scholarly journals Sex Determination Using Inion-Opistocranium-Asterion (IOA) Triangle in Nigerians’ Skulls

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
C. N. Orish ◽  
B. C. Didia ◽  
H. B. Fawehinmi

Background. Determination of sex is an important concern to the forensic anthropologists as it is critical for individual identification. This study has investigated the existence of sexual dimorphism in the dimensions and the area of the IOA triangle. Methods. A total of 100 adult dry skulls, (78 males; 22 females) from departments of anatomy in Nigerian universities were used for this study. Automatic digital calliper was used for the measurement. Coefficient of variation, correlation, linear regression, percentiles, and sexual dimorphism ratio were computed from the IOA triangle measurements. The IOA triangle area was compared between sexes. Results. The male parameters were significantly (P<0.05) higher than female parameters. The left opistocranium-asterion length was 71.09±0.56 and 61.68±3.35 mm and the right opistocranium-asterion length was 69.73±0.49 and 60.92±2.10 mm for male and female, respectively. A total area of IOA triangle of 1938.88 mm2 and 1305.68 mm2 for male and female, respectively, was calculated. The left IOA indices were 46.42% and 37.40% in males and females, respectively, while the right IOA indices for males and females were 47.19% and 38.87%, respectively. Conclusion. The anthropometry of inion-opistocranium-asterion IOA triangle can be a guide in gender determination of unknown individuals.

2018 ◽  
Vol 19 ◽  
pp. 1-21
Author(s):  
Oleg V. Kukushkin ◽  
Igor V. Dovgal

The current paper is focused on sexual dimorphism of a giant glass lizard, or sheltopusik, Pseudopus apodus apodus (Pallas, 1775) from its northernmost populations inhabiting the Crimea. In total, 72 P. apodus individuals (45 males and 27 females) were collected at the Kerch Peninsula during 2013–2017. To estimate the variability, 13 morphometric parameters and 18 indices characterizing the head and body proportions were used. It was found that males and females differed significantly by means of almost all parameters, except the body and tail sizes. Besides that, the differences by 10 ratios characterizing head proportions were revealed as well. However, a reliable determination of the lizard sex using linear sizes and/or ratios values seems to be impossible because of the strong overlap of the variability ranges in both sexes. At the same time, the use of the canonical discriminant analysis by the complex of morphometric parameters and by ratios has shown that the males and females in both datasets are classified correctly basing on the sex with an accuracy approximating 100%. The differences in the allometric growth of males and females partially define the sexual dimorphism of P. apodus on head size and shape. A sex-related differences in the development of at least one pair of parameters (head and snout lengths) were clearly evident, since isometry was established for males, while allometry ‒ for females. Moreover, the systems of correlation between the body and head parts differ in both sexes. Thus, male characterisitics correlate significanly, while the female ones were less toughly connected, and some pairs of parameters did not correlate at all.


1996 ◽  
Vol 19 (2) ◽  
pp. 254-255
Author(s):  
Michael T. Ghiselin

AbstractIn Darwinian terminology, “sexual selection” refers to purely reproductive competition and is conceptually distinct from natural selection as it affects reproduction generally. As natural selection may favor the evolution of sexual dimorphism by virtue of the division of labor between males and females, this possibility needs to be taken very seriously.


1976 ◽  
Vol 4 (2) ◽  
pp. 289-296 ◽  
Author(s):  
Bem. P. Allen

Research involving race as a criterion for various social choices indicates that race may rival attractiveness for the determination of dating choices. This possibility was explored in two experiments involving “desirability for a date” ratings of black and white stimulus persons who varied in attractiveness. Experiment 1 results indicated that white male and female subjects gave appreciable weight to race and attractiveness, but females gave race more weight than attractiveness, while attractiveness was given more weight than race by males. The interaction between race and attractiveness had approximately the same form for males and females: attractive black stimulus persons were lumped together with unattractive stimulus persons.Female subjects in Experiment 2, who were informed about an opportunity to date a stimulus person of their choice before seeing slides of stimulus persons, tended to discount attractiveness as a criterion for choices. None of these subjects were willing to accept an actual date. It was noted that race may be a stronger rival to attractiveness relative to the more abstract factors with which attractiveness has been compared, because race, like attractiveness, is highly concrete and visible.


