Population Affinities Research Articles

Forensic sex estimation using the vertebrae: an evaluation on two European populations.

Sex estimation is one of the primary steps for constructing the biological profile of skeletal remains leading to their identification in the forensic context. While the pelvis is the most sex diagnostic bone, the cranium and other post-cranial elements have been extensively studied. Earlier research has also focused on the vertebral column with varying results regarding its sex classification accuracy as well as the underlying population specificity. The present study focuses on three easily identifiable vertebrae, namely T1, T12, and L1, and utilizes two modern European populations, a Greek and a Danish, to evaluate their forensic utility in sex identification. To this end, 865 vertebrae from 339 individuals have been analyzed for sexual dimorphism by further evaluating the effects of age-at-death and population affinity on its expression. Our results show that T1 is the best sex diagnostic vertebra for both populations reaching cross-validated accuracy of almost 90%, while age-at-death has limited effect on its sexual dimorphism. On the contrary, T12 and L1 produced varying results ranging from 75 to 83% accuracy with the Greek population exhibiting distinctively more pronounced sexual dimorphism. Additionally, age-at-death had significant effect on sexual dimorphism of T12 and L1 and especially in the Greek female and Danish male groups. Our results on inter-population comparison suggest that vertebral sex discriminant functions, and especially those utilizing multiple measurements, are highly population specific and optimally suitable only for their targeted population. An open-source software tool to facilitate classifying new cases based on our results is made freely available to forensic researchers.

A paleogenetic perspective of the Sabana de Bogotá (Northern South America) population history over the Holocene (9000–550 cal BP)

On the basis of distinct lines of evidence, detailed reconstructions of the Holocene population history of the Sabana de Bogotá (SB) region, Northern South America, have been performed. Currently, there exist two competing models that support temporal continuity or, alternatively, divergence. Despite recent bioarchaeological and isotopic research that lends support to the population discontinuity model, several discrepancies remain, calling for other kinds of evidences to be explored for a more detailed picture of Holocene biocultural evolution. In this study, 15 new complete mitochondrial genomes obtained from 30 individuals recovered from several archaeological sites spanning from the late Pleistocene (11,950–11,262 cal BP) until the initial late Holocene (2941–2752 cal BP) along with published data (n = 20) from the region dating ~9000–540 cal BP were used to investigate diachronic genetic change. Genetic diversity and distance indices were calculated, and demographic models tested in an approximate Bayesian computation (ABC) framework to evaluate whether patterns of genetic affinities of the SB prehispanic populations support genetic continuity or discontinuity. The results show that mitochondrial genomes of the complete dataset fall within the Native American haplogroups A2, B2, C1b, D1 and D4h3a. Haplotype and nucleotide diversity declined over time with further evidence of genetic drift and remarkable reduction of genetic diversity during the final late Holocene. Inter-population distances and the exact test of population differentiation, as well as demographic simulations show no population differentiation and population continuity over time. Consequently, based on the analyzed data, we cannot reject the genetic continuity in the SB region as a plausible population history scenario. However, the restriction of the analyses to the Hyper Variable Region 1 of the mitochondrial genome, and the very low sample size both constitute significant limitations to infer evolutionary history.

Quantitative modeling of the effect of antigen dosage on B-cell affinity distributions in maturating germinal centers.

Affinity maturation is a complex dynamical process allowing the immune system to generate antibodies capable of recognizing antigens. We introduce a model for the evolution of the distribution of affinities across the antibody population in germinal centers. The model is amenable to detailed mathematical analysis and gives insight on the mechanisms through which antigen availability controls the rate of maturation and the expansion of the antibody population. It is also capable, upon maximum-likelihood inference of the parameters, to reproduce accurately the distributions of affinities of IgG-secreting cells we measure in mice immunized against Tetanus Toxoid under largely varying conditions (antigen dosage, delay between injections). Both model and experiments show that the average population affinity depends non-monotonically on the antigen dosage. We show that combining quantitative modeling and statistical inference is a concrete way to investigate biological processes underlying affinity maturation (such as selection permissiveness), hardly accessible through measurements.

