Sex determination of Finnish crania by discriminant function analysis

Using multivariant discriminant function analysis, the sex of 232 Finnish crania of known sex was determined. Eight measurements were used to form two discriminant functions. In 80% of cases the sex determination by means of the discriminant functions was identical with the original information. The applicability of the sex discriminant function of Giles and Elliot ('63) for American white and Negro crania was also tested on the Finnish crania. An accuracy of only 65% was attained.     

Classification and misclassification in sexing the Black femur by discriminant function analysis

Stepwise discriminant function analysis for sex assessment was applied to 130 North American Black femora. The measurements included femoral length and three midshaft dimensions likely to be preserved in archaeologically derived and forensic remains. The method correctly assigned sex for 76.4% of the sample (range 70.8–81.5%). This compares favorably with results achieved with other skeletal parts; it also compares favorably with results using the femur in sexing other racial groups. Among our other conclusions are: (1) a “general size factor” is one of major significance in correct classification and in misclassification of sex, and most misclassified individuals are anomalous for this factor; (2) the inconsistency in the relation between circumference and femoral length, which characterizes the remaining misclassified individuals, suggests that anomalous functional demands of body weight/musculature are at fault, and affect circumference more than length; and (3) discriminant function analysis of the same variables in Whites produced similar results, suggesting that sex overrides race in sex assessment; this was confirmed by cross-validating the predictive accuracy of Black discriminant function coefficients on White data, and vice versa.     

Sex and race differences in finger ridge-count correlations

Correlations between ridge-counts on the ten fingers were compared by race and sex in 11 samples representing Negroes and Caucasians: five from subsaharan Africa, one American Black, three European, one American White and one from India. The samples of European ancestry showed no consistent sex difference in mean correlation, although female American Whites significantly exceeded males. In three of the six Negro samples and in the Parsis of India males showed significantly higher average correlations than females. The pattern of sex and race differences suggests that the sex chromosomes, particularly the Y chromosome, play a role in dermal ridge development.     

A statistical study of the multivariate structure and race-sex differences of American white and Negro fetal skeletons

The techniques of factor analysis and discriminant analysis have been applied to 21 measurements of 115 fetal, American White and Negro skeletons. It was found that the factor patterns of the race-sex groups are similar and that two factors describe approximately 85% of the total variance of the multivariate structure of the skeleton. Discriminant analyses showed that differences between the sexes are more marked than those between the races. A function was obtained by which the sex of fetal skeletons may be classified.     

Assessment of race from the pelvis

Racial assessment of human postcranial skeletal remains has been a major concern for forensic and skeletal anthropologists. Materials (N = 400) of the present study are from the Terry Collection and consist of 100 black and white American pelves of both sex with known age and race. Measurements were taken from the articulated pelves. Results of discriminant function analysis indicate classificatory accuracy may be as high as 88%. Transverse pelvic breadth contributes more to the function than biiliac breadth and antero-posterior height. The females are more easily assessed racially than males. Although a highly reliable classification is produced, the results of the study should be employed with caution, as samples were of questionable nutritional status and of low socioeconomic class.     

Anterior femoral curvature: Its probable basis and utility as a criterion of racial assessment

Stewart ('62) and Walensky ('65) indicated that while the metrical expression of anterior femoral curvature alone will not always differentiate between Whites, American Negroes, and North American Indians, it was very useful as a racial criterion in combination with observed traits such as torsion, pilastry, and cross-sectional shape. Seven additional North American Indian groups reported here, representing both pre-Columbian and post-contact times, upheld the observation that anterior femoral curvature is a useful feature of racial assessment for Negroes, Whites and North American Indians. However, two South American groups studied (Ecuador and Peru) were only slightly more curved than American Negroes, and were less curved than Whites and North American Indians. The metrical expression of anterior femoral curvature therefore is not a useful feature of racial assessment for separating these two South American Indian groups from Whites and American Negroes. Femora of American Negro and White individuals with low ponderal indices were found to be less bowed than the norms for their race; individuals with high ponderal indices were more bowed than the norm for their race. The assumed genetic basis for expression of anterior femoral curvature suggested by Stewart ('62) and Walensky ('65) seems to be a feature of human plastic response to body weight rather than to temporal, clinal, postural or equestrian influences.     

