CPB expanded rapidly in the 19th century, leading to a reduction in diversity and limited genetic structure from the Midwest to Northeast United States. Temporal genome scans provide extensive evidence for selection acting in resistant field populations in Wisconsin and New York, including numerous known insecticide resistance genes. We also validate these results by showing that known selective sweeps in modern populations are identified by our genome scan. Perhaps most importantly, temporal analysis indicates selection on standing genetic variation, as we find evidence for parallel evolution in the two geographical regions. Parallel evolution involves a range of phenotypic traits not previously identified as under selection in CPB, such as reproductive and morphological functional pathways that might be important for adaptation to agricultural habitats.

Endostructural and periosteal growth of the human humerus.

The growth and development of long bones are of considerable interests in the fields of comparative anatomy and palaeoanthropology, as evolutionary changes and adaptations to specific physical activity patterns are expected to be revealed during bone ontogeny. Traditionally, the cross-sectional geometry of long bones has been examined at discrete locations usually placed at set intervals or fixed percentage distances along the midline axis of the bone shaft. More recently, the technique of morphometric mapping has enabled the continuous analysis of shape variation along the shaft. Here we extend this technique to the full sequence of late fetal and postnatal development of the humeral shaft in a modern human population sample, with the aim of establishing the shape changes during growth and their relationship with the development of the arm musculature and activity patterns. A sample of modern human humeri from individuals of age ranging from 24 weeks in utero to 18 years was imaged using microtomography at multiple resolutions and custom Matlab scripts. Standard biomechanical properties, cortical thickness, surface curvature, and pseudo-landmarks were extracted along radial vectors spaced at intervals of 1° at each 0.5% longitudinal increment measured along the shaft axis. Heat maps were also generated for cortical thickness and surface curvature. The results demonstrate that a whole bone approach to analysis of cross-sectional geometry is more desirable where possible, as there is a continuous pattern of variation along the shaft. It is also possible to discriminate very young individuals and adolescents from other groups by relative cortical thickness, and also by periosteal surface curvature.

Genomic insight into the population history and biological adaptations of high-altitude Tibetan highlanders in Nagqu

Tibetan, one of the largest indigenous populations living in the high-altitude region of the Tibetan Plateau (TP), has developed a suite of physiological adaptation strategies to cope with the extreme highland environment in TP. Here, we reported genome-wide SNP data from 48 Kham-speaking Nagqu Tibetans and analyzed it with published data from 1,067 individuals in 167 modern and ancient populations to characterize the detailed Tibetan subgroup history and population substructure. Overall, the patterns of allele sharing and haplotype sharing suggested (1) the relatively genetic homogeny between the studied Nagqu Tibetans and ancient Nepalese as well as present-day core Tibetans from Lhasa, Nagqu, and Shigatse; and (2) the close relationship between our studied Kham-speaking Nagqu Tibetans and Kham-speaking Chamdo Tibetans. The fitted qpAdm models showed that the studied Nagqu Tibetans could be fitted as having the main ancestry from late Neolithic upper Yellow River millet farmers and deeply diverged lineages from Southern East Asians (represented by Upper Paleolithic Guangxi_Longlin and Laos_Hoabinhian), and a non-neglectable western Steppe herder-related ancestry (∼3%). We further scanned the candidate genomic regions of natural selection for our newly generated Nagqu Tibetans and the published core Tibetans via FST, iHS, and XP-EHH tests. The genes overlapping with these regions were associated with essential human biological functions such as immune response, enzyme activity, signal transduction, skin development, and energy metabolism. Together, our results shed light on the admixture and evolutionary history of Nagqu Tibetan populations.

Global patterns of the cranial form of modern human populations described by analysis of a 3D surface homologous model

This study assessed the regional diversity of the human cranial form by using geometric homologous models based on scanned data from 148 ethnic groups worldwide. This method adopted a template-fitting technique for a nonrigid transformation via the iterative closest point algorithm to generate the homologous meshes. Through the application of principal component analysis to 342 sampled homologous models, the largest variation was detected in overall size, and small South Asian crania were clearly verified. The next greatest diversity was found in the length/breadth proportion of the neurocranium, which showed the contrast between the elongated crania of Africans and the globular crania of Northeast Asians. Notably, this component was slightly correlated with the facial profile. Well-known facial features, such as the forward projection of the cheek among Northeast Asians and compaction of the European maxilla, were reconfirmed. These facial variations were highly correlated with the calvarial outline, particularly the degree of frontal and occipital inclines. An allometric pattern was detected in facial proportions in relation to overall cranial size; in larger crania, the facial profiles tend to be longer and narrower, as demonstrated among many American natives and Northeast Asians. Although our study did not include data on environmental variables that are likely to affect cranial morphology, such as climate or dietary conditions, the large datasets of homologous cranial models will be usefully available for seeking various attributions to phenotypic skeletal characteristics.