Author(s):  
E. I. Edibamode ◽  
K. Mordi ◽  
L. K. David ◽  
A. M. Eghoi

Background. External ear measurement is of utmost importance in reconstructive surgeries. Objectives. The present study is aimed at ascertaining sexual dimorphism in external ear anthropometry and ear lobe attachments among adults Ijaws in Bayelsa, Nigeria. Methods. A total of 112 adults within the age range of 18-50 yrs, who met the inclusion criteria, were involved in the study. Four linear dimensions of the ear, which are ear length (EL), ear width (EW), lobular length (LL) and lobular width (LW), were measured for both genders. The lobular attachment for both ears for males and females were also examined and results recorded. These data were subjected to Student t-test, Chi-square test, and Pearson’s correlation using SPSS version 20.0. Results. The mean values for EL, EW, LL, and LW for the left auricle in the males and females were 58.14±0.60, 27.41±0.37, 14.47±0.27, 13.50±0.34 and 57.90±0.16, 27.45±0.65, 15.41±0.31, 13.43±0.38 respectively. However, for the right auricle in the males and females, the values were 58.40±0.45, 28.21±0.68, 14.32±0.31, 13.04±0.32, and 56.66±1.10, 27.51±0.65, 15.58±0.29, 13.28±0.34 respectively. The left and right lobular length were the only parameters that proved statistical significance (p<0.05) in females compare to males. Pearson’s correlations between right and left sides for each of the parameters were positive and significant. Chi-square analysis revealed no significant relationship (p>0.05) between earlobe attachments and gender. Conclusions. Sexual dimorphism was thus established in the Ijaw population as regards lobular length dimensions. It is believed that the results of this study would be very useful for ear morphology and reconstructive surgeries.


2005 ◽  
Vol 84 (2) ◽  
pp. 160-165 ◽  
Author(s):  
N.S. Treister ◽  
S.M. Richards ◽  
M.J. Lombardi ◽  
P. Rowley ◽  
R.V. Jensen ◽  
...  

Sex-related differences exist in the structure and function of the major glands in a variety of species. Moreover, many of these variations appear to be unique to each tissue. We hypothesized that this sexual dimorphism is due, at least in part, to gland-specific differences in gene expression between males and females. Glands were collected from male and female BALB/c mice (n = 5/sex/experiment), and total RNA was isolated. Samples were analyzed for differentially expressed mRNAs with CodeLink microarrays, and data were evaluated by GeneSifter. Our results demonstrate that significant (P < 0.05) sex-related differences exist in the expression of numerous genes in the major salivary glands, and many of these differences were tissue-specific. These findings support our hypothesis that sex-related differences in the salivary glands are due, at least in part, to tissue-specific variations in gene expression.


2012 ◽  
Vol 4 (3) ◽  
pp. 665-667 ◽  
Author(s):  
Trishna Dutta ◽  
Sandeep Sharma ◽  
Jesús E. Maldonado ◽  
Thomas C. Wood ◽  
John Seidensticker

2005 ◽  
Vol 288 (4) ◽  
pp. H2006-H2013 ◽  
Author(s):  
Virginia H. Huxley ◽  
JianJie Wang ◽  
Stevan P. Whitt

Gender influences volume regulation via several mechanisms; whether these include microvascular exchange, especially in the heart, is not known. In response to adenosine (Ado), permeability ( Ps) to protein of coronary arterioles of female pigs decreases acutely. Whether Ado induces similar Ps changes in arterioles from males or whether equivalent responses occur in coronary venules of either sex has not been determined. Hypotheses that 1) basal Ps properties and 2) Ps responses to vasoactive stimuli are sex independent were evaluated from measures of Ps to two hydrophilic proteins, α-lactalbumin and porcine serum albumin (PSA), in arterioles and venules isolated from hearts of adult male and female pigs. Consistent with hypothesis 1, basal Ps values of both microvessel types were independent of sex. Contrary to hypothesis 2, Ps responses to Ado varied with sex, protein, and vessel type. Confirming earlier studies, Ado induced a ∼20% decrease in Ps to both proteins in coronary arterioles from females. In arterioles from males, Ado did not change Ps for α-lactalbumin ([Formula: see text], 3 ± 13%), whereas Ps for PSA ([Formula: see text]) decreased by 27 ± 8% ( P < 0.005). In venules from females, Ado elevated [Formula: see text] by 44 ± 20% ( P < 0.05), whereas in those from males, Ado reduced [Formula: see text] by 24 ± 5% ( P < 0.05). The variety of outcomes is consistent with transvascular protein and protein-carried solute flux being regulated by multiple sex-dependent mechanisms in the heart and provides evidence of differences in exchange homeostasis of males and females in health and, likely, disease.


