Craniometric Variation Research Articles

Craniometric variation and the ancestry of modern humans.

Ancient and contemporary DNA provide information about geographic variation in the ancestry of present-day humans. All living populations have ancestry from early Homo sapiens originating in sub-Saharan Africa. Populations of Eurasian descent also have a small amount of Neandertal ancestry. This study examines whether craniometric distances between recent modern human samples reflect this geographic variation in ancestry. Among recent modern humans, Eurasians are expected to be more similar to Neandertals, whereas both sub-Saharan Africans and Eurasians are expected to be equidistant from early H. sapiens. Data on 33 craniometric traits from 2524 recent modern humans were compared with data from the literature for Neandertals and early H. sapiens. Mahalanobis distances were computed for each modern specimen to both the Neandertal and early H. sapiens means. These distances were examined for differences between recent humans from sub-Saharan Africa (N = 373) and those of Eurasian descent (N = 2151). Eurasians as a group are significantly closer than sub-Saharan Africans to Neandertals. There is no significant difference between the distances of sub-Saharan Africans and Eurasians to early H. sapiens. The differences between sub-Saharan Africans and Eurasians for both Neandertals and early H. sapiens are as expected. Although there has been geographic differentiation among recent modern humans, including differences in Neandertal admixture, these differences have not affected overall similarity of recent modern sub-Saharan Africans and Eurasians to the earliest samples of H. sapiens.

A Craniometric Analysis of the Subfamily Cervinae (Cervidae, Mammalia)

This study employs Principal Component Analysis to examine cranial measurements from both extant and fossil specimens spanning 38 species and comprising over 300 individuals within the subfamily Cervinae. Our findings elucidate craniometric distinctions among cervids characterized by varying body sizes and certain evolutionary adaptations. While our results generally corroborate previous assertions regarding the limited craniometric variability among plesiometacarpal deer, they also unveil specific cranial adaptations within certain genera and species. The Principal Component Analysis of craniometric data revealed that giant and large-sized deer display significantly broader ecomorphological diversity in cranial shape compared to small-sized deer. Secondly, small-sized deer exhibit greater uniformity in their cranial shape, appearing densely clustered on the factorial map. Thus, we conclude that body size imposes ecological constraints, limiting the available niches due to eco-physiological factors. This study demonstrates that endemic insular deer do not evolve consistent craniometric features attributable to insular isolation, while the cranial proportions of medium-to-small-sized deer delineate a ubiquitous morphological archetype characteristic of numerous cervid taxa spanning diverse phylogenetic lineages and sharing comparable body sizes. This group of “Dama-like” deer, characterized by similar body size, metabolic rates, ecological needs, and cranial morphometry, is referred to here as the fundamental eco-physiological type, typical of warm regions within the Palearctic and Oriental biogeographic realms.

Craniometric variation and taxonomic boundaries in the Madras Treeshrew (Scandentia, Tupaiidae: Anathana ellioti [Waterhouse, 1850]) from India

The Madras Treeshrew, Anathana ellioti (Waterhouse, 1850), is a small, poorly studied mammal from South Asia. It is the only treeshrew found across the southern half of the Indian subcontinent and is the westernmost member of its order (Scandentia). The phylogenetic relationship between Anathana and its putative sister genus, Tupaia, remains unresolved, and the morphological differences between these two genera have yet to be analyzed with craniometric data. Here we describe some features that distinguish Anathana from other treeshrews. However, our comparative morphometric analyses reveal that Anathana overlaps with Tupaia in morphospace; it is smaller than most species (including the only other species found on the Indian mainland, T. belangeri) but larger than T. minor, Dendrogale melanura, and Ptilocercus lowii. At the infraspecific level, there is some separation between eastern and western populations, but this requires further investigation with larger sample sizes. Unfortunately, Anathana is disproportionately scarce in museum collections relative to other scandentians, and additional biological surveys across South India will be critical for future research on the taxonomy, distribution, and conservation of this elusive taxon.

Межгрупповая изменчивость краниометрических характеристик населения Средней Азии в 1500-летней ретроспективе (VII в. до н.э. – VIII в. н.э.)