The language skills of New Zealand Polynesian children: From deficiency to diversity

The American Indian and Alaskan Native population has grown rapidly since 1950 because of changes in the racial classification of persons with mixed Indian and non‐Indian descent. These changes have challenged once common expectations that the Indian population was likely to shrink over time through assimilation. However, in regions of the United States where the recent growth of the Indian population has been particularly sharp most married Indians are married to non‐Indians. Fertility rates of women who are part of intermarried couples are lower than fertility rates for Indian women in racially endogamous marriages. The majority of the children of intermarried Indians in high intermarriage regions are labelled with the race of the non‐Indian parent. Intermarriage is likely to substantially reduce the long‐run impact of changes in identification on the future growth of the Indian population. At the same time, in a few states the American Indian population remains ethnically homogenous and shows no signs of imminent amalgamation into the general American population.     

Sex determination from the occipital condyle: discriminant function analysis in an eighteenth and nineteenth century British sample

Fragmentary human remains compromised by different types of inhumation, or physical insults such as explosions, fires, and mutilations may frustrate the use of traditional morphognostic sex determination methods. The basicranium is protected by a large soft tissue mass comprising muscle, tendon, and ligaments. As such, the occipital region may prove useful for sex identification in cases of significantly fragmented remains. The aims of this paper are to (1) evaluate sexual dimorphism in British cranial bases by manually recorded unilateral and bilateral condylar length and width as well as intercondylar measurements and (2) develop discriminant functions for sex determination for this cranial sample. The crania selected for this study are part of the 18th-19th century documented skeletal collection of St. Bride's Church, Fleet Street, London. Adult human skulls (n = 146; male75/female71) were measured to derive statistical functions. Results indicated that expression of sexual dimorphism in the occipital condylar region within the St. Bride's population is demonstrable but low. Crossvalidated classification accuracy ranged between 69.2 and 76.7%, and sex bias ranged from 0.3 to 9.7%. Therefore, the use of discriminant functions derived from occipital condyles, especially in British skeletal populations, should only be considered in cases of fragmented cranial bases when no other morphognostic or morphometric method can be utilized for sex determination.     

Microevolutionary change in Arikara Crania: a multivariate analysis

Measurements of human crania from five archaeological sites were subjected to canonical analysis. The five sites form a temporal sequence, ranging from prehistoric (ca. 1600 A.D.) to late historic (1830 A.D.), and belonging archaeologically to the Coalescent Tradition, which in South Dakota encompasses the historic Arikara Indians and their prehistoric ancestors. One canonical variate in each sex arranges the sites in their appropriate temporal sequence, presumably reflecting systematic microevolutionary change. The hypothesis that the morphological change resulted from gene flow from either White or Mandan Indian sources was tested using a two-group discriminate function. The function is found to effectively discriminate a Mandan sample and prehistoric Arikara, but becomes progressively less effective on the historic Arikara crania. This would suggest that Mandan gene flow into Arikara populations is responsible for the observed temporal variation. A similar analysis using British White crania suggests the possibility of slight White influence, but the effect is minimal compared to Mandan.     

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.     

Notches in the non-epiphyseal ends of the metacarpals and phalanges in children of four South African populations

The incidence of notches in the non-epiphyseal ends of the shafts of the metacarpals and phalanges was determined from radiographs of the left hand of 1,303 Pretoria school-children aged 6 to 11 years. The group included White, Negro, Coloured and Indian children. The notches represent vestiges of supernumerary epiphyses or pseudo-epiphyses. Notching of one or more of the metacarpals or phalanges was found in 88.9% of White children, 77.1% of Negro children, 84.3% of Coloured children and 78.8% of Indian children. Notches were most common in metacarpal I followed in declining order of frequency by metacarpal II, metacarpal V, middle phalanx V and proximal phalanx I. Notches were rare in other sites. The mean number of notches per subject was significantly higher in males than in females in all four population groups. However, the sex differences appear to be due mainly to earlier obliteration of notches in females. The findings in White children suggest that there is no significant relationship between metacarpal and phalangeal notching and skeletal maturation rate. Notches are significantly more common in Pretoria Whites than in relatively poorly nourished Pretoria Negro children. It is concluded that the occurrence of notches is a normal phenomenon accompanying the ossification of the hand skeleton and that notching is related neither to retardation in skeletal development nor to undernutrition.     