Testing the utility of dental morphological trait combinations for inferring human neutral genetic variation

Researchers commonly rely on human dental morphological features in order to reconstruct genetic affinities among past individuals and populations, particularly since teeth are often the best preserved part of a human skeleton. Tooth form is considered to be highly heritable and selectively neutral and, therefore, to be an excellent proxy for DNA when none is available. However, until today, it remains poorly understood whether certain dental traits or trait combinations preserve neutral genomic signatures to a greater degree than others. Here, we address this long-standing research gap by systematically testing the utility of 27 common dental traits and >134 million possible trait combinations in reflecting neutral genomic variation in a worldwide sample of modern human populations. Our analyses reveal that not all traits are equally well-suited for reconstructing population affinities. Whereas some traits largely reflect neutral variation and therefore evolved primarily as a result of genetic drift, others can be linked to nonstochastic processes such as natural selection or hominin admixture. We also demonstrate that reconstructions of population affinity based on many traits are not necessarily more reliable than those based on only a few traits. Importantly, we find a set of highly diagnostic trait combinations that preserve neutral genetic signals best (up to [Formula: see text] r = 0.580; 95% r range = 0.293 to 0.758; P = 0.001). We propose that these trait combinations should be prioritized in future research, as they allow for more accurate inferences about past human population dynamics when using dental morphology as a proxy for DNA.

Mitochondrial genomes from Bronze Age Poland reveal genetic continuity from the Late Neolithic and additional genetic affinities with the steppe populations.

In this work we aim to investigate the origins and genetic affinities of Bronze Age populations (2,400-1,100 BC) from the region of southern Poland and to trace maternal kinship patterns present in the burials of those populations by the use of complete mitochondrial genomes. We performed ancient DNA analyses for Bronze Age individuals from present-day Poland associated with the Strzyżow culture, the Mierzanowice culture, and the Trzciniec Cultural circle. To obtain complete mitochondrial genomes, we sequenced genomic libraries using Illumina platform. Additionally, hybridization capture was used to enrich some of the samples for mitochondrial DNA. AMS 14 C-dating was conducted for 51 individuals to verify chronological and cultural attribution of the analyzed samples. Complete ancient mitochondrial genomes were generated for 80 of the Bronze Age individuals from present-day Poland. The results of the population genetic analyses indicate close maternal genetic affinity between Mierzanowice, Trzciniec, and Corded Ware culture-associated populations. This is in contrast to the genetically more distant Strzyżów people that displayed closer maternal genetic relation to steppe populations associated with the preceding Yamnaya culture and Catacomb culture, and with later Scythians. Potential maternal kinship relations were identified in burials of Mierzanowice and Trzciniec populations analyzed in this study. Results revealed genetic continuity from the Late Neolithic Corded Ware groups to Bronze Age Mierzanowice and Trzciniec-associated populations, and possible additional genetic contribution from the steppe to the formation of the Strzyżów-associated group at the end of 3rd millennium BC. Mitochondrial patterns indicated several pairs of potentially maternally related individuals mostly in Trzciniec-associated group.

Genetic variation and population structure analysis of Chinese Wuzhong Hui population using 30 Indels

Background: Insertions and deletions (Indels) have been used in routine forensic studies, archaeology, and population genetics. They have certain advantages, such as absence of stutter, small amplicon lengths, and low mutation rates. The genetic variations and forensic features of Indels in the Wuzhong Hui population are, as yet, unclear.Aim: To investigate the genetic polymorphisms of 30 Indels in Wuzhong Hui people and explore their genetic relationship with 48 reference populations from all over the world.Subjects and methods: We genotyped 30 Indels included in the Investigator DIPplex Kit in 156 Wuzhong Hui individuals. The genetic polymorphisms and population genetic relationships were analysed and explored via pairwise Fst, principal component analysis, multidimensional scaling plots, phylogenetic tree, and structure.Results: The combined power of discrimination (CPD) and the combined probability of exclusion (CPE) were 0.9999999999899 and 0.9880, respectively. Population genetic diversity and affinity were associated with geographic origin and linguistic affiliation.Conclusions: The 30 Indels can be utilised as an important tool in forensic personal identification and as a supplementary method in paternity testing in Wuzhong Hui. The Wuzhong Hui people have a close genetic relationship with populations of geographical proximity and Sinitic-speaking populations, while they are different from other continental populations and Turkic-speaking populations.