Introduction. The paper revisits the intergroup craniometric variability in the Early Iron Age, Antiquity and Early medieval Central Asian population. Some new cranial materials are considered within the hierarchical system of the regional populations. Materials and methods. The comparison included 61 cranial samples from all historical and cultural regions of Central Asia with a total of 1100 crania. 12 standard measurements of the facial skeleton were used. First, we conducted Canonical discriminant analysis. Second, the matrix of Mahalanobis D2 distances was obtained using the resulting group coordinates in the space of the canonical vectors. Finally, the distance matrix was subjected to Multidimensional scaling and the Ward’s hierarchical cluster analysis. Results. The first three canonical variates reflect 53.4% of the total intergroup variation and differentiate samples based on bizygomatic breadth, orbit dimensions, nasal bridge height (and width to a lesser extent), horizontal profiling angles and nose protrusion angle. Upper facial height also contributes to intergroup craniometric variability but does not play a decisive role in differentiating among samples of European ancestry in the considered chronological period. Correlation coefficients between canonical variables and multidimensional scaling coordinates suggest similar relative positions of the groups in the scatterplots. Discussion. Considering the mixed nature of the Central Asian population and the difficulty of objective differentiation of morphological types, we caution against unreflective use of terms “East Mediterranean type” and “Pamir-Fergana race”. The results suggest that the Antiquity and Early medieval sedentary populations are difficult to distinguish from nomadic and semi-nomadic groups of the Wusun period. The new materials confirm the morphological similarity between Early medieval population of Sogdiana (ancient Panjakent) and Ushrusana (Kurkat dakhmaks). @ 2023. This work is licensed under a CC BY 4.0 license

Craniometric variability of Canis lupus, Carnivora, Canidae in the centre of European Russia

Craniometric variability of Canis lupus, Carnivora, Canidae in the centre of European Russia

Craniometric Variability of the Common Shrew (Sorex araneus, Eulipotyphla) in the Northeastern Part of European Russia: Effects of Various Factors

Craniometric variability of the common shrew has been studied on 613 skulls of young (first summer of life) individuals from ten localities in the northeastern part of European Russia, i.e., Komi Republic and Nenets Autonomous Okrug. We have compared 16 skull traits. The impact of various factors on cranial variability of the species is discussed. We found significant interpopulation variability in the skull size. The morphological distances (Mahalanobis distances) between samples within a race were often greater than those between samples of different races. Several skull traits were found specific to some races. Both latitude and elevation were shown to affect the interpopulation variability significantly. A decrease in the size of skulls was revealed towards the north versus an increase with altitude. Estimation of the contribution of a certain factor was complicated by the joint effect of various factors in various combinations.

Variation in Features of the Cranium of the Musk Deer Moschus moschiferus L. in Different Phases of the Population Cycle

The variation in four characters (three craniometrical and one nonmetric with supplemental bones) was investigated in 105 craniums of musk deer in different phases (depression and growth) of the population cycle from the East Sayan mountains. The duration of the cycle was 50 years, which corresponds to ten generations of animals. The results obtained show the multidirectional relation of skull sizes (craniometric variation) with phases in the population number in animals of different sexes. The variability of nonmetric characteristics of the skull is characterized by the greatest frequency of manifestation and the maximum quantity of additional bones during the phase of population depression in animals of both sexes, a gradual decrease in their quantity during the growth phase, and then complete loss of supplemental bones when there is an increase in population numbers. The revealed phene of the skull is a key cranial variation and may be used as a way for monitoring natural populations of rare and disappearing subspecies of musk deer.

Precipitation and vegetation shape patterns of genomic and craniometric variation in the central African rodent Praomys misonnei.

Predicting species' capacity to respond to climate change is an essential first step in developing effective conservation strategies. However, conservation prioritization schemes rarely take evolutionary potential into account. Ecotones provide important opportunities for diversifying selection and may thus constitute reservoirs of standing variation, increasing the capacity for future adaptation. Here, we map patterns of environmentally associated genomic and craniometric variation in the central African rodent Praomys misonnei to identify areas with the greatest turnover in genomic composition. We also project patterns of environmentally associated genomic variation under future climate change scenarios to determine where populations may be under the greatest pressure to adapt. While precipitation gradients influence both genomic and craniometric variation, vegetation structure is also an important determinant of craniometric variation. Areas of elevated environmentally associated genomic and craniometric variation overlap with zones of rapid ecological transition underlining their importance as reservoirs of evolutionary potential. We also find that populations in the Sanaga river basin, central Cameroon and coastal Gabon are likely to be under the greatest pressure from climate change. Lastly, we make specific conservation recommendations on how to protect zones of high evolutionary potential and identify areas where populations may be the most susceptible to climate change.

