Genetic sexing to determine the optimal discriminant functions for the analysis of archaeological remains from El Hierro (Canary Islands)

A correct sex assignment of a given bone or bone fragment is of paramount importance for the archaeologist, anthropologist and in forensic medicine. Discriminant functions, combining several anthropometric measurements obtained from individuals with known sex are useful tools for this purpose, but it is essential to know exactly the sex from which the measures are obtained. This is an easy task in modern populations, but it is problematic in ancient ones, since even when the entire skeleton is available, diagnosis of sex is not 100% accurate. Sexing by genetic methods by amplifying the first intron of the amelogenin gene constitutes a much more accurate method for sexing bones and may be the gold standard for further elaboration of discriminant functions which may serve for sexing new bones dug up in future excavations. With this aim we have genetically sexed 52 (out of 59) tibiae belonging to the prehispanic population of El Hierro, in the Canary Islands, identifying 18 women and 34 men, and then, performed discriminant functions combining several anthropometric variables. These functions show a high accuracy in sex diagnosis (94.2%; area under ROC curve = 0.954 with the best of the functions), so that they allow correct sexing of tibiae or tibiae fragments (only proximal third, distal third or midshaft). Thus, genetic sexing obviates the problem of finding an accurate gold standard for the elaboration of discriminant functions for ancient bones. This method could be applied to other populations of different antiquity and different ethnicity.     

Estimating the Age and Sex of Caribou from Mandibular Measurements

Formulae for estimating the age and sex of caribou are derived from measurements taken from a control sample of caribou mandibles collected by the Canadian Wildlife Service. A robust linear relationship was found to exist between first molar crown height and age, while male and female mandibular measurements are statistically distinguishable on either side of a linear regression line. The application of these formulae to three 19th century archaeological assemblages from the western Canadian Arctic indicates their usefulness in estimating the age and sex of fossil populations, although some problems due to geographical variability remain. Tentative results indicate that traditional western Arctic Inuit were unable to exert strong control over the age and sex of the caribou they killed, perhaps because of the use of large-scale communal hunting techniques. This situation seems to have changed radically with the introduction of firearms in the 1870s.     

Mandibular ramus posterior flexure: a sex indicator in Homo sapiens fossil hominids?

Accurate determination of sex in skeletal human samples is very important in anthropological and demographic studies. Recently, Loth and Henneberg have suggested that a new osteological criterion on the mandible, the mandibular ramus posterior flexure (MRPF) had a high sex discriminating effectiveness. A preliminary test applied to a few hominid mandibles )including Australopithecines, Homo erectus, Neanderthals and Upper palaeolithic hominids) apparently confirmed the high reliability of the MRPF as a sex indicator ‘over time and through palaeospecies’. As the pelvis is commonly considered as providing the most significant criteria that allows the establishment of skeletal sexual dimorphism of adults, the present paper evaluates this mandibular feature on a few additional palaeolithic hominids (i.e. Neanderthals and Early Modern Humans) for whom a gender estimation was known based upon the pelvis. This analysis was conducted on the original material and its results appear in contradiction with those of the previous studies made by Loth and Henneberg. A reconsideration of the visual assessment of MRPF as a sex indicator in Homo sapiens fossil hominids is therefore suggested. Copyright © 2000 John Wiley & Sons, Ltd.     

Paleodietary analysis of the prehistoric population of the Canary Islands inferred from stable isotopes (carbon,nitrogen and hydrogen) in bone collagen

Nitrogen and carbon isotope compositions were measured in the bone collagen from a total of 86 prehispanic samples of the Canary Islands, and hydrogen in 70, all of them with enough amount of bone collagen, and adequate N and C content. These samples belong to prehistoric population of El Hierro (n = 27), Tenerife (n = 18), and Gran Canaria (n = 41). Isotope compositions were also obtained for prehistoric and modern food resources that were likely consumed by these people. Marked differences were observed among the three islands regarding the three isotopes analyzed: the δ¹⁵N values were highest among the population of Gran Canaria (10.8‰ ± 0.9‰), who also showed the highest δD values (7 ± 8‰). The population of El Hierro showed the highest δ¹³C values (−18.6‰ ± 0.7‰). These data suggest a high consumption of marine products by the population from El Hierro, and also an important consumption of terrestrial meat or marine, piscivore fish, by the population from Gran Canaria, together with domesticated C₃ plants (barley and/or wheat), fruits of Ficus carica and other wild species, and goat products. Additionally, marked differences were observed between men and women, which suggest that women consumed a more vegetal-based diet, a finding which is in agreement with the higher proportion of teeth with carious lesions among women.     

