Geographic variation in cranial morphology of narwhals (Monodon monoceros) from Greenland and the eastern Canadian Arctic

We analyzed variation in nine non-metric and eight metric variables in the skulls of 132 narwhals (Monodon monoceros) from five localities in Greenland (Inglefield Bredning, Melville Bay, Uummannaq, Disko Bay, and Scoresby Sound) and one in the eastern Canadian Arctic (Eclipse Sound). Metric variables were used to compare the combined Disko Bay and Uummannaq samples with the samples from Inglefield Bredning and Scoresby Sound using three different multivariate techniques for each sex. None of the results were significant. Seven of the non-metric variables were independent of age and sex and were used in comparing samples from the six localities. No differences were found among the four localities in West Greenland, but differences were found in two of the non-metric variables between the combined West Greenland sample and the one from Scoresby Sound. A major shortcoming of the analysis based on metric data was the small sample size from several of the areas, which resulted in low statistical power. Genetic as well as environmental factors could explain the differences detected here between narwhals living along the west and the east coasts of Greenland.     

Walnut creek massacre: Identification and analysis

The purpose of this study is to add to our understanding of skeletal material from the American pioneer period. Eight White and two Negro skeletons were washed out of their graves during flood conditions of 1973, but the recovery and subsequent storage of this material permitted commingling, and identification of the individual skeletons had to be undertaken before the material could be analyzed. Variation in age, sex, race, metric, non-metric traits and condition of the bone was considered prior to the analysis of the material. When these methods failed, ultra-violet fluorescence of the material and the matching of individual bones with colour slides taken at the time of the excavation were employed. Identification of all bones for the ten skeletons was impossible. However, on the basis of non-metric trait variation a father and son pairing is tentatively identified. Analysis of this material shows the early pioneer to have been a rather tall and robust individual displaying little bone pathology, but advanced pathology in the dental tissue and alveolar region. Historical records pertinent to this massacre validate the identification of sex, race, and age for these individuals.     

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.     

An examination of the meaning of cranial discrete traits for human skeletal biological studies

Discrete traits are of increasing interest in comparative skeletal biological research. Characteristics justifying their use have been investigated primarily in mice, however. Using 72 discrete variants, 321 human skulls from the Terry Collection of known race, sex and age have been studied. Significant sex and age differences were detected. Inter-trait correlation was found to be at a low but significant overall level. Multivariate comparison with conventional craniometric analysis was undertaken on subdivisions of the sample, and distance based on metric and nonmetric data were concordant. It is concluded, on the basis of these findings and the discontinuous variant frequency distributions, that discrete traits in isolation are not of paramount value to skeletal genetic studies, but may be vital in comparison and conjunction with other types of data in analyzing the population genetics of extinct groups.     

Fluctuating asymmetry and genetic variability in the roe deer (Capreolus capreolus): a test of the developmental stability hypothesis in mammals using neutral molecular markers

Fluctuating asymmetry (FA), used as an indicator of developmental stability, has long been hypothesized to be negatively correlated with genetic variability as a consequence of more variable organisms being better suited to buffer developmental pathways against environmental stress. However, it is still a matter of debate if this is due to metabolic properties of enzymes encoded by certain key loci or rather to overall genomic heterozygosity. Previous analyses suggest that there might be a general difference between homeo- and poikilotherms in that only the latter tend to exhibit the negative correlation predicted by theory. In the present study, we addressed these questions by analysing roe deer (Capreolus capreolus) from five German populations with regard to FA in metric and non-metric skull and mandible traits as well as variability at eight microsatellite loci. Genetic variability was quantified by heterozygosity and mean d2 parameters, and although the latter did not show any relationship with FA, we found for the first time a statistically significant negative correlation of microsatellite heterozygosity and non-metric FA among populations. Because microsatellites are non-coding markers, this may be interpreted as evidence for the role of overall genomic heterozygosity in determining developmental stability. To test if the threshold character of non-metric traits is responsible for the metric vs non-metric difference we also carried out calculations where we treated our metric traits as threshold values. This, however, did not yield significant correlations between FA and genetic variability either.     