Estudio ecomorfológico de la variación craneana en poblaciones prehistóricas de Perú

El objetivo del presente trabajo es analizar la variación craneométrica en una muestra de individuos del Holoceno temprano/medio al tardío de Perú. Para esto, se registraron 8 medidas lineales en el esqueleto facial y bóveda craneana de 301 individuos procedentes de 19 sitios arqueológicos, los cuales se encuentran ubicados en 4 biomas. Se exploró la variación en la forma y tamaño del cráneo entre individuos de distintos biomas y sitios arqueológicos mediante un Análisis de Componentes Principales y Análisis Discriminante. Complementariamente, se evaluó la afinidad morfológica entre las muestras mediante el cálculo de distancias de Mahalanobis y un análisis de clúster jerárquico de Ward. Asimismo, se estimó el efecto del bioma, sitio arqueológico, altitud, y cronología para explicar el patrón de variación morfológico observado a través de MANOVA. Los resultados mostraron que existen similitudes entre individuos de distintas cronologías; los individuos del Holoceno temprano/medio presentan gran variación morfológica; las muestras más recientes presentan diferencias en la longitud del cráneo, variables que describen la apertura nasal, pero también el subcomponente alveolar, lo cual a su vez se encuentra asociado a la diversidad de altitud y sitio arqueológico de procedencia. Se discuten los resultados en relación a trabajos previos que estudiaron muestras de Perú, y otras áreas de América del Sur. De esta manera se espera contribuir a la discusión de los debates actuales sobre el poblamiento de Sudamérica, especialmente en torno a las posibles adaptaciones locales.

Photogrammetric analysis of nasofacial angle among the Urhobo subjects

Background: All known anthropometric angles are evidently characterized by the feature of structural and functional variation according to gender, ethnic, and ecological influences. Knowledge of craniometric variation in the nasofacial angle among the Urhobo subjects appears limited, prompting the conduct of this study. Aim: The aim of the current anthropometric study was to evaluate a sample population of Urhobo subjects, by photogrammetric techniques, to establish the normal value of their nasofacial angle, and its associated variation. Materials and Methods: The noninvasive technique of angular photogrammetry was adopted for this investigation. This method incorporates the use of angular analysis of standardized left lateral facial cephalograms of 1000 Urhobo subjects, between 18 and 60 years of age. Selected craniofacial landmarks include the glabella, nasion, and nasal dorsum. Results: Descriptive analysis of data obtained from sampled Urhobo subjects revealed a mean nasofacial angle of 39.81° ± 4.81° and 39.45° ± 4.04° for males and females, respectively. Obtained means were not gender-specific on t- test analysis. Conclusion: While research findings did not demonstrate statistically significant gender differences, the obtained results would still have beneficial forensic and archaeological applications in reaching conclusions regarding subject identity, particularly in scientific expeditions in the politically volatile study area.

Craniometric variation and ancestry estimation in two contemporary Caribbean populations

Ancestry estimation of skeletonized remains by forensic anthropologists is conducted through comparative means, and a lack of population-specific data results in possible misclassifications. This is especially germane to individuals of Latin American ancestry. Generally, each country in Latin America can trace their ancestral lineage through three main parental groups: Indigenous, European, and African. However, grouping all Latin American individuals under the broad “Hispanic” category ignores the specific genetic contributions from each parental group, which is variable and dependent on the population histories and sociocultural dynamics of each country. This study analyzes the craniometric ancestry of Hispaniola (the Dominican Republic and Haiti) using 190 cranial Computed Tomography (CT) scans (f=103; m=87), along with the island’s history, to explore similarities and differences between the two groups. MANOVA results indicate that 53.6% and 71.4% of the 28 cranial measurements differ between the ancestries and sexes, respectively; and intraobserver error analyses demonstrate that 85.7% of measurements from CT scans are good-excellent in reliability. Further, a total of 12 canonical discriminant function analyses produced cross-validated classification accuracies of 73.7–78.6% for females, 71.8–87.5% for males, and 72.0–77.8% for pooled sex. This study demonstrates that, despite sharing a small island, Dominican and Haitian individuals can be differentiated with a fair amount of statistical certainty, which is possible due to complex socio-cultural, -political, and -demographic factors that have produced and maintained genetic heterogeneity. Moreover, the discriminant functions provided here can be used by the international forensic science community to identify individuals living on Hispaniola.

Virtual reconstruction of the Upper Palaeolithic skull from Zlatý Kůň, Czech Republic: Sex assessment and morphological affinity.