Ectopic Lower Third Permanent Molar within the Mandibular Condyle: An Archaeological Example

Migration of mandibular third molars to abnormal anatomic locations is not unknown. Examples reported in the clinical literature are mainly in the ascending ramus of the mandible and the neck of the mandibular condyle, and only four cases have hitherto been reported actually within the mandibular condyle. This case reports on an ectopic lower third molar within the right mandibular condyle in a 19th century male skeleton from Wolverhampton, West Midlands, UK. Examples of this nature have not been found to be described in the bioarchaeological literature; therefore, this case study probably represents the first case reported in this field. Copyright © 2011 John Wiley & Sons, Ltd.     

A DNA test for sex identification in cattle confirms osteometric results

It is of vital importance to be able to sex identify cattle remains to understand the strategies and importance of cattle husbandry in an ancient society. This is usually done from osteoarchaeological assemblages and often relies on measurements of metapodials. The breadth measurement of the distal trochlea is considered an easy way to identify the sex. Bones from males appears to be easily distinguishable from female counterparts, although it has been complicated to find an external control for the morphological results. Here we investigate the reliability of these particular morphometrics for sex identifying cattle bones with molecular genetics. We use a sex discriminating single nucleotide polymorphism in the ZFXY gene and we apply it to DNA from the bones. To keep the fragment size short and suitable for ancient DNA we base the test on a SNP. The test confirms the osteological sex identification in all cases were DNA could be retrieved. This molecular method can also be used when no fragments suitable for osteological sex identification can be found or when the measurements are non-conclusive.     

The Retromolar Space: A Morphological Curiosity Observed Amongst the Protohistoric Arikara and Mandan

The retromolar space (RMS), defined in palaeoanthropology as a space posterior to the third molar, between the distal edge of the tooth and the anterior margin of the ascending ramus when the mandible is held in lateral view, has been described as an autapomorphic trait unique to Neanderthals despite its presence in anatomically modern humans. This study examined RMS prevalence in a sample of protohistoric Arikara and Mandan Amerindians to determine what craniofacial morphology is correlated with the RMS. It was hypothesised that the feature would be present in the Amerindians studied and associated with a long cranial length, a large nasal height, midfacial prognathism, a broad mandible, and dental wear. The results indicated that RMSs were present in the Arikara and Mandan and significantly correlated with cranial length, cranial breadth, nasal height, bizygomatic breadth, basion‐nasion length, basion‐nasiospinale, mandible length, gonial angle, bigonial breadth, and dental wear. Thus, RMSs are associated with a dolichocephalic skull, wide cranial and facial breadth, a prognathic face, large nose and a corresponding wide and long mandible with a reduced gonial angle. This suggests that the RMS is the result of these features merging together in the craniofacial complex and should not be considered a Neanderthal autapomorphy. Copyright © 2015 John Wiley & Sons, Ltd.     

Further developments in molecular sex assignment: a blind test of 18th and 19th century human skeletons

The identification of sex in human remains recovered from archaeological locations is important in order to understand the social and biological structure of past societies, and to reconstruct past population demographic events. Sex determination is usually based on morphological traits of the skeletons, with the drawback that most methods do not apply to juveniles and require well preserved remains. In cases where morphological methods cannot be used, or are ambiguous, methods of molecular sexing systems are an alternative. In this methodological study we tested and validated the accuracy and usefulness of a molecular sexing method based on the amelogenin gene using pyrosequencing. We did this in a double blind study of documented 18th and 19th century human remains.     

Osteometric and molecular sexing of cattle metapodia

Sex identification of skeletal remains based on morphology is a common practice in Zooarchaeology. Knowledge of the sex distribution of slaughtered or hunted animals may help in the interpretation of e.g. hunting or breeding strategies. Here we investigate and evaluate several osteometric criteria used to assess sex of cattle (Bos taurus) metapodia using molecular sex identification as a control of the metric data. The bone assemblage used to assess these new criteria derives from the Eketorp ringfort in the southern parts of Öland Island in Sweden. One hundred metapodia were selected for molecular analysis of sex and we were able to genetically identify the sex of 76 of these elements. The combined results of the molecular and osteometric analyses confirm a significant size difference between females and males for several measurements for both metacarpals (Mc) and metatarsals (Mt). Our results show that some measurements are applicable for metapodials. These measurements include the slenderness indices such as the Mennerich’s index 1 and 3, as well as the distal breadth (Bd), the breadth between the articular crests (Bcr), and the maximum breadth of the lateral trochlea (BFdl). We show that they can be used for sexing of both metacarpals and metatarsals. The latter measurements offer an opportunity to study fragmented elements and thus a higher number of elements may be utilized for morphological sexing of archaeological bones. Size comparisons of Mc and Mt may also aid in the separation of bulls and oxen.     

