克什克腾旗龙头山青铜时代颅骨的人类学研究

本文对内蒙古自治区赤峰市克什克腾旗龙头山青铜时代遗址发掘出土的颅骨进行了人种学研究。１１例男性颅骨和３例女性颅骨的种族特征基本相似,均可归入现代亚洲蒙古人种的东亚人种范畴,某些特征则显示出北亚人种的影响。在若干古代和近代对比组中,龙头山青铜时代居民的体质特征分别与顺山屯青铜时代居民和近代华北居民最为接近。     

瓦窑沟青铜时代墓地颅骨的人类学特征

本文对陕西省铜川市瓦窑沟青铜时代墓葬出土的１３例颅骨进行了系统的人类学分析。结果表明,这组颅骨的种族特征可归入亚洲蒙古人种的东亚类型,同时也显示出某种程度南亚类型的影响。在近代对比组中,瓦窑沟组的基本体质类型与华北近代组、华南近代组关系最近;在古代对比组中,它与火烧沟组和殷墟中小墓②组最为接近。     

内蒙古和林格尔县将军沟墓地人骨研究

本文对内蒙古和林格尔县将军沟墓地出土的14例战国中晚期的颅骨(男性11例,女性3例)进行了人类学的观察和测量,认为该组颅骨在种族特征上可归入现代亚洲蒙古人种中的东亚人种范围。在若干古代和现代对比组中,将军沟组古代居民的体质特征与毛饮合并A组、近代华北组最为接近。     

俄罗斯远东地区特罗伊茨基靺鞨墓地人骨研究

本文对俄罗斯远东地区特罗伊茨基墓地1969年发掘出土的10例靺鞨颅骨(男性5例,女性5例)进行了人类学的观察和测量,认为该组颅骨在种族特征上可归人现代亚洲蒙古人种的范围.在若干古代和现代对比组中,特罗伊茨基组古代居民的体质特征与古代贝加尔组群、现代中央亚细亚组群和贝加尔组群较为接近.     

磨盘山遗址新石器时代人骨研究

磨盘山遗址是分布在云南省楚雄彝族自治州元谋盆地的一处新石器时代聚落。本文通过对遗址出土的6例新石器时代人骨的体质人类学研究,得出以下结论:磨盘山组颅骨的形态特征可以概括为中颅型与正颅型相结合,阔额型、阔上面型、阔鼻型、中眶型并伴有颇大的面部扁平度;磨盘山组应属于亚洲蒙古人种范畴,在次级分类比较中与南亚类型在鼻眶形态和上面部形态上表现出更多的相似性;在与亚洲蒙古人种各近代组的比较中,磨盘山组与广西壮族组关系最为密切,与蒙古组关系最为疏远;在与其他新石器对比组的比较中,磨盘山组与代表"古华南类型"的甑皮岩组、鲤鱼墩组和昙石山组表现出更多的一致性,与"古中原类型"和"古华北类型"关系疏远。     

零口战国墓颅骨的人类学特征

本文对陕西省临潼县零口村遗址发掘出土的战国秦墓颅骨的人类学特征进行了研究。该组颅骨的种族特征可归入现代亚洲蒙古人种的东亚人种范畴。在若干近代和古代对比组中 ,零口组的基本体质类型与近代华北组、新石器时代的宝鸡组和关中合并组、青铜时代的上马组和殷墟中小墓②组最为接近。     

内蒙古林西县井沟子遗址西区墓地人骨研究

本文对内蒙古林西县井沟子遗址西区墓地出土的春秋—战国时期的颅骨进行了人类学的考察,该组颅骨在种族特征上可归入现代亚洲蒙古人种中的北亚人种范围。在若干古代和现代对比组中,井沟子组古代居民的体质特征与汉代扎赉诺尔组、近代蒙古组最为接近。     

内蒙古宁城山嘴子辽墓契丹族颅骨的人类学特征

本文对内蒙古自治区赤峰市宁城县山嘴子辽代墓地出土的古代契丹族颅骨的人类学特征进行了研究。9例男性颅骨和3例女性颅骨中的大多数标本在种族特征上均可归入现代亚洲蒙古人种中的西伯利亚(北亚)人种范畴,少数标本中的个别特征则显示出某种程度上的东亚人种或北极(东北亚)人种的影响。在若干古代和近代对比组中,山嘴子辽代契丹族的体质特征分别与汉代鲜卑族和近代蒙古族最为接近。     