The incomplete cranium discovered at the Zlatý kůň site in the Bohemian Karst is a rare piece of skeletal evidence of human presence in Central Europe during the Late Glacial period. The relative position of cranial fragments was restored and missing parts of the cranium were virtually reconstructed using mirroring and the Thin-plate splines algorithm. The reconstruction allowed us to collect principal cranial measurements, revise a previous unfounded sex assignment and explore the specimen’s morphological affinity. Visual assessment could not reliably provide a sexual diagnosis, as such methods have been developed on modern populations. Using a population-specific approach developed on cranial measurements collected from the literature on reliably sexed European Upper Palaeolithic specimens, linear discriminant analysis confirmed previous assignment to the female sex. However, caution is necessary with regard to the fact that it was assessed from the skull. The Zlatý kůň specimen clearly falls within the range of Upper Palaeolithic craniometric variation. Despite the shift in cranial variation that accompanied the Last Glacial Maximum (LGM), the Zlatý kůň skull exhibits a morphological affinity with the pre-LGM population. Several interpretations are proposed with regard to the complex population processes that occurred after the LGM in Europe.

Craniometric variation among Brazilian and Scottish populations: a physical anthropology approach

Aim: The present investigation intended to compare the craniometric variations of two samples of different nationalities (Brazilian and Scottish). Materials and methods: The Brazilian sample consisted of 100 modern complete skulls, including 53 female skulls and 47 male skulls, and the Scottish sample consisted of 100 historical skulls (61 males, 39 females) and 36 mandibles (24 males, 12 females). The cranial measurement protocol was composed of 40 measurements, 11 bilateral and 29 unilateral, and the measurement protocol of the mandible was composed of 15 measurements, with six that were bilateral and nine that were unique. The comparative analysis of the metric variability between the two samples was performed using the means and medians analysis, the t-test, the Wilcoxon test, and the coefficient of variance, with a significance level of 5%. Results: The results showed that, among the 72 analysed variables, 44 measurements (61.11%) presented statistical differences between the samples. The Scottish skull tends to have a cranial length (GOL diff=5.53), breadth (XCB diff=3.78) and height (NPH diff=5.33) greater than the Brazilian skulls, and the Scottish mandibles tend to show a higher mandibular ramus height (MRH diff=9.25), a higher mandibular body height (HMB diff=6.37) and a larger bigonial breadth (BGB diff=5.29) than the Brazilians. The discriminant analysis of the 51 cranial measurements and 21 mandibular measurements showed a variation of the percentage of accuracy between 46.3-83.8%. Conclusion: The metric analysis demonstrated that there is variability between the two samples studied (61,11%), but a concrete cause cannot be determined considering the multifactorial aspects of the variations of form and size.

Cranial measures and ancient DNA both show greater similarity of Neandertals to recent modern Eurasians than to recent modern sub-Saharan Africans.

Ancient DNA analysis has shown that present-day humans of Eurasian ancestry are more similar to Neandertals than are present-day humans of sub-Saharan African ancestry, reflecting interbreeding after modern humans first left Africa. We use craniometric data to test the hypothesis that the crania of recent modern humans show the same pattern. We computed Mahalanobis squared distances between a published Neandertal centroid based on 37 craniometric traits and each of 2,413 recent modern humans from the Howells global data set (N = 373 sub-Saharan Africans, N = 2,040 individuals of Eurasian descent). The average distance to the Neandertal centroid is significantly lower for Eurasian crania than for sub-Saharan African crania as expected from the findings of ancient DNA (p < 0.001). This result holds when examining distances for separate geographic regions of humans of Eurasian descent (Europeans, Asians, Australasians, Native Americans, and Pacific Islanders). Most of these results are also seen when examining distances partitioning size and shape variation. Our results show that the genetic difference in Neandertal ancestry seen in the DNA of present-day sub-Saharan Africans and Eurasians is also found in patterns of recent modern human craniometric variation.

Impacts of late Quaternary environmental change on the long-tailed ground squirrel (Urocitellus undulatus) in Mongolia.

Impacts of Quaternary environmental changes on mammal faunas of central Asia remain poorly understood due to a lack of comprehensive phylogeographic sampling for most species. To help address this knowledge gap, we conducted the most extensive molecular analysis to date of the long-tailed ground squirrel (Urocitellus undulatus Pallas 1778) in Mongolia, a country that comprises the southern core of this species’ range. Drawing on material from recent collaborative field expeditions, we genotyped 128 individuals at two mitochondrial genes (cytochrome b and cytochrome oxidase I; 1 797 bp total). Phylogenetic inference supports the existence of two deeply divergent infraspecific lineages (corresponding to subspecies U. u. undulatus and U. u. eversmanni), a result in agreement with previous molecular investigations but discordant with patterns of range-wide craniometric and external phenotypic variation. In the widespread western eversmanni lineage, we recovered geographically-associated clades from the: (a) Khangai, (b) Mongolian Altai, and (c) Govi Altai mountain ranges. Phylogeographic structure in U. u. eversmanni is consistent with an isolation-by- distance model; however, genetic distances are significantly lower than among subspecies, and intra-clade relationships are largely unresolved. The latter patterns, as well as the relatively higher nucleotide polymorphism of populations from the Great Lakes Depression of northwestern Mongolia, suggest a history of range shifts into these lowland areas in response to Pleistocene glaciation and environmental change, followed by upslope movements and mitochondrial lineage sorting with Holocene aridification. Our study illuminates possible historical mechanisms responsible for U. undulatus genetic structure and contributes to a framework for ongoing exploration of mammalian response to past and present climate change in central Asia.