The genetic affinities of Gujjar and Ladakhi populations of India

The Union Territories of Jammu and Kashmir (J&K) and Ladakh in North India owing to their unique geographic location offer a wide variety of landscape from plains to high altitudes and is a congruence of many languages and cultural practices. Here, we present the genetic diversity studies of Gujjars from Jammu region of J&K and Ladakhi population based on a battery of autosomal single nucleotide polymorphisms (SNPs) and short tandem repeats (STRs), Y-chromosomal STRs and the control region of the mitochondrial genome. These two populations were observed to be genetically distant to each other as well as to other populations from India. Interestingly, Y-STR analyses showed a closer affinity of Gujjars to other nomadic populations of Pashtuns from Baghlans and Kunduz provinces of Afghanistan and Pashtuns and Sindhis of Pakistan. Gujjars exhibited lesser genetic diversity as compared to Ladakhi population. M30f and M9 were the most abundant mitochondrial haplogroups observed among Gujjars and Ladakhis, respectively. A lower matrilineal to patrilineal diversity was observed for both these populations. The current study presents the first comprehensive analysis of Gujjars and Ladakhis and reveals their unique genetic affiliations with other populations of the world.

Genetic diversity of the rain tree (Albizia saman) in Colombian seasonally dry tropical forest for informing conservation and restoration interventions.

Albizia saman is a multipurpose tree species of seasonally dry tropical forests (SDTFs) of Mesoamerica and northern South America typically cultivated in silvopastoral and other agroforestry systems around the world, a trend that is bound to increase in light of multimillion hectare commitments for forest and landscape restoration. The effective conservation and sustainable use of A. saman requires detailed knowledge of its genetic diversity across its native distribution range of which surprisingly little is known to date. We assessed the genetic diversity and structure of A.saman across twelve representative locations of SDTF in Colombia, and how they may have been shaped by past climatic changes and human influence. We found four different genetic groups which may be the result of differentiation due to isolation of populations in preglacial times. The current distribution and mixture of genetic groups across STDF fragments we observed might be the result of range expansion of SDTFs during the last glacial period followed by range contraction during the Holocene and human‐influenced movement of germplasm associated with cattle ranching. Despite the fragmented state of the presumed natural A. saman stands we sampled, we did not find any signs of inbreeding, suggesting that gene flow is not jeopardized in humanized landscapes. However, further research is needed to assess potential deleterious effects of fragmentation on progeny. Climate change is not expected to seriously threaten the in situ persistence of A. saman populations and might present opportunities for future range expansion. However, the sourcing of germplasm for tree planting activities needs to be aligned with the genetic affinity of reference populations across the distribution of Colombian SDTFs. We identify priority source populations for in situ conservation based on their high genetic diversity, lack or limited signs of admixture, and/or genetic uniqueness.

Estimation of sex from metatarsals using discriminant function and logistic regression analyses

ABSTRACT South Africa has one of the highest crime rates in the world and the discovery of dismembered bodies for human identification process poses a greater challenge. The South African Africans (also known as South African blacks) population group is often the victims of crimes as they are the largest group. While measurements of several bones of the human skeleton have been used for sex estimation, the potential of metatarsals have not been explored in this population group. Metatarsal bones are usually well-preserved since they are recovered in shoes protected from scavengers and they are able to withstand environmental degradation and taphonomy. This study investigated the potential of measurements of metatarsals in sex estimate amongst South African Africans using logistic and discriminant function analysis. Six measurements of metatarsals from 100 individuals of known sex and population affinity from the Raymond Dart Collection of Human skeletons were analysed. Various combinations of measurements of metatarsal bones yielded suitably high average accuracies (79% to 84%) for sex estimation and are comparable to functions derived from other skeletal elements of South African Africans. Metatarsals of South African Africans are therefore useful as alternatives to highly sexual dimorphic bones in the forensic estimation of sex.