Paleogenetics of the late Roman-early Byzantine cemeteries at Sayala,Egyptian Nubia

Out of the five late Roman-early Byzantine cemeteries at Sayala, the three large burial complexes CI-III were found to represent the same population not only on the basis of 76·6% of the metric features already studied, but also of 72·9% of the 48 non-metric features examined in the present paper. The remaining features, which show different frequencies, were most probably related to some social and/or genetic isolation of the three subgroups (“lineages”) of the same basic population.The left-right asymmetry of the frequencies was practically irrelevant; sex differences were however present in one-third of the features observed.Some of the traits showed unusually high frequencies, revealing a high rate of inbreeding within a homogeneous population.To evaluate the relationships among the CI-III people and the neighbouring populations, 22 discrete traits were compared with the same traits studied in 11 Ancient Egyptian samples by Berry, Berry & Ucko (1967) and in 6 contemporary African Negro samples by Rightmire (1972). It was shown that the Sayala CI-III population does not resemble either of these groups. The fourth contemporary Sayala sample from A cemetery was also found to be not related with the CI-III sample on the basis of the same traits. The fifth contemporary Sayala sample from N cemetery was too small to be tested. Moreover, the comparison between the CI-III population and the C-group population of Sayala also revealed the lack of genetic continuity. The isolated position found in the CI-III population of Sayala agrees with the hypothesis that it would represent the Blemmyes, people originating from the Eastern Desert.     

Non-metric morphological divergence in the western house mouse, Mus musculus domesticus, from the Barcelona chromosomal hybrid zone

The effect of hybridization on morphological variation was investigated in 120 western house mice, Mus musculus domesticus , from the hybrid zone between the Barcelona and standard chromosomal races. The incidence of 37 non-metric cranial traits was calculated for standard mice (2 n  = 40) and Barcelona-standard hybrids (2 n  = 27–39). Subsequent analyses were conducted on several karyological subgroups, established by grouping the animals according to either their diploid number or their degree of chromosomal heterozygosity. Results revealed no significant difference by sex, asymmetry, or geographical distance. Significant phenetic divergences were found between the karyotypes studied in relation to several variants. Differences were especially substantial between the standard race and hybrid mice, even with respect to those hybrids with karyotypes close to that of the standard race. Within the hybrids, the maximum divergence corresponded to the 28-chromosome homozygotes, chromosomally close to the Barcelona race, and to the heterozygotes with more than two fusions. Since differences in non-metric trait frequencies are generally considered a measure of genetic divergence, the results suggest the occurrence of a barrier to gene flow in the Barcelona hybrid zone. The decrease of genetic exchange between the chromosomally differentiated mice might be due to reduced fertility in hybrids, associated with chromosomal heterozygosity.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 80 , 313–322.     

Sex differences in the Ilia of a known sex and age sample of fetal and infant Skeletons

Ilia from a known sex, race, and age sample of fetal and infant skeletons from the collections of the Smithsonian Institution were evaluated for six metric and one nonmetric characters. Three indices calculated from the measurements were analyzed. The nonmetric trait was examined for fit with known sex. The three indices failed to show significant sex differences. The nonmetric trait, Auricular Surface Elevation, proved dependable (91% accurate) for the male Fetal and Six Month age groups.     

甘肃泾川化石人类头骨性别鉴定

1984年刘玉林等报道了在甘肃泾川发现的一具晚期智人头骨化石,判定该头骨代表一个女性青年个体。本文检查了顶矢状脊、乳突、耳孔上脊、枕外脊、枕外隆凸、枕骨上项线、枕骨圆枕和肌脊8项非测量性状,及星点间宽、星点至人字点距离、颅宽、耳上颅高、顶矢状弦、颞骨鼓板长和宽7项测量性状,并就7项测量性状与武山头骨进行了对比,认为它更有可能属于男性。     

Population variation in sexual dimorphism in the human innominate

In the adult human innominate, pubis length and sciatic notch width are generally considered to offer the best prospect for reliable sex identification. Population variation in the extent of sexual dimorphism in these features was examined in two temporally distinct European skeletal collections of documented age and sex. (English and Dutch). A complex relationship was found to exist between pubis length and sciatic notch width with body size; these relationships differed both between the sexes and between the groups. Caution is therefore urged in the use of both metric and non-metric standards derived from one population and subsequently applied to other populations of differing origin.     

Personality assessment in snow leopards (Uncia uncia)

Knowledge of individual personality is a useful tool in animal husbandry and can be used effectively to improve welfare. This study assessed personality in snow leopards (Uncia uncia) by examining their reactions to six novel objects and comparing them to personality assessments based on a survey completed by zookeepers. The objectives were to determine whether these methods could detect differences in personality, including age and sex differences, and to assess whether the two methods yielded comparable results. Both keeper assessments and novel object tests identified age, sex, and individual differences in snow leopards. Five dimensions of personality were found based on keepers' ratings: Active/Vigilant, Curious/Playful, Calm/Self-Assured, Timid/Anxious, and Friendly to Humans. The dimension Active/Vigilant was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. Curious/Playful was significantly positively correlated with the number of visits to the object, time spent locomoting, and time spent in exploratory behaviors. However, other dimensions (Calm/Self-Assured, Friendly to Humans, and Timid/Anxious) did not correlate with novel-object test variables and possible explanations for this are discussed. Thus, some of the traits and behaviors were correlated between assessment methods, showing the novel-object test to be useful in assessing an animal's personality should a keeper be unable to, or to support a keeper's assessment.     