New studies of post-Pleistocene human skeletal remains from the Rift Valley,Kenya

Prehistoric human crania from Bromhead's Site, Willey's Kopje, Makalia Burial Site, Nakuru, and other localities in the Eastern Rift Valley of Kenya are reassessed using measurements and a multivariate statistical approach. Materials available for comparison include series of Bushman and Hottentot crania, South and East African Negroes, and Egyptians. Up to 34 cranial measurements taken on these series are utilized to construct three multiple discriminant frameworks, each of which can assign modern individuals to a correct group with considerable accuracy. When the prehistoric crania are classified with the help of these discriminants, results indicate that several of the skulls are best grouped with modern Negroes. This is especially clear in the case of individuals from Bromhead's Site, Willey's Kopje, and Nakuru, and the evidence hardly suggests post-Pleistocene domination of the Rift and surrounding territory by “Mediterranean” Caucasoids, as has been claimed. Recent linguistic and archaeological findings are also reviewed, and these seem to support application of the term Nilotic Negro to the early Rift populations.     

Paternal effects on the human sex ratio at birth: evidence from interracial crosses

The effects of interracial crossing on the human sex ratio at birth were investigated using United States birth-certificate data for 1972-1979. The sex ratio was 1.059 for approximately 14 million singleton infants born to white couples, 1.033 for 2 million born to black couples, and 1.024 for 64,000 born to American Indian couples. Paternal and maternal race influences on the observed racial differences in sex ratio were analyzed using additional data on approximately 97,000 singleton infants born to white-black couples and 60,000 born to white-Indian couples. After adjustment for mother's race, white fathers had significantly more male offspring than did black fathers (ratio of sex ratios [RSR] = 1.027) and Indian fathers (RSR = 1.022). On the other hand, after adjustment for father's race, white mothers did not have more male offspring than did black mothers (RSR = 0.998) or Indian mothers (RSR = 1.009). The paternal-race effect persisted after adjustment for parental ages, education, birth order, and maternal marital status. The study shows that the observed racial differences in the sex ratio at birth are due to the effects of father's race and not the mother's. The study points to paternal determinants of the human sex ratio at fertilization and/or of the prenatal differential sex survival.     

An assessment of sex using the skull of black South Africans by discriminant function analysis

The derivation of discriminant function equations for skeletal elements of South African populations continues to be an area of interest to both forensic anthropologists and skeletal biologists alike. The skull of black South Africans has previously been subjected to discriminant function analysis, using four measurements and two indices; however, no equations were derived to address the issue of sex determination. Recently Franklin, Freedman and Milne [2005. Sexual dimorphism and discriminant function sexing in indigenous South African crania. HOMO J. Comp. Hum. Biol. 55, 213-228] used the crania of black South Africans, in a three-dimensional approach, with eight linear measurements to investigate sex determination. This study, although valuable, requires the use of highly technical and expensive morphometric equipment that renders it less feasible in South Africa. In response to this, our study uses traditional anthropometric measurements and equipment to address the question of sex determination from the crania and mandible of blacks. One hundred and twenty non-pathological skulls were randomly selected from the Raymond Dart Collection of Human Skeletons, equally distributed by sex and belonging to individuals whose age at death ranges between 25 and 70 years. Fourteen cranial and six mandibular measurements were subjected to discriminant function analyses and discriminant function equations were derived for sex determination. Average accuracies ranged between 80% and 85% and were on par with that obtained in previous studies. Our study shows that traditional methods provide average accuracies that are comparable to those obtained using more complex techniques.     

