Sex-diagnosis of isolated Os coxae by discriminant functions

After methodical preparatory work on the selection of the metric characters and their technical definition, 16 variables were measured on every right hip bone in our standard series (Weisbach series). The discriminant functions performed on our standard series proved to be very sharply discriminant. The methodical foundation gained from the Weisbach series was applied to a control series (Tyrol series), whose sex had not been determined. The application of the discriminant analyses enabled a complete and plausible sex diagnosis to be made.     

A method for visual determination of sex, using the human hip bone

A new visual method for the determination of sex using the human hip bone (os coxae) is proposed, based on a revision of several previous approaches which scored isolated characters of this bone. The efficacy of the methodology is tested on a sample of 402 adults of known sex and age of French and Portuguese origins. With the simultaneous use of five characters of the hip bone, it is possible to provide a correct sexual diagnosis in 95% of all cases, with an error of 2% and an inability to identify sex in only 3%. The advantage of this new method is a reduction in observer subjectivity, since the evaluation procedure cannot involve any anticipation of the result. In addition, this method of sex determination increases the probability of a correct diagnosis with isolated fragments of the hip bone, provided that a combination of elements of one character is found to be typically male or female.     

DEVELOPMENT, SEXUAL DIMORPHISM, and INDIVIDUAL VARIATION IN THE SKELETON OF THE FINLESS PORPOISE, NEOPHOCAENA PHOCAENOIDES, IN THE COASTAL WATERS OF WESTERN KYUSHU, JAPAN

Development, sexual dimorphism, and individual variation were examined in the skeleton of the finless porpoise in the coastal waters of western Kyushu, Japan. Skulls ceased growing by 4 yr. Postcranial skeletons ceased increasing in size at an age older than 11 yr. The finless porpoise was estimated to attain cranial maturity by 4 yr and physical maturity at 14–23 yr. Sexual dimorphism was not detectable in most of the cranial characters but was detected in more than half of the postcranial characters. Females tended to show larger values of postcranial characters. The shape of the pelvic bone was obviously different between males and females. Thus, a discriminant function was proposed to determine sex using measurements of this bone. Individual variation was greatest in the feeding apparatus such as length of the rostrum, and least in the braincase.     

SEXUAL DIMORPHISM IN SPOTTED DOLPHINS (STENELLA ATTENUATA) IN THE EASTERN TROPICAL PACIFIC OCEAN

We analyzed 4 meristic and 32 morphometric cranial traits of 612 adult specimens of spotted dolphins ( Stenella attenuata ) from the eastern tropical Pacific Ocean for sexual dimorphism. Eleven 5" latitude/longitude blocks with five or more of each sex were assessed with a two-way ANOVA for sex and geographic differences. Interaction between these two factors was found for six measurements, suggesting that the degree of sexual dimorphism varies geographically for a few characters (although in no discernible geographic pattern). Sexual dimorphism was demonstrated for 23 of the 36 characters, with differences ranging from 0.00 to 5.88 percent. Females characteristically had a longer rostrum, while males generally had larger skulls overall. In terms of number of characters, the extent of sexual dimorphism demonstrated for skulls of spotted dolphins goes considerably beyond that shown for any other small delphine. A discriminant function involving a combination of 10 characters enabled us to identify correctly the sex of more than 75 percent of the specimens. A procedure for correcting specimen measurements is outlined that would enable an investigator to combine male and female specimens in geographic variation studies. A term (zwitter) is proposed for use when referring to specimens where measurements have been corrected to take into account differences between the sexes.     

Sex determination using the femur in an ancient Japanese population

Determination of sex from the femur measurements has been attempted in several populations and various studies have demonstrated the importance of population specific standards in the metric assessment of sex. The present study attempts to establish metric standards for sex determination by using femur measurements for ancient Japanese populations. Osteometric data were obtained from 151 adult skeletal remains from Jomon period, Yoshigo human skeletal collection. Eight femur measurements were taken and the data were analyzed by discriminant analysis using SPSS version 10.0. For the univariate discriminant function derived, precision of sex determination was 93% with the condyle breadth. Prediction values showed that sex differentiation could be done by femur measurements with reliability between 66.9 and 100%, with values for males higher than for females. It is suggested that discriminant formulas developed by femur measurements in this study, can be used for sex determination accurately on fragmentary skeletal remains in ancient Japanese populations.     