Mesolithic Human Teeth from Zamostye-2, Moscow Region

We describe the morphology of deciduous and permanent human teeth from Zamostye-2—a Mesolithic site in the Moscow Region, Russia. Pathological changes indicate a variable diet, including both animal and vegetable food. Non-metric analysis reveals several Upper Paleolithic retentions, but the overall combination is insufficient for tracing population affinities. Metrically, permanent teeth from Zamostye are similar to those from the Mesolithic burial ground on Yuzhny Oleny (Southern Reindeer) Island, Karelia, while differing from the teeth of Mesolithic Western and Southern Europeans. Our findings agree with those of recent genetic studies that revealed close affinities between the Mesolithic populations of European Russia, contrasting them with the Mesolithic groups of Western and Northern Europe.

Genetic Affinities among Southern Africa Hunter-Gatherers and the Impact of Admixing Farmer and Herder Populations.

Southern African indigenous groups, traditionally hunter-gatherers (San) and herders (Khoekhoe), are commonly referred to as “Khoe-San” populations and have a long history in southern Africa. Their ancestors were largely isolated up until ∼2,000 years ago before the arrival of pastoralists and farmers in southern Africa. Assessing relationships among regional Khoe-San groups has been challenging due to admixture with immigrant populations that obscure past population affinities and gene flow among these autochthonous communities. We re-evaluate a combined genome-wide data set of previously published southern Africa Khoe-San populations in conjunction with novel data from Khoe-San individuals collected in Xade (Central Kalahari Game Reserve, Botswana) prior to their resettlement outside the reserve. After excluding regions in the genome that trace their ancestry to recent migrant groups, the genetic diversity of 20 Khoe-San groups fitted an isolation-by-distance model. Even though isolation-by-distance explained most genetic affinities between the different autochthonous groups, additional signals of contact between Khoe-San groups could be detected. For instance, we found stronger genetic affinities, than what would be explained by isolation-by-distance gene flow, between the two geographically separated Khoe-San groups, who speak branches of the Kx’a-language family (ǂHoan and Ju). We also scanned the genome-wide data for signals of adaptive gene flow from farmers/herders into Khoe-San groups and identified a number of genomic regions potentially introduced by the arrival of the new groups. This study provides a comprehensive picture of affinities among Khoe-San groups, prior to the arrival of recent migrants, and found that these affinities are primarily determined by the geographic landscape.

Examining Cranial Morphology of Asian and Hispanic Populations Using Geometric Morphometrics for Ancestry Estimation

Poor classification trends of Hispanic individuals have been shown when using the statistical software Fordisc 3.1 (FD3), which is commonly used by practitioners to estimate ancestry for unidentified skeletal cases (Jantz & Ousley 2005; Ousley & Jantz 2012). Similarities in craniometric dimensions were identified between Asian and Hispanic groups when performing discriminant function and canonical variate analysis using FD3 (Dudzik & Jantz 2016; Jantz & Ousley 2005). Hispanic cases were shown to often classify as Asian and showed a particularly close relationship with Japanese individuals, as illustrated by small Mahalanobis distances. This study further explores these misclassification trend findings by comparing craniometric analyses with geometric morphometric approaches to better identify morphological overlap between Asian and Hispanic populations. Geometric morphometric analyses have become increasingly useful for studies of cranial shape, and inter-landmark distances have been shown to more accurately estimate population affinity than standard cranial measurements (Spradley & Jantz 2016). Based on this evidence, a more detailed analysis of the morphological similarities between Asian and Hispanic craniometrics is warranted using geometric morphometric approaches. Data sets used include coordinate data of a subset of the Hispanic sample included in FD3 as well as individuals from Japan, Thailand, Korea, and China. Results show that variation among samples can be better identified to describe which dimensions of the cranium exhibit the most overlap across populations. Specifically, comparisons between the Asian and Hispanic data showed that the position of landmarks mainly representing dimensions of the neurocranium are useful for accurately predicting group membership.