A comparative study of metric and non-metric traits in a series of modern crania

The purpose of this study is to question the utility of non-metric traits as predictors of age, race, and sex by comparing a group of non-metric variables with a group of metric variables. Twelve metric variables and 15 nonmetric variables were scored on 317 crania from the Terry Collection at the U. S. National Museum, and later statistically evaluated with a number of multivariate analysis programs and a stepwise discriminant program. The metric variables were found to be significant sex and race discriminators, where-as the non-metric variables were non-significant. The non-metric variables were found to be better age discriminators than the metric variables, even though neither could be classified as highly significant. It was concluded that non-metric traits by themselves have very little discriminatory value and should be used instead to supplement other osteological measurements and observations.     

Carpal fusions in children of four South African populations

The incidence of carpal fusions was determined from radiographs of both hands of 2,250 Pretoria schoolchildren aged 72 to 191 months. The group included White, Negro, Coloured and Indian subjects. Of the many possible varieties of carpal fusion, only lunato-triquetral fusion and capitate-hamate fusion were encountered. No examples of lunato-triquetral fusion were encountered in children less than ten years of age. In Pretoria Negroes aged 10 to 15 years, the incidence of lunato-triquetral synostosis is 4.57%, while Pretoria Coloureds show an incidence of 1.51%. This type of fusion was not noted in the White or Indian populations. Two examples of capitate-hamate synostosis were encountered in Pretoria Negroes. The available evidence suggests that these two varieties of carpal fusion may be added to the list of discrete traits varying in frequency from population to population and probably reflecting different underlying gene frequencies. No significant sex difference in incidence of lunato-triquetral fusion was noted in the present study. Lunato-triquetral fusion is about twice as commonly bilateral as unilateral in occurrence.     

Use of Volatile Organic Components in Scat to Identify Canid Species

Abstract: Identification of wildlife species from indirect evidence can be an important part of wildlife management, and conventional methods can be expensive or have high error rates. We used chemical characterization of the volatile organic constituents (VOCs) in scat as a method to identify 5 species of North American canids from multiple individuals. We sampled vapors of scats in the headspace over a sample using solid-phase microextraction and determined VOC content using gas chromatography with a flame ionization detector. We used linear discriminant analysis to develop models for differentiating species with bootstrapping to estimate accuracy. Our method correctly classified 82.4% (bootstrapped 95% CI = 68.8–93.8%) of scat samples. Red fox (Vulpes vulpes) scat was most frequently misclassified (25.0% of scats misclassified); red fox was also the most common destination for misclassified samples. Our findings are the first reported identification of animal species using VOCs in vapor emissions from scat and suggest that identification of wildlife species may be plausible through chemical characterization of vapor emissions of scat. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):792–797; 2008)     

Dental Discriminant Sexing of Arikara Skeletons

Abstract

Two discriminant functions based on buccolingual and mesiodistal dental measurements are presented. These formulae aid sex determination of Arikara Indian skeletons recovered from the Northern Plains. Formula verification techniques indicate sex identification accuracy of at least 80%. These formulae are useful when skeletal preservation is poor or as an aid in sexing subadults.     

Multivoxel Patterns in Fusiform Face Area Differentiate Faces by Sex and Race

Although prior research suggests that fusiform gyrus represents the sex and race of faces, it remains unclear whether fusiform face area (FFA)–the portion of fusiform gyrus that is functionally-defined by its preferential response to faces–contains such representations. Here, we used functional magnetic resonance imaging to evaluate whether FFA represents faces by sex and race. Participants were scanned while they categorized the sex and race of unfamiliar Black men, Black women, White men, and White women. Multivariate pattern analysis revealed that multivoxel patterns in FFA–but not other face-selective brain regions, other category-selective brain regions, or early visual cortex–differentiated faces by sex and race. Specifically, patterns of voxel-based responses were more similar between individuals of the same sex than between men and women, and between individuals of the same race than between Black and White individuals. By showing that FFA represents the sex and race of faces, this research contributes to our emerging understanding of how the human brain perceives individuals from two fundamental social categories.