基于形态特征判定五种鹬类性别的可靠性

快速准确地鉴定两性同型鸟类个体性别在鸟类生态学研究中具有重要意义。本文选择2008年春季迁徙期在崇明东滩停歇的大滨鹬(Calidris tenuirostris)、红腹滨鹬(C.canutus)、红颈滨鹬(C.ruficollis)、尖尾滨鹬(C.acuminata)及翘嘴鹬(Xenus cinereus)5种两性同型的鹬类,用分子生物学方法进行性别鉴定,并基于个体的形态特征(体重、翅长、喙长、头喙长及跗跖长)采用判别分析方法对性别进行判定。结果表明,尖尾滨鹬雄性各形态特征均显著大于雌性,其他4种鹬类则相反。5种鹬类形态特征的性别差异指数在0.5%~25.3%之间,重叠度在29.4%~98.6%之间。5种鹬类判别分析判定性别的准确率在(0.69±0.06)~(0.96±0.01)之间,其中,尖尾滨鹬判别准确率(0.96)最高,翘嘴鹬判别准确率(0.69)最低。形态特征在两性间的差异程度影响性别的判别准确率。另外,两性性比对性别判别的准确率也有影响:性比偏雄性鸟类的雄性判别准确率高于雌性,而性比偏雌性鸟类的雌性判别准确率高于雄性。采用判别分析估测的性比与分子生物学鉴定结果相似,表明判别分析在判定种群的性比方面具有较高的可靠性。     

Sex determination using the femur in an ancient Anatolian population

Determination of sex from the femur measurements has been attempted in several populations. Numerous studies have also demonstrated the importance of creating population specific standards in the metric assessment of sex. The present study attempts to establish metric standards for sex determination by using femur measurements for ancient Anatolian populations. Osteometric data were obtained from skeletal remains of 130 adults (67 males and 63 females) from the Dilkaya medieval collection. Eight femur measurements were taken and the data were analyzed using t-test and discriminant analysis with the help of Statistical Package for the Social Sciences (SPSS). The basic statistics showed that all measurements were sexually dimorphic. For the univariate discriminant function derived, precision of sex determination was 86.5 % with the condyle breadth. Our prediction values showed that sex differentiation can be done by femur measurements with reliability between 76 % and 88.5 %, with values for female slightly higher than for males. It is suggested that discriminant formulas developed by combinations of femur measurements in this study can be used for sex determination accurately on fragmentary skeletal remains in ancient Anatolian populations.     

中国汉族成人髌骨性别判别初步研究

对256副中国汉族成人左右侧髌骨分别观测,显示各项指标测量值的平均值都是男性大于女性,并具有显著性差异;各指标以髌骨体积判别性别效果最好,单项判别率达94％以上;运用Fisher线性两类判别分析、逐步判别分析方法得出多项指标判别性别的公式,判别率最高达96.1％。本研究还设计了髌骨体积及髌骨内外关节面高指标的测量方法。本研究为髌骨性别判别提供了简单、实用、科学、判别率较高的新方法。     

Sexual dimorphism in human skulls. A comparison of sexual dimorphism in different populations

Application and comparison of sex discriminant functions in different populations led to the conclusion that a certain combination and weighting of a few sex dimorphism variables (in this study we only used craniometric variables) can give a good discrimination between male and female individuals, independent of the racial group to which this function is applied. In our study, the sex-discriminatory power of five discriminant functions which were based on different ordination and selection procedures (e.g. professional knowledge, stepwise discriminant analysis, literature) of the cranial variables is compared. These discriminant functions were applied to three different data sets, the first being skull measurements from an Amsterdam series (Europids), the second skull measurements of a Zulu series (Negrids) and the third skull measurements of a Japan series (Mongolids). Our decision as to whether a function is a good or less good sex-discriminating function is determined by the Dt values (these values give an idea about the discriminatory value of the discriminant function when applied to a new test sample), the number of variables necessary to obtain this Dt and the location of the sectioning point (i.e. comparison between the estimation of the sectioning point and the ”real” sectioning point). These discriminant functions were compared withGiles Elliot's (1962, 1963) “race-independent” sex function.     

上肢长骨的性别判别分析研究

本文对100例(男女各50)国人上肢骨进行了36项测量。统计结果显示所有测量项目均值男性都大于女性并具有显著性的差异。本研究表明可以采用单一指标对破损严重的肢骨进行性别鉴定。36个测量项目中有23项单一指标性别判别率达75％以上,其中9项在80％以上。本文采用Fisher判别分析法建立了56项单一肢骨性别判别函数,判别率为80％—87％。为进一步提高判别效果,采用逐步判别分析法建立了四项逐步性别判别函数,判别率达90％以上。     

下肢长骨的性别判别分析研究

本文对在长春地区收集的下肢骨进行了37项线性测量,统计分析显示,所有项目性别差异显著,采用单项指标性别鉴定可以获得较好的效果,其中一些肢骨两端项目性别鉴定价值优于长度项目,本文采用Fisher判别分析方法和逐步判别分析方法建立了多项下肢骨性别判函数,可用于鉴定国人下肢骨性别,判别率可最高达96.3%。     

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.     

Determination of sex from the hyoid bone

This article explores size differences related to sex in the hyoid bones from the Robert J. Terry Anatomical Collection. A series of measurements were taken from 398 hyoids, both fused and unfused. The inclusion of unfused hyoids in the study provides the opportunity to investigate previously unknown size differences between sexes as well as to determine their utility in determining sex. Two‐way ANOVA was used to explore differences in hyoid size as related to ancestry and sex. Discriminant function analysis was employed to test the ability of the hyoids to be classified by sex. Six discriminant function equations ranging in accuracy from 82% to 85% are provided, each of which is more accurate than many of the discriminant functions developed in past hyoid research, are simple to use, and can be used to estimate the sex of a hyoid regardless of its state of fusion. In addition to providing further information about the morphological form of the hyoid, these analyses provide a method that can be easily employed to assess sex of the individual from the hyoid bone. Am J Phys Anthropol 143:279–284, 2010. © 2010 Wiley‐Liss, Inc.     