Sex estimation of femur using simulated metapopulation database: A preliminary investigation

Accurate and reliable methods of sex estimation are essential in forensic practice. In the literature, both the population based and non-population specific standards are existing. In the present work, the summary statistics of 3 femoral standard measurements (joints and length diameters) were collected from 13 published studies of modern populations. The metric data of each population were regenerated using truncated normal distribution approach. A simulated metapopulation database was constructed using the combined metric data of 2275 femur bones. Despite interpopulation differences, the calculation of stable non-population specific discriminant functions (DF) was possible using the most discriminatory variables selected by stepwise analysis.The functions were tested on raw data of 6 populations which were obtained from authentic sources. The pooled DFs produced lower but comparable accuracies to the population specific functions using fewer number of variables. The total allocation accuracies of the temporally distant Terry collection did reach better than 90% in both American whites and blacks while in the contemporary Turkish and Hispanic samples were more than 85%. In Asian populations, the total accuracies ranged from 69.7% to 84.9%. Nevertheless, raising the posterior probability threshold to 0.95 increased the total allocation accuracies above 95% in all populations using the pooled populations function of femur joints diameters. This function permitted the classification of one third to more than half of the total sample size in each population which suggest a considerable practical value in estimating sex of unknown individuals without a priori recognition of population affinity.

Using the shape of the basicranial portion of the temporal bone to distinguish between relatively closely-related human populations

Variation in cranial morphology is routinely used in archaeology to identify population affinity in human skeletal remains. The shape of the external basicranial portion of the temporal bone, in particular, has been found to have one of the strongest phylogenetic signals in the crania, and so it can be effectively used to distinguish between populations on a large, often global scale. However, its applicability to the analysis of relatively closely-related groups remains largely unexplored. The retention of population signatures in the shape of this portion of the temporal bone is particularly useful for archaeology, as the fragility of the cranium makes analysis of its shape in entirety often difficult. If the shape of the temporal bone can identify differences between relatively closely-related populations with a similar accuracy as for more distantly-related populations, this would significantly aid analyses of population history on a local scale. To test this, we initiated a study that used three-dimensional geometric morphometrics to investigate the shape variation of the temporal bone of two British archaeological populations that were separated both temporally and geographically. The results of a MANOVA found statistically significant shape differences between the two populations and a DFA found that the shape of the temporal bone can correctly classify 84.7% of individuals into their respective population. Therefore, the findings of this study suggest that the shape of the temporal bone can accurately identify differences between two relatively closely-related populations. Future research should focus on examining larger samples from a greater number of populations to determine whether this pattern is widespread.

Parasitic relationship of Cistanche deserticola and host-plant Haloxylon ammodendron based on genetic variation of host

ObjectiveCistanche deserticola is a famous and endangered medicinal plant that is parasitic upon Haloxylon ammodendron with rather low parasitic rates. It is important to find high affinity germplasms for increasing the survival of C. deserticola. However, little is known in genetic variation and high affinity populations of H. ammodendron in China. MethodsIn this study, 98 accessions of H. ammodendron seeds were collected from five regions covering almost the entire natural distribution of H. ammodendron in China. Their genetic variations were analyzed using AFLP and ITS by the maximum parsimony method, and a dendrogram was constructed using the unweighted pair-group method with arithmetic average (UPGMA). The parasitic rates of C. deserticola on different accessions of H. ammodendron were calculated in the field experiment. ResultsBoth AFLP and ITS methods consistently revealed that there was a high level of genetic diversity in the natural populations of H. ammodendron. Hierarchical population structure analysis uncovered a clear pattern that all populations were grouped into three main clusters, and eight populations from eastern region were genetically clustered together. These regions were significantly differentiated (P < 0.05), 13.10% of variation occurred among populations, and 86.90% within populations was revealed by analysis of molecular variance (AMOVA). The populations of Inner Mongolia had the highest parasitic rates followed by Ganjiahu Reserve and Yongning Plantation for the top three, which were not completely related to the genetic variation. ConclusionGenetic characteristics of H. ammodendron in China were clarified and the order of affinity of different populations was given, which were primers for discovering high affinity germplasms.

PS1579 AN EPIDEMIOLOGIC STUDY OF PREGNANCY RELATED VENOUS THROMBO‐EMBOLISM IN SOUTH AFRICA: ARE HIV INFECTED WOMEN A NEW HIGH‐RISK GROUP?