郑州孙庄遗址仰韶文化居民的颅骨形态

孙庄遗址位于河南省郑州市中原区孙庄村南,是分布在黄河中下游地区的一处仰韶文化晚期遗存。通过对遗址出土的10例保存基本完整的颅骨进行测量与观察后,得出以下结论：孙庄组的颅面部特征为高颅型与狭颅型相结合的颅型特点、中等偏大的面部扁平度、狭额型、中鼻型、低眶型、中面角属平颌型、犬齿窝和鼻根凹欠发达、颅顶缝简单等。孙庄组古代居民颅骨的形态特征归属于亚洲蒙古人种范围。颅骨形态学特征分析结果显示,孙庄组与亚洲蒙古人种近代华南组（R=1.26）关系最为密切,与近代蒙古组（R=1.80）和通古斯组（R=2.06）关系疏远;在与各新石器时代组的对比中,孙庄男性组与仰韶合并组（R=1.00）、庙子沟组（R=1.00）、西山组（R=1.07）、大汶口组（R=1.13）关系接近,孙庄女性组最接近于大汶口组（D_ij=3.10）、徐堡组（D_ij=4.58）和西山组（D_ij=4.60）。综上,我们可知分布在黄河中下游地区的仰韶时代中晚期人群在颅面部特征上颇为一致,具有较高的同源性,应同属于“古中原类型”居民。     

黑龙江省尼尔基库区的清代达斡尔人骨

2002年至2004年,为配合尼尔基水库的建设,黑龙江省文物考古研究所在库区内发掘了团结、全发、铁古拉三处清代达斡尔人墓葬,为研究清代嫩江流域少数民族的生活习俗、生产经济状况、社会历史等提供了重要的实物依据。本文对三处墓葬所出土的6例(男性4例,女性2例)清代达斡尔人颅骨进行体质人类学研究。该组颅骨在种族特征上可归入现代亚洲蒙古人种中的北亚人种范围,同时又与现代亚洲蒙古人种东亚类型存在着若干相似之处。在若干古代对比组中,该组达斡尔人颅骨的形态特征与山嘴子组和萧氏后族组所代表的辽代契丹人体质特征最为接近,对于研究达斡尔族族源具有一定的参考价值。     

Relationships between non-metric skeletal traits and cranial size and shape.

A long-standing controversy exists about the comparative utility of metric and non-metric traits as biological indicators in population studies. We hypothesize that the underlying scale which determines the presence or absence of a cranial non-metric trait is an expression of general and/or local size variation in the cranium. Therefore metric and non-metric traits will share a common developmental determination. The hypothesis implies that the underlying scale of a non-metric trait will be correlated with measures of cranial size and shape. Forty-eight cranial metric and twenty-five cranial non-metric traits were scored on the left side of adult male crania from four North American Indian populations. New threshold traits were generated for each non-metric trait by dichotomizing discriminant scores produced by discriminant function analysis. The discriminant analysis was performed using metric traits to discriminate between groups formed by non-metric trait presence or absence. Every non-metric trait tested was significantly correlated with its threshold trait in at least one population. The correlations were of moderate to high levels depending on the trait and population sample studied. This implies that metric and non-metric traits share a moderate to high degree of developmental determination. The cause of these correlations may lie in the common effects that growth and development of the soft tissue and functional spaces of the cranium exert on both metric and non-metric traits.     

Selective predation of the pike Esox lucius: comparison of lateral plates and some metric features of the three-spined stickleback Gasterosteus aculeatus

Selective predation of Esox lucius on Gasterosteus aculeatus in a natural assemblage of fish of a stream in Central Poland is described and analysed. The number of lateral plates, the standard length and four size-dependent traits were significantly smaller for sticklebacks from stomach samples than for those from population samples. Thc remaining three metric traits were not significantly different among the samples. The regressions of five metric features (out of seven) on the standard length were significantly different between the sample of caten sticklebacks and that from the free-living population. This supports the supposition that the selectivity of pikc predation with respect to metric traits is not attributable to selection on body size of the prey. Thus, it is reasonable to claim that the sample of caten sticklebacks is selectively taken from the natural population. It justifies the selective predation assumption of some hypotheses of the causes of the pattern of geographic variation in the three-spined stickleback.     