2020 ◽  
pp. jeb.235697
Author(s):  
Michael L. Logan ◽  
Lauren K. Neel ◽  
Daniel J. Nicholson ◽  
Andrew J. Stokes ◽  
Christina L. Miller ◽  
...  

If fitness optima for a given trait differ between males and females in a population, sexual dimorphism may evolve. Sex-biased trait variation may affect patterns of habitat use, and if the microhabitats used by each sex have dissimilar microclimates, this can drive sex-specific selection on thermal physiology. Nevertheless, tests of differences between the sexes in thermal physiology are uncommon, and studies linking these differences to microhabitat use or behavior are even rarer. We examined microhabitat use and thermal physiology in two ectothermic congeners that are ecologically similar but differ in their degree of sexual size dimorphism. Brown anoles (Anolis sagrei) exhibit male-biased sexual size dimorphism and live in thermally heterogeneous habitats, whereas slender anoles (Anolis apletophallus) are sexually monomorphic in body size and live in thermally homogeneous habitats. We hypothesized that differences in habitat use between the sexes would drive sexual divergence in thermal physiology in brown anoles, but not slender anoles, because male and female brown anoles may be exposed to divergent microclimates. We found that male and female brown anoles, but not slender anoles, used perches with different thermal characteristics and were sexually dimorphic in thermal tolerance traits. However, field-active body temperatures and behavior in a laboratory thermal arena did not differ between females and males in either species. Our results suggest that sexual dimorphism in thermal physiology can arise from phenotypic plasticity or sex-specific selection on traits that are linked to thermal tolerance, rather than from direct effects of thermal environments experienced by males and females.


2016 ◽  
Vol 60 (1) ◽  
Author(s):  
Maciej Mularczyk ◽  
Angelika Ziętek-Czeszak ◽  
Zbigniew Ziętek

Introduction: Studies on many populations have shown that the length of the second finger (2D) compared to the fourth (4D), expressed as the finger length ratio (2D:4D), might be characteristic for sexual dimorphism. It was also found that the values of 2D:4D differ significantly between examined populations. It is thought that the value of 2D:4D is determined in early foetal life under the influence of genetic factors and the strong influence of sex hormones. It has been proven that the values of 2D:4D are related to, for instance, sexual orientation, and artistic and sporting ability. Recently, increasing interest in the clinical significance of finger length ratio in the diagnosis of somatic and mental disorders has been observed. For example, it was found that values of 2D:4D in individuals suffering from congenital adrenal hyperplasia or autism were significantly lower compared to healthy subjects. The aim of the study was to determine sexual dimorphism in finger length ratio among representatives of the Polish population.Materials and methods: The study group comprised 115 people (57 females and 58 males). Anthropometric measurements were taken from the second and fourth finger of the right and left hands – from the point of dactylion (da) to pseudophalangion (pph) using analogue callipers. We calculated the significance of differences in 2D:4D between males and females separately for the right and left hands.Results: In both hands mean 2D:4D values were lower in males than in females. The difference in the right hand reached the statistical significance level with p < 0.05.Conclusions: Among the subjects from the examined population the 2D:4D ratio shows trends characteristic for sexual dimorphism.


Author(s):  
Kamal Singh ◽  
Aarti Rohilla

Background: Sexing of human skeleton is highly contested subject and is usually done by using morphological and metrical traits of big intact bones like skull, mandible, pelvis and long bones etc.1 The stapes remains well protected by being housed in the middle ear, even in the mutilated bodies.Methods: The morphometric study of the 120 human stapes bones from 60 unidentified cadavers was aimed to know the presence of sexual dimorphism.Results: The weight and measurements of footplate could be a good criterion for determining percentage accuracy as male and female respectively and could be used as a potential tool for determination of sex.Conclusions: The study of normal dimensions and indices of stapes will provide insight to the forensic experts for deciding the sex of an individual in the disputed cases. Our findings are the results for guidance and future manipulation in the forensic and legal medicine.


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