Background:Venous thrombo‐embolism (VTE) is an important cause of preventable morbidity and mortality in pregnancy. While much consideration has been given to inherited thrombophilias and a past history of VTE, epidemiologic studies to date have not examined the significance of human immunodeficiency virus (HIV) as a potential risk factor for pregnancy and postpartum related VTE. In South Africa this is of particular concern, considering that approximately one‐third of women attending antenatal clinics are HIV infected.Aims:A study was therefore performed at a single academic centre to investigate the clinical spectrum, incidence and risk factors for VTE in pregnancy and the puerperium in a population of Black South African women in order to guide evidence‐based thromboprophylaxis.Methods:A case control study of first time VTE during pregnancy or within 42 days postpartum was conducted between January and December 2018. A control group (n = 295) matched for population affinity and gestation were recruited. The medical records were reviewed for 30 baseline antepartum and/or postpartum risk factors for VTE. Statistical comparisons were performed using Fisher's exact test with calculation of odds ratios (OR) and 95% confidence intervals (CI). The study was approved by the Human Research Ethics Committee of the University of the Witwatersrand (M181018).Results:59 patients with the diagnosis of VTE in pregnancy or the puerperium were identified during the study period (34 with deep vein thrombosis, 23 with pulmonary embolus and two with both). The total number of deliveries during the study period was 8 361, giving an incidence of 4.4 per 1000 deliveries. In the multivariate analysis, HIV infection was associated with a four‐fold increased risk for VTE among pregnant and postpartum women (95% CI, 1.97‐ 6.63, P &lt; 0.001). In addition, medical co‐morbidities, in particular peripartum cardiomyopathy, (OR, 11.04, 95% CI, 3.90–31.25), pre‐eclampsia with foetal growth restriction (OR, 6.88, 95% CI, 1.91–24.79), preterm delivery (OR, 7.60, 95% CI, 2.80–20.62), caesarean delivery in labour (OR, 3.17, 95% CI, 1.13–8.87), postpartum haemorrhage (OR, 22.60, 95% CI, 5.75–88.84) and prolonged hospital admission (OR, 7.78, 95% CI, 2.38–25.45) were independent risk factors for VTE. In 41 women thrombophilia screening was performed. Protein S deficiency was confirmed in five patients (three of which were HIV infected with virologic suppression) and the prothrombin gene mutation (not the classic G20210A mutation) was confirmed in a single patient.Summary/Conclusion:This study demonstrated that the incidence of VTE complicating pregnancy in Black South Africans is higher than the reported prevalence in White and Asian population groups. The findings of this study support many of the existing guideline recommendations and may provide valuable information to local obstetricians for identifying high‐risk pregnant and postpartum women requiring thromboprophylaxis. In addition, HIV emerged as a significant risk factor for VTE in this study population.

Development and characterization of polymorphic microsatellite markers in northern fulmar, Fulmarus glacialis (Procellariiformes), and cross-species amplification in eight other seabirds.

In the North Pacific, northern fulmar (Fulmarus glacialis) forms extensive colonies in few locales, which may lead to limited gene flow and locale-specific population threats. In the Atlantic, there are thousands of colonies of varying sizes and in Europe the species is considered threatened. Prior screens and classical microsatellite development in fulmar failed to provide a suite of markers adequate for population genetics studies. The objective of this study was to isolate a suite of polymorphic microsatellite loci with sufficient variability to quantify levels of gene flow, population affinity, and identify familial relationships in fulmar. We also performed a cross-species screening of these markers in eight other species. We used shotgun sequencing to isolate 26 novel microsatellite markers in fulmar to screen for variability using individuals from two distinct regions: the Pacific (Chagulak Island, Alaska) and theAtlantic (Hafnarey Island, Iceland). Polymorphism was present in 24 loci in Chagulak and 23 in Hafnarey, while one locus failed to amplify in either colony. Polymorphic loci exhibited moderate levels of genetic diversity and this suite of loci uncovered genetic structuring between the regions. Among the other species screened, polymorphism was present in one to seven loci. The loci yielded sufficient variability for use in population studies and estimation of familial relationships; as few as five loci provide resolution to determine individual identity. These markers will allow further insight into the global population dynamics and phylogeography of fulmars. We also demonstrated some markers are transferable to other species.