Evaluating sample allocation and effort in detecting population differentiation for discrete and continuously distributed individuals

One of the most pressing issues in spatial genetics concerns sampling. Traditionally, substructure and gene flow are estimated for individuals sampled within discrete populations. Because many species may be continuously distributed across a landscape without discrete boundaries, understanding sampling issues becomes paramount. Given large-scale, geographically broad conservation efforts, researchers are looking for guidance as to the trade-offs between sampling more individuals within a population versus few individuals scattered across more populations. Here, we conducted simulations that address these issues. We first established two archetypical patterns of dispersion: (1) individuals within discrete populations, and (2) continuously distributed individuals with limited dispersal. We used genotypes generated from a spatially-explicit, individual-based program and simulated genetic structure in individuals from nine different population sizes across a landscape that either had barriers to movement (defining discrete populations) or isolation-by-distance patterns (defining continuously distributed individuals). Then, given each pattern of dispersion, we allocated samples across four different sampling strategies for each of the nine population sizes in various configurations for sampling more individuals within a population versus fewer individuals scattered across more populations. We assessed the population genetic substructure with both the population-based metric, F _ST, and an individual-based metric, D _PS regardless of the true pattern of dispersion to allow us to better understand the effect of incorrectly matching the metric and the distribution (e.g., F _ST with continuously distributed individuals, and vice versa). We show that sampling many subpopulations (or sampling areas), thus sampling fewer individuals per subpopulation, overestimates measures of population subdivision with the population-based metric for both patterns of dispersion. In contrast, using the individual-based metric gives the opposite results: sampling too few subpopulations, and many individuals per subpopulation, produces an underestimate of the strength of isolation-by-distance. By comparing all results, we were able to suggest a strong predictive model of a chosen genetic structure metric for elucidating the sampling design trade-offs given each pattern of dispersion and configuration on the landscape.     

Convergence of the age structure: Applications of the projective metric

This paper states necessary and sufficient conditions for the convergence of the age structure (in a discrete time, one-sex model of population growth); it also contains a new and simple proof of the weak ergodic theorem of stable population theory. The main tool used to attain these results is Hilbert's notion of the projective metric. This metric provides a way of defining the distance between positive vectors in $\text{R}$ⁿ which has two important features: First, the distance between any two positive vectors depends only on the rays on which the vectors lie; and, second, positive matrices act as contractions in this metric.     

Variational principles in evolution

For a one-locus selection model, Svirezhev introduced an integral variational principle by defining a Lagrangian which remained stationary on the trajectory followed by the population undergoing selection. It is shown here (i) that this principle can be extended to multiple loci in some simple cases and (ii) that the Lagrangian is defined by a straightforward generalization of the one-locus case, but (iii) that in two-locus or more general models there is no straightforward extension of this principle if linkage and epistasis are present. The population trajectories can be constructed as trajectories of steepest ascent in a Riemannian metric space. A general method is formulated to find the metric tensor and the surface in the metric space on which the trajectories, which characterize the variations in the gene structure of the population, lie. The local optimality principle holds good in such a space. In the special case when all possible linkage disequilibria are zero, the phase point of then-locus genetic system moves on the surface of the product space ofn higher dimensional unit spheres in a certain Riemannian metric space of gene frequencies so that the rate of change of mean fitness is maximum along the trajectory. In the two-locus case the corresponding surface is a hyper-torus.     

Population dynamics in river networks: analysis of steady states

Journal of Mathematical Biology - We study the population dynamics of an aquatic species in a river network. The habitat is viewed as a binary tree-like metric graph with the population density...     