Patterns of craniometric variability of six common species of shrews (Soricidae: Crocidura, Neomys, Sorex)

Patterns of craniometric variability of six common species of shrews (Soricidae: Crocidura, Neomys, Sorex)

Craniometric and epigenetic variability of the Eurasian otter (Lutra lutra) in eastern Saxony

Craniometric and epigenetic variability of the Eurasian otter (Lutra lutra) in eastern Saxony

CraMs: Craniometric Analysis Application Using 3D Skull Models.

Craniometric analysis plays an important role in anthropology studies and forensics. This paper presents CraMs, an application using a new craniometric approach based on 3D models of the skull. The main objective is to obtain, through a process supervised by anthropologists, the main points of interest used to compute craniometric measurements. The application aids this process by analyzing the skull geometry and automatically providing points of interest. The application also allows for semiautomatic point detection, where the user provides an initial guess that might be refined based on the curvature of the skull, as well as the manual selection of any other points of interest. Moreover, results comparing measurements obtained with CraMs and traditional craniometry methods on eight skulls suggest that the application provides comparable craniometric measurements and lower inter-observer variability. This approach offers advantages such as an easier access to skulls with no risk of bone damage and the possibility of defining new measurements based on morphology or other skull characteristics, which are not possible using traditional methods.

Between the Baltic and Danubian Worlds: the genetic affinities of a Middle Neolithic population from central Poland.

For a long time, anthropological and genetic research on the Neolithic revolution in Europe was mainly concentrated on the mechanism of agricultural dispersal over different parts of the continent. Recently, attention has shifted towards population processes that occurred after the arrival of the first farmers, transforming the genetically very distinctive early Neolithic Linear Pottery Culture (LBK) and Mesolithic forager populations into present-day Central Europeans. The latest studies indicate that significant changes in this respect took place within the post-Linear Pottery cultures of the Early and Middle Neolithic which were a bridge between the allochthonous LBK and the first indigenous Neolithic culture of north-central Europe—the Funnel Beaker culture (TRB). The paper presents data on mtDNA haplotypes of a Middle Neolithic population dated to 4700/4600–4100/4000 BC belonging to the Brześć Kujawski Group of the Lengyel culture (BKG) from the Kuyavia region in north-central Poland. BKG communities constituted the border of the “Danubian World” in this part of Europe for approx. seven centuries, neighboring foragers of the North European Plain and the southern Baltic basin. MtDNA haplogroups were determined in 11 individuals, and four mtDNA macrohaplogroups were found (H, U5, T, and HV0). The overall haplogroup pattern did not deviate from other post-Linear Pottery populations from central Europe, although a complete lack of N1a and the presence of U5a are noteworthy. Of greatest importance is the observed link between the BKG and the TRB horizon, confirmed by an independent analysis of the craniometric variation of Mesolithic and Neolithic populations inhabiting central Europe. Estimated phylogenetic pattern suggests significant contribution of the post-Linear BKG communities to the origin of the subsequent Middle Neolithic cultures, such as the TRB.

Craniometric analysis of European Upper Palaeolithic and Mesolithic samples supports discontinuity at the Last Glacial Maximum.

The Last Glacial Maximum (LGM) represents the most significant climatic event since the emergence of anatomically modern humans (AMH). In Europe, the LGM may have played a role in changing morphological features as a result of adaptive and stochastic processes. We use craniometric data to examine morphological diversity in pre- and post-LGM specimens. Craniometric variation is assessed across four periods—pre-LGM, late glacial, Early Holocene and Middle Holocene—using a large, well-dated, dataset. Our results show significant differences across the four periods, using a MANOVA on size-adjusted cranial measurements. A discriminant function analysis shows separation between pre-LGM and later groups. Analyses repeated on a subsample, controlled for time and location, yield similar results. The results are largely influenced by facial measurements and are most consistent with neutral demographic processes. These findings suggest that the LGM had a major impact on AMH populations in Europe prior to the Neolithic.