An improved model for the population dynamics of cattle gastrointestinal nematodes on pasture: parameterisation and field validation for Ostertagia ostertagi and Cooperia oncophora in northern temperate zones

Gastrointestinal nematodes (GIN) are amongst the most important pathogens of grazing ruminants worldwide, resulting in negative impacts on cattle health and production. The dynamics of infection are driven in large part by the influence of climate and weather on free-living stages on pasture, and computer models have been developed to predict infective larval abundance and guide management strategies. Significant uncertainties around key model parameters limits effective application of these models to GIN in cattle, however, and these parameters are difficult to estimate in natural populations of mixed GIN species. In this paper, recent advances in molecular biology, specifically ITS-2 rDNA ‘nemabiome’ metabarcoding, are synthesised with a modern population dynamic model, GLOWORM-FL, to overcome this limitation. Experiments under controlled conditions were used to estimate rainfall constraints on migration of infective L3 larvae out of faeces, and their survival in faeces and soil across a temperature gradient, with nemabiome metabarcoding data permitting species-specific estimates for Ostertagia ostertagi and Cooperia oncophora in mixed natural populations. Results showed that L3 of both species survived well in faeces and soil between 0 and 30 °C, and required at least 5 mm of rainfall daily to migrate out of faeces, with the proportion migrating increasing with the amount of rainfall. These estimates were applied within the model using weather and grazing data and use to predict patterns of larval availability on pasture on three commercial beef farms in western Canada. The model performed well overall in predicting the observed seasonal patterns but some discrepancies were evident which should guide further iterative improvements in model development and field methods. The model was also applied to illustrate its use in exploring differences in predicted seasonal transmission patterns in different regions. Such predictive modelling can help inform evidence-based parasite control strategies which are increasingly needed due climate change and drug resistance. The work presented here also illustrates the added value of combining molecular biology and population dynamics to advance predictive understanding of parasite infections.

Spatio-temporal distribution of ostracod species in saline inland lakes (Mansfeld lake area; Central Germany).

Ostracods are a diverse group of microcrustaceans with a ubiquitous distribution in a wide array of aquatic habitats and are common constituents of lake sediments. Inferences on the temporal-spatial distribution of ostracod species is a prerequisite for reconstructions of palaeoenvironmental conditions. This requires a precise knowledge not only about ecological preferences and specific life histories, but also the understanding how (local) ecological parameters affect ostracod species assemblages (abundance and composition). Generally, these studies are rare and often characterized by an insufficient differentiation of living specimens from the total amount of valves of the modern population leading to uncertainties in species occurrences and diversity data. Modern ostracod populations were sampled from 12 water bodies within a relatively small study area (Mansfeld lake area, Central Germany). Physico-chemical parameters (temperature, oxygen content, conductivity, pH) were measured in situ and the uppermost 2 cm of sediment were collected in different seasons (April, June, September). Relative abundances of ostracods (living and dead), differentiated for adults and juveniles, were used for statistical analyses (Spearman‘s rank correlation, Canonical correspondence analysis, Cluster analyses, Fisher’s α), to investigate relationships between species distribution and environmental factors as well as to identify habitat similarities and ostracod species assemblages. In total, 27 ostracod species (20 living species) were identified. Majority of them are considered as very common (cosmopolitan) freshwater species. Only two species are usually known from brackish water (Cytheromorpha fuscata and Cyprideis torosa). This is the first confirmation of living C. torosa in German inland waters. The relative abundances of ostracods show strong fluctuations during the study period and differences in composition of the ostracod species assemblages between and within the water bodies. There are also strong differences between bio- and taphocoenoses. The measured physico-chemical parameters which are usually considered as most important drivers on ostracod species distribution do not contribute to explain the observed temporal-spatial distribution of the ostracod species. Differences in taphocoenoses show, that taphonomic processes can be very local and the sampling site, as well as the sampling time, is crucial. Biodiversity of ostracods is biased by sampling time, the variability of the ostracod assemblages between sampling month and the relationship between abundance of valves and living ostracods is not straightforward. Therefore, without precise knowledge of the ecological requirements of a species at a local scale, uncertainties may exist for the palaeoecological indication of a species.