Sex and side differences in the minor non-metrical cranial variants

Nonmetric Variants of Anatolian Crania: A Preliminary Study

Analysis of nonmetric cranial variants has been essential for identifying the human population through osteologic analysis and genetic affinities. This study aimed to examine the nonmetric cranial variants to evaluate differences among sex and side correlations in Anatolian dry skulls. This study was carried out on 50 Anatolian adult dry human skulls (22 males, 28 females) with suitable features (nonfractured and/or with necessary features) out of a total of 97 dry skulls. After sex analysis, each skull was photographed from the norma frontalis, lateralis, inferior, and superior. Eleven nonmetrical cranial variants were investigated. The cranial variants and side incidences were analyzed to determine their sex differences and interside correlations. After the classification, traits were marked as "present" or "absent" on the charts. Some variants in female crania were seen more frequently than in males. Most of the variants such as the supraorbital notch, infraorbital and zygomaticofacial foramen, showed high correlations between the right and left sides. Overall, there were no statistically significant sex or side differences found in the Anatolian crania.

Variability in the number of infraorbital foramina in rhesus macaques (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis)

This study aimed to determine the number of infraorbital foramina in monkeys of the Papionini tribe. The authors performed a μCT analysis of the morphology of the infraorbital foramina. A total number of 52 simian skulls belonged to two macaque species: Macaca mulatta and Macaca fascicularis were used in the study. The number of infraorbital foramina was counted macroscopically and with the use of a magnifying glass. Next, the skull representing the most common morphological type was selected and scanned by micro-computed tomography (μCT). The Shapiro-Wilk normality test was used in the study. To compare the differences in the number of infraorbital foramen between species, sex and sides, the Mann-Whitney U test was applied. Three infraorbital foramina were present in most individuals from the test group. The Mann-Whitney test revealed no statistically significant difference between the number of foramina on the right- and left-hand side. Likewise, no statistically significant differences between the numbers of infraorbital foramina across sexes were observed. Volumetric reconstructions revealed the presence of separate infraorbital canals for each infraorbital foramen. Craniofacial innervation in macaques is formed by complex branching patterns of cranial nerves. Variability in the number of infraorbital foramina suggests a variable maxillary innervation pattern in these animals. Based on the analysis of volumetric projections, the presence of two labial branches and a single nasal branch of the infraorbital nerve is suggested. Detailed descriptions are supported by quantitative data and μCT evidence.

The study of hyperostosic variants: significance of hyperostotic variants of human skulls in anthropology

Minor variations in the ossicles, foramina and ridges of the cranium have aroused the curiosity of anatomists for many decades. These non-metric variants help us to study the genetic relationships among ancient populations. Since these traits show considerable frequency differences in different populations, they can be used as anthropological characters in epidemiological studies. These variants indirectly reflect the part of underlying genotype of a given population thus implying their usefulness in biological comparisons of related groups. They can be used for the assessment of the existence of the parental structures within a community or as taxonomic indicators. For anthropological studies, the traits should be genetically determined, vary in frequency between different populations and should not show age, sex, and side dependency. The present study was conducted on hundred dry adult human skulls from Northern India. They were sexed and studied for the presence of hyperostotic traits (double hypoglossal canal, jugular foramen bridging, and paracondylar process). Sexual and side dimorphism was observed. None of the traits had shown statistically significant side and sexual dimorphism. Since the dimorphism is exhibited by none of them, it can be postulated that these traits are predominantly under genetic control and can be effectively used for population studies.

The frequency of metopism in Anatolian populations dated from the Neolithic to the first quarter of the 20th century

Metopism, which is defined as a condition in which the two pieces of the frontal bone fail to merge in early childhood, displays varying degrees of incidence. In this study, the variation of the frequency of metopism across historical periods is investigated on the skulls of 487 adults from 12 different Ancient Anatolian populations dated to various periods of history ranging from the Neolithic to the first quarter of the 20th century. In addition, the study also examines the relationship of metopism to sex and cranial form. It is revealed that the frequency of metopism showed a relative increase across time periods in Anatolia after the Neolithic Period, with the exception of the Cevizcioğlu Ciftliği population. However, no significant relationship was found between metopism and cranial form or sex. It is found that the frequency of metopism in Ancient Anatolia had a distribution range of 3.3-14.9%. This distribution shows that the inhabitants of Anatolia have a heterogeneous genetic make-up due to the geographical situation of Anatolia, which has been open to gene flow both in the past and at present.

Twenty-five thousand-year-old triple burial from Dolní Vĕstonice: an ice-age family?

In 1986 a paleolithic triple burial was discovered near Dolní Vĕstonice (Czech Republic). The occurrence of anatomic variants in all three skeletons gave rise to speculations that the buried individuals may have been closely related. To test this hypothesis the skeletons were submitted to a systematic kinship analysis based on odontologic and other non-metric traits. Statistical tests showed that the coincident occurrence of several rare traits in the individuals is highly unlikely to occur at random. This and further data included in the analysis therefore suggest that the three individuals buried together were genetically related and actually belonged to one family.

Behavior-induced auditory exostoses in imperial Roman society: evidence from coeval urban and rural communities near Rome

Presence and features of auditory exostoses were investigated in two cranial samples of Roman imperial age (1st-3rd century A.D.). The skeletal material comes from the necropolises of Portus (Isola Sacra) and Lucus Feroniae (Via Capenate), two towns along the Tevere River, in close relation with the social and economic life of Rome. Deep-rooted differences between the human communities represented by the skeletal samples (83 and 71 individuals, respectively, in this study) are documented both historically and archaeologically. The results show lack of exostoses in the female sex, a negligible incidence among the males of Lucus Feroniae, but a high frequency in the male sample from Isola Sacra (31.3%). Auditory exostoses are commonly recognised as localized hyperplastic growths of predominantly acquired origin. Features of the exostoses found in the male crania from Isola Sacra (particularly in relation to the age at death of the affected individuals) support this view. Furthermore, several clinical and anthropological studies have pointed out close links between the occurrence of auditory exostoses and prolonged cold water exposure, generally due to the practice of aquatic sports, or to working activities involving water contact or diving. In this perspective, the differences observed between the two Roman populations and between the sexes (in Isola Sacra) appear to result from different social habits: the middle class population of Portus habitually used thermal baths, whereas it is probable that thermae were seldom frequented (if at all) by the Lucus Feroniae population represented in the necropolis (mostly composed by slaves or freedmen farm laborers).(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship between auditory exostoses and cold water: a latitudinal analysis

The frequency of auditory exostoses was examined by latitude. It was found that discrete bony lesions of the external auditory canal were, with very few exceptions, either absent or in very low frequency (less than 3.0%) in 0-30 degrees N and S latitudes and above 45 degrees N. The highest frequencies of auditory exostoses were found in the middle latitudes (30-45 degrees N and S) among populations who exploit either marine or fresh water resources. Clinical and experimental data are discussed, and these data are found to support strongly the hypothesis that there is a causative relationship between the formation of auditory exostoses and exploitation of resources in cold water, particularly through diving. It is therefore suggested that since auditory exostoses are behavioral rather than genetic in etiology, they should not be included in estimates of population distance based on nonmetric variables.