Ancient DNA in archaeological wheat grains: preservation conditions and the study of pre-Hispanic agriculture on the island of Gran Canaria (Spain)

The recovery of ancient DNA from archaeological wheat samples under different preservation conditions was assessed using a number of genetic markers. It was possible to amplify nuclear DNA from desiccated grains but not from charred. The desiccated grain was from a pre-Hispanic grain silo in Gran Canaria and showed excellent DNA preservation, enabling the amplification of the ribosomal DNA markers IGS and ITS, the upstream region of the HMW-glutenin locus and single-locus nuclear microsatellites. Our results demonstrated the presence of both durum and bread wheat in an assemblage of naked grain. We were also able to identify different genotypes in durum wheat and compare these with extant landraces, providing insights into the agrarian practices of the ancient Canarians and the origin of their crops.     

An unreduced dislocated mandible in an Alaskan Eskimo: a case of altruism or adaptation?

Mandibular dislocations are rare in archaeological samples. This paper describes an unreduced dislocated mandible in an adult male skeleton from Point Hope, Alaska. The left mandibular condyle has been displaced anteriorly and two new articulations for the left coronoid process and remnant of the left condyle have formed. The left mandibular body and ramus exhibit severe atrophy, and all of the mandibular teeth have been lost antemortem. A review of historical accounts from the early contact period reveals that the Alaskan Eskimos suffered from a variety of disabilities of the musculoskeletal system. Despite these disabilities, however, many of these individuals were able to function with little or no assistance from other members of their group. The fact that this individual survived to an advanced age in the harsh arctic environment is a testament to the body's remarkable ability to compensate for and survive with physical disabilities. Copyright © 2003 John Wiley & Sons, Ltd.     

The Ba/Sr ratio,carious lesions,and dental calculus among the population buried in the church La Concepción (Tenerife,Canary Islands)

Certain trace elements may accumulate in bone in relation to dietary habits, so some of them are of interest in paleodietary analysis. This is the case with strontium (Sr) and barium (Ba), whose potential value as paleodietary indicators is enhanced by their relatively inert metabolic behaviour. The presence of carious lesions may indicate consumption of sugar and vegetables, whereas the etiology of dental calculus deposition is multifactorial, although some authors consider this as an indicator of protein consumption. Based on these facts we analysed (1) Ba, Sr, and calcium (Ca) content of inner cortical bone obtained from the ramus mandibularis, by atomic absorption spectrophotometry, (2) presence of teeth with carious lesions, and (3) presence of teeth with calculus deposition in 62 mandibles. All samples were obtained from the church La Concepción, an 18th century burial place in Tenerife. Gender was assessed by analysing genetic expression of amelogenin in some cases (14), and by inspection of pelvic bones when available (41 cases). We found (1) Carious lesions in 32 cases, and dental calculus, in 39; no association was observed between sex and presence of dental caries or calculus deposition, nor between the sex and the proportion of carious teeth nor the proportion of teeth with calculus deposition; (2) people buried near the altar (priests and individuals of the highest social class) showed a significantly higher proportion of teeth with dental calculus deposition (χ² = 5.36, p = 0.021); (3) bone Sr and bone Ba were significantly higher than the values observed in a control group of 10 modern omnivorous individuals; the lowest Sr values were observed among people buried near the altar; and (4) the Ba/Sr ratio was directly related with the proportion of teeth with carious lesions. These data suggest that there were differences in dietary pattern among the individuals belonging to different social classes; overall, consumption of vegetables was widespread, as shown by the high proportion of carious lesions, in relation with raised Ba/Sr ratio, whereas consumption of marine products was scarce.     