Sex and ancestry related differences between two Central European populations determined using exocranial meshes

Assessing sex and population affinity is an important part of the process of biologically identifying unknown human remains, and the skull is usually one of the best structures for assessing both these components of the biological profile. Population affinity is known to be a hugely important variable when estimating sex because the manifestation of sexually dimorphic traits, body size or social and behavioural habits differs across populations. Therefore, for forensic purposes, the estimation of ancestry is a necessary step in the identification of bone remains. The present study improves on the results of a previously developed virtual method using the exocranial surface for sex estimation and assessing population affinity. The ability to assess these components of the biological profile was successfully tested on 208 individuals from two recent European populations. The original classifier was based on geometric morphometric analyses (CPD-DCA, PCA, SVM) and was able to assess the sex of individuals belonging to one French population with an accuracy exceeding 90 % Musilová et al. [1]. To improve the reliability of the method, the Czech population sample was added to the dataset, yielding the highest accuracy of 96.2 %; using the combined dataset, the reliability of the method was 91.8 %. Secondly, we used the same method utilizing inter-population differences to classify individuals based on the shape of the skull. The greatest accuracy rate was 92.8 %, which makes our method a promising tool for sex estimation and assessing population affinity.

The accuracy of the Transition Analysis of aging on a heterogenic South African population

Transition Analysis (TA) is an age estimation method for adult skeletons at death, using three skeletal traits together, namely, the cranial sutures (CS), the pubic symphyses (PS) and the auricular surfaces (AS). In forensic anthropology, estimating age at death is vital for positive identification of an individual; however, differences in skeletal elements have been observed between sex and population affinity. The aim of this study was to determine how accurately the TA could be applied to a population that differed from the original reference samples.Scoring methods, described by the authors of this analysis, were used to age individuals (n = 290) in the South African (SA) Mixed Ancestry population, which is a heterogenic population, consisting of many gene pools from different population groups. The results were compared to the actual ages of the skeletal remains, obtained through cadaver records, and the most likely age calculated by the TA, as well as age estimation by means of the three skeletal elements individually.Results showed that there was a significant correlation between the actual and estimated ages of the study population (Pearson correlation coefficient: 0.58). The AS was the most accurate trait, whereas the PS was the least accurate trait. In addition, females’ estimated ages were more accurate than males. These findings correlated with other authors in terms of the significance of the TA when applied to different populations; however, the individual trait correlations were in disagreement with other authors. The results of this study are an important contribution to anthropological literature as they indicate that there are differences between populations and sex when determining age, but that the TA is still applicable for analysis on this heterogenic population.

Siberian genetic diversity reveals complex origins of the Samoyedic-speaking populations.

We examined autosomal genome-wide SNPs and Y-chromosome data from 15 Siberian and 12 reference populations to study the affinities of Siberian populations, and to address hypotheses about the origin of the Samoyed peoples. Samples were genotyped for 567 096 autosomal SNPs and 147 Y-chromosome polymorphic sites. For several analyses, we used 281 093 SNPs from the intersection of our data with publicly available ancient Siberian samples. To examine genetic relatedness among populations, we applied PCA, FST , TreeMix, and ADMIXTURE analyses. To explore the potential effect of demography and evolutionary processes, the distribution of ROH and IBD sharing within population were studied. Analyses of autosomal and Y-chromosome data reveal high differentiation of the Siberian groups. The Siberian populations have a large proportion of their genome in ROH and IBD segments. Several populations (ie, Nganasans, Evenks, Yukagirs, and Koryaks) do not appear to have experienced admixture with other Siberian populations (ie, producing only positive f3), while for the other tested populations the composition of mixing sources always included Nganasans or Evenks. The Nganasans from the Taymyr Peninsula demonstrate the greatest level of shared shorter ROH and IBD with nearly all other Siberian populations. Autosomal SNP and Y-chromosome data demonstrate that Samoyedic populations differ significantly in their genetic composition. Genetic relationship is observed only between Forest and Tundra Nentsi. Selkups are affiliated with the Kets from the Yenisey River, while the Nganasans are separated from their linguistic neighbors, showing closer affinities with the Evenks and Yukagirs.