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.     

Sex determination using the scapula in New Kingdom skeletons from Tell El-Amarna

Both forensic and archaeological sciences use metric analysis of human skeletal remains for sex estimation of unknown individuals. Thomas Dwight first reported the utility of scapula metrics for sex estimation in 1894, and subsequent years have produced several techniques for sex estimation using scapula metrics. Levels of sexual dimorphism vary across time and space, making these methods not universally applicable. Novel discriminant functions for unique populations are thus necessary. The present study establishes metric standards for sex estimation for a New Kingdom Egyptian skeletal sample from Tell El-Amarna using scapular measurements. The sample for this research consists of 27 individuals (14 males; 13 females) whose sex estimate based on pelvic morphology is unambiguous. The five measurements showing the highest degree of sexual dimorphism (p ≤ 0.001) are used in the discriminant functions reported here: maximum length of the scapula, maximum length of the scapular spine, breadth of the infraspinous body, height of the glenoid fossa, and breadth of the glenoid fossa. The overall leave one out, cross-validated accuracy for the five reported discriminant functions ranges from 84.0 to 88.0%; similar to accuracies reported for the femur and humerus. Functions combining multiple variables produce higher accuracies than those based on single measurements. The unique population of Amarna, being comprised of emigrants from throughout Egypt, suggests these discriminant functions will have utility for Amarna period sites across the spatial distances of Egypt, and possibly the temporal range of the New Kingdom as a whole.     

Determination of sex from the tibia

Determination of sex from the tibial shaft as well as the entire bone itself has not been generally investigated by osteologists . This paper is an attempt to fulfill this need. The purpose is to determine sex from both the complete tibia and the shaft at the nutrient foramen level. The sample was obtained from the Terry Collection and included 159 specimens of whites and blacks. The tibial length, and circumference, anteroposterior, and transverse measurements at the nutrient foramen level were analyzed by means of step-wise discriminant function analysis. It was found that the circumference alone could give, on the average, 80% accuracy in determining sex. The addition of other dimensions to the function increased the accuracy by about 4%. Comparisons of this study with those on the femur indicated that sexual dimorphism in the tibia was a result not only of the general growth and musculo-skeletal activity, but also of the genetic structure of the population, i.e., racial variation.     

Sex determination using the scapula in medieval skeletons from East Anatolia

Sex determination from skeletal human remains by discriminant function analysis is one of the methods utilized in the forensic and osteoarcheological sciences. The purpose of the present study is to establish metric standards for sex determination for medieval Anatolian populations using scapular measurements. The database for this research consisted of 93 adult skeletal remains (47 males and 46 females) from the Dilkaya medieval collection. Four measurements were taken: maximum scapular height, maximum scapular breadth, glenoid cavity height, glenoid cavity breadth, and subjected to discriminant function analysis. All measurements demonstrated some degree of sexual dimorphism, with the highest accuracy of sex determination (94.8%) obtained using maximum scapular breadth. Overall accuracies of the functions ranged from 82.9% to 95.0%, with a higher accuracy rate obtained for female skeletons than for males. Population specific discriminant formulas were developed using combinations of measurements, which can be used in ancient Anatolian populations.     

Morphometric sex determination of young Ospreys Pandion haliaetus using discriminant analysis

Capsule Discriminant functions based on morphometric variables provide a reliable method for sex identification of free‐living and hacked young Ospreys.

Aims To describe an easy, accurate and low‐cost method for sex determination of fully grown nestling and fledgling Ospreys Pandion haliaetus based on morphometric measurements.

Methods Four different measurements were taken in 114 birds (40–73 days old) and a DNA analysis, using PCR amplification, was carried out for sex identification. A forward stepwise discriminant analysis was performed to build the best explanatory discriminant models, which were subsequently validated using statistics and external samples.

Results Our best discriminant function retained forearm and tarsus as the best predictor variables and classified 95.1% of the sample correctly, supported also by external cross‐validations with both hacked and free‐living birds. Moreover, a discriminant function with only forearm as predictor showed a similar high correct classification power (93.4%).

Conclusions These discriminant functions can be used as a reliable and immediate method for sex determination of young Ospreys since they showed high discriminant accuracy, close to that of molecular procedures, and were supported by external cross‐validations, both for free‐living and hacked birds. Thus, these morphometric measurements should be considered as standard tools for future scientific studies and management of Osprey populations     

Sexual dimorphism in the tooth-crown diameters of the deciduous teeth

Mesiodistal and buccolingual crown dimensions of the right deciduous teeth of 133 white children were analyzed for information on sexual dimorphism and sex discrimination using discriminant analysis. Even though consistent differences were found for only 15 out of 20 paired measurements, five of them significant at p = 0.05 or better, discriminant analysis showed the possibility of correctly sexing up to 75% of the juvenile sample, using a maximum of seven deciduous teeth.     

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.