Deciduous dentition of a Late Archaic population of Ohio

I describe the developmental, metric, morphologic, and pathologic features of deciduous dentition in a terminal Late Archaic (c. 3000 B.P.) Native American population in Ohio. Development of deciduous dentition in this Late Archaic population is stable with little sequence variation. The pattern of development (ldc, ldp3, ldp4) cannot be shown to be different from a modern Euro-American sample. There is an indication, however, that the permanent first molar in the Late Archaic population developed somewhat more rapidly with respect to the deciduous teeth than in the Euro-American sample. Metric and morphologic features of deciduous dentition in the Late Archaic population appear typical for a population of northeast Asian descent. In general, these metric and morphologic features are shown to be useful in distinguishing among populations of differing ancestries. Developmental and acquired pathologic conditions of deciduous dentition are rare or absent in the Late Archaic population. Absence of linear enamel hypoplasia indicates sufficient access to basic resources for the younger children of this population, and the low frequency of caries reflects the relatively cariogenic-free nature of the diet of these hunter-gatherers.     

Transferable Measurements of Heredity in Models of the Origins of Life

We propose a metric which can be used to compute the amount of heritable variation enabled by a given dynamical system. A distribution of selection pressures is used such that each pressure selects a particular fixed point via competitive exclusion in order to determine the corresponding distribution of potential fixed points in the population dynamics. This metric accurately detects the number of species present in artificially prepared test systems, and furthermore can correctly determine the number of heritable sets in clustered transition matrix models in which there are no clearly defined genomes. Finally, we apply our metric to the GARD model and show that it accurately reproduces prior measurements of the model’s heritability.     

Needles in the Haystack: Identifying Individuals Present in Pooled Genomic Data

Recent publications have described and applied a novel metric that quantifies the genetic distance of an individual with respect to two population samples, and have suggested that the metric makes it possible to infer the presence of an individual of known genotype in a sample for which only the marginal allele frequencies are known. However, the assumptions, limitations, and utility of this metric remained incompletely characterized. Here we present empirical tests of the method using publicly accessible genotypes, as well as analytical investigations of the method''s strengths and limitations. The results reveal that the null distribution is sensitive to the underlying assumptions, making it difficult to accurately calibrate thresholds for classifying an individual as a member of the population samples. As a result, the false-positive rates obtained in practice are considerably higher than previously believed. However, despite the metric''s inadequacies for identifying the presence of an individual in a sample, our results suggest potential avenues for future research on tuning this method to problems of ancestry inference or disease prediction. By revealing both the strengths and limitations of the proposed method, we hope to elucidate situations in which this distance metric may be used in an appropriate manner. We also discuss the implications of our findings in forensics applications and in the protection of GWAS participant privacy.     

Dental perspectives on the population history of Southeast Asia

This article uses metric and nonmetric dental data to test the "two-layer" or immigration hypothesis whereby Southeast Asia was initially occupied by an "Australo-Melanesian" population that later underwent substantial genetic admixture with East Asian immigrants associated with the spread of agriculture from the Neolithic period onwards. We examined teeth from 4,002 individuals comprising 42 prehistoric and historic samples from East Asia, Southeast Asia, Australia, and Melanesia. For the odontometric analysis, dental size proportions were compared using factor analysis and Q-mode correlation coefficients, and overall tooth size was also compared between population samples. Nonmetric population affinities were estimated by Smith's distances, using the frequencies of 16 tooth traits. The results of both the metric and nonmetric analyses demonstrate close affinities between recent Australo-Melanesian samples and samples representing early Southeast Asia, such as the Early to Middle Holocene series from Vietnam, Malaysia, and Flores. In contrast, the dental characteristics of most modern Southeast Asians exhibit a mixture of traits associated with East Asians and Australo-Melanesians, suggesting that these populations were genetically influenced by immigrants from East Asia. East Asian metric and/or nonmetric traits are also found in some prehistoric samples from Southeast Asia such as Ban Kao (Thailand), implying that immigration probably began in the early Neolithic. Much clearer influence of East Asian immigration was found in Early Metal Age Vietnamese and Sulawesi samples. Although the results of this study are consistent with the immigration hypothesis, analysis of additional Neolithic samples is needed to determine the exact timing of population dispersals into Southeast Asia.