Assessing the reliability of criteria used to identify mandibles and mandibular teeth in sheep, Ovis, and goats, Capra

Criteria developed to distinguish between the mandibles and mandibular teeth of sheep and goats are evaluated using modern specimens from the collections of the National Museum of Natural History and the Field Museum of Natural History. Certain teeth prove to be quite reliable in this regard (dP3, P3, P4). Other dental elements, however, are not reliable and should not be used in dental based identifications of these closely related species (dP4, M1, and mandibular bones). Overall, the identification of sheep dentition using these criteria is more reliable than it is for goats. However, the generally greater likelihood of incorrect identification of goat teeth and mandibles means that specimens identified as sheep are likely to contain high proportion of misidentified goats. Both the proportion of remains that can only be classified as ‘Ovis-Capra’ and the proportion of incorrectly identified teeth and mandibular bones varies with age, with identifications of younger and older animals less reliable than those of animals in the 1.5–6 year age range. Reliability of identifications increases when more criteria and more elements are used. Identifications based on whole mandibles with complete tooth rows are quite reliable. However, the proportion of specimens likely to be classified as ‘Ovis-Capra’ also increases in whole mandible identifications, especially in goats. Systematic differences in the proportions of indeterminate and incorrect identifications have a significant impact on species-level dentition-based harvest profiles. Recommendations are made for the use of dentition and long bone based harvest profiles in the study of sheep and goat exploitation strategies.     

Stafne's defects in two mandibles from archaeological sites in Croatia

Salivary gland inclusions in the mandible are relatively uncommon in recent as well as archaeological populations. This condition is well known to oral surgeons, but less so to anthropologists, osteologists and skeletal biologists. At present a limited number of reports pertaining to this condition in ancient populations are available in anthropological and palaeopathological literature, although scattered reports of cases in recent populations are found in dental journals. This paper analyses the prevalence of Stafne's bone defect in a large composite Croatian archaeological series (n = 4250 mandibles), and reports on two cases in which computerised tomography was performed, in order to draw the attention of anthropologists, osteologists and skeletal biologists to this condition when faced with differential diagnosis of odontogenic lesions, cysts and neoplasms in the area of the angle of the mandible. Copyright © 2009 John Wiley & Sons, Ltd.     

Accurate sex identification of ancient human remains using DNA shotgun sequencing

Accurate identification of the biological sex of ancient remains is vital for critically testing hypotheses about social structure in prehistoric societies. However, morphological methods are imprecise for juvenile individuals and fragmentary remains, and molecular methods that rely on particular sex-specific marker loci such as the amelogenin gene suffer from allelic dropout and sensitivity to modern contamination. Analyzing shotgun sequencing data from 14 present-day humans of known biological sex and 16 ancient individuals from a time span of 100 to ∼70,000 years ago, we show that even relatively sparse shotgun sequencing (about 100,000 human sequences) can be used to reliably identify chromosomal sex simply by considering the ratio of sequences aligning to the X and Y chromosomes, and highlight two examples where the genetic assignments indicate morphological misassignment. Furthermore, we show that accurate sex identification of highly degraded remains can be performed in the presence of substantial amounts of present-day contamination by utilizing the signature of cytosine deamination, a characteristic feature of ancient DNA.     

Boards and Cords: Discriminating Types of Artificial Cranial Deformation in Prehispanic South Central Andean Populations

For over a century, a number of ambiguous typologies have been employed to distinctly categorise types of artificial cranial deformation. This paper provides a quantitative method, based on multiple dimensions and discriminant function analysis, by which to assign skulls not only into discrete categories: deformed or not, but also by type: annular or tabular. A series of prehispanic, adult, human crania (n = 469) from archaeological sites in Argentina, Bolivia, Chile and Peru represented by both normal and artificially deformed specimens, provide craniometric data for four measurements across the vault: maximum cranial length, breadth and height and the frontal chord. These data are used to develop three indices which in turn are used to compute two discriminant functions. Results are plotted on a territorial map whereby the type of deformity can be determined. When these methods were applied to a comparative cranial sample of nondeformed skulls from South America, 100% of the samples was found to be nondeformed. When these methods were applied to the samples which were subjectively classified a priori by the first author as nondeformed, 81.3% of the samples were found to be nondeformed. This study demonstrates the value of a more objective and quantitative method by which to classify artificial cranial deformation, and thus provides a new approach. Copyright © 2011 John Wiley & Sons, Ltd.     

Mandibular Fracture and Dislocation in a Case Study from the Jewish Cemetery of Lucena (CÓRDOBA), in South Iberian Peninsula (8th–12th ad)

The skeletal remains of an adult female have been exhumed in an 11th century tomb in the mediaeval Jewish cemetery