The effects of race,sex, and nutrition on craniofacial differentiation in rats. A multivariate analysis

Wistar and Holtzman rats were fed (a) control diet ad libitum (controls); (b) restricted control diet (undernourished); and (c) low-protein diet ad libitum (malnourished), from weaning to 70 days of age. Mahalanobis D² distances between cranial groups were assessed. Besides, differences among traits were assessed by the analysis of variance and Tukey test. The relative influence of each factor yielded a decreasing sequence: protein-calorie malnutrition (PCM)-Protein deficit (PD)-race-sex. However, this sequence differed between races. The significant sexual dimorphism in Wistar controls disappeared because of PCM and PD. Race and sex, race and nutrition, and race, sex, and nutrition interacted. Traits were classified into: (a) specific, (b) nonspecific, and (c) invariable. The specific race traits were alveolar length and foraminal width. The specific nutritional traits were neurocranial and splanchnocranial lengths and heights, alveolar and neurocranial widths, and the neuro-splanchnorcranial index (NSI) and the neurocranial vertico-transversal index (NVTI). There were no specific sexual traits. It was concluded that nutritional factors can modify a taxonomic distance in three different ways: (a) evoking morphological differences among populations of the same racial group, (b) altering differences among racial groups, and (c) modifying the pattern of sexual dimorphism of a population. It is suggested that craniological studies should take into account only the set of specific traits, disregarding both specific traits due to other factors and nonspecific ones.     

The calvarial donor site: an anatomic study in cadavers

In a study of 200 fresh adult cadavers, calvarial thickness was measured at selected points. The variables of age, height, weight, sex, and race were subjected to multiple regression analysis to determine which were significant in the determination of skull thickness. The results indicate that weight, race, and sex are the most important variables. However, the magnitude of the effects of these variables is minimal when considered in relation to clinical requirements. The study provides the clinician with a reasonable basis to obtain preoperative estimation of the thickness of calvarial grafts in the adult at four commonly utilized points.     

Sexually dimorphic pelvic morphology in South African whites and blacks

It is well known that there is metric and morphologic variation in the expression of sexual dimorphism between racial phenotypes and populations. Therefore, the purpose of this research is to assess morphologic sex differences in the pelves of South African whites and blacks. Results will be used to improve the identification of human skeletal remains by producing group specific standards. Morphologic features of both left and right os coxae were studied in a sample of 400 known sex/race individuals from the Pretoria and Dart collections. Bones that were clearly pathologic or visibly deformed were excluded from the study. Data were subjected to SPSS analysis.

Results indicated that overall, pubic bone shape was the easiest to assess and was the most consistently reliable morphological indicator of sex in both sexes and population groups. At 88% average accuracy, the most discriminating traits in whites were pubic bone shape and subpubic concavity form. In blacks, greater sciatic notch form allowed the highest separation, averaging 87.5%, followed by pubic shape at 84.5%. Important findings included the fact that there were significant differences in the accuracy of sex determination from pelvic morphology between both males and females and whites and blacks.

In conclusion, this study provides quantification of individual morphological traits in the os coxae of white and black South Africans that will be of value in forensic and archaeological analyses, especially when dealing with fragmentary remains. It also demonstrates that population differences affect the expression of sexual dimorphism and must be accounted for to develop the most effective methods of analysis.     

Non-metric cranial traits: Sex difference and age dependence

Absence of association with age and/or sex in the case of discrete traits was hypothesized by Berry & Berry (1967). The important implication that skeletal material too fragmentary for sex and age determination may also be used in discrete-trait-studies stimulated us to test this hypothesis for 49 discrete traits in 254 Amsterdam crania of known age and sex. The results were compared with those of other such studies of European skulls. No significant deviation from the hypothesis was found as far as age dependence is concerned while sex difference did occur for some traits. At the same time Corruccini's (1974) conclusion that the hypothesis fails when tested in the Terry collection was found to result largely from the fact that right and left manifestations of lateral traits were treated as being independent. The possibility of including skeletal material too fragmentary for sex and age determination in future discrete-trait-studies is still open for discussion.     

Paternal-age and birth-order effect on the human secondary sex ratio.

Because of conflicting results in previous analyses of possible maternal and paternal effects on the variation in sex ratio at birth, records of United States live births in 1975 were sorted by offspring sex, live birth order (based on maternal parity), parental races, and, unlike prior studies, ungrouped parental ages. Linear regression and logistic analysis showed significant effects of birth order and paternal age on sex ratio in the white race data (1.67 million births; 10,219 different combinations of independent variables). Contrary to previous reported results, the paternal-age effect cannot be ascribed wholly to the high correlation between paternal age and birth order as maternal age, even more highly correlated with birth order, does not account for a significant additional reduction in sex-ratio variation over that accounted for by birth order alone.     

Some variables of the craniofacial complex in a Venezuelan population of negroid ancestry

A total of 226 individuals (101 males and 125 females), from La Sabana, a Venezuelan Negroid isolate, with ages between 8 and 60 years, were studied in order to characterize the population for its craniofacial variables and to study the behavior of these variables in relation to age and sex. The variables studied were grouped in three categories: direct cephalometric variables, which included 6 measurements taken directly on the individuals; indirect cephalometric variables, which included 18 measurements (9 angular and 9 linear), taken on lateral head films; and dental variables, which included 9 measurements taken from dental models. In general the direct variables showed the lowest coefficients of variation (CV), suggesting homogeneity within this sample. They were followed by the dental and the indirect variables, which had the highest CV values. In order to detect age and sex effects on the variables, sex and age group comparisons were performed with Student t tests. A greater proportion of significant differences were found among the direct variables, indicating that age and sex have more influence on this group of variables than upon the other two. Comparisons of our sample from La Sabana, with samples from African Negroid, Caucasoid, and Amerindian population show that La Sabana individuals have a craniofacial pattern basically Negroid, as we expected, although some contribution from Caucasoides and especially Amerindians is also suggested in our data.     

Interspecific relations of African crocidurine shrews (Mammalia: Soricidae) based on multivariate analysis of mandibular data

Eighteen graded non-metric characters and 30 measurements of the mandible and lower dentition were used to investigate the grouping of African species of the genera Crocidura, Suncus and Sylvisorex. Seventy-seven taxa (species, subspecies and synonyms), including four European species, were represented by one to nine mandibles (147 mandibles in all), and the means of four Pleistocene African species were also included. The metric data were subjected to principal component and canonical variate analyses, and the non-metric data to principal component analysis. Grouping was detected by comparing the results of the three analyses. Six groups are recognized within the genus Crocidura , typified by C. fumosa, C. turba, C. russula, C. fuscomurina, C. hirta and C. flavescens. Sylvisorex is divisible into two groups, typified by S. lunaris and S. granti. The African species of Suncus (but not the introduced species, S. murinus ) form a single group, which is linked to the Sylvisorex granti group. Suncus is closely related to, or convergent with, the Crocidura fuscomurina group. The first non-metric principal component, the second metric principal component and the second canonical variate are significantly correlated. It is considered that these together represent a general trend of evolutionary advance. Phylogenetic relations are discussed in the light of this; Crocidura may be diphylefic.     

Patterns and Trends in Accidental Poisoning Deaths: Pennsylvania’s Experience 1979-2014

IntroductionThe purpose of this study was to examine county and state-level accidental poisoning mortality trends in Pennsylvania from 1979 to 2014.MethodsCrude and age-adjusted death rates were formed for age group, race, sex, and county for accidental poisonings (ICD 10 codes X40-X49) from 1979 to 2014 for ages 15+ using the Mortality and Population Data System housed at the University of Pittsburgh. Rate ratios were calculated comparing rates from 1979 to 2014, overall and by sex, age group, and race. Joinpoint regression was used to detect statistically significant changes in trends of age-adjusted mortality rates.ResultsRate ratios for accidental poisoning mortality in Pennsylvania increased more than 14-fold from 1979 to 2014. The largest rate ratios were among 35–44 year olds, females, and White adults. The highest accidental poisoning mortality rates were found in the counties of Southwestern Pennsylvania, those surrounding Philadelphia, and those in Northeast Pennsylvania near Scranton.ConclusionsThe patterns and locations of accidental poisoning mortality by race, sex, and age group provide direction for interventions and policy makers. In particular, this study found the highest rate ratios in PA among females, whites, and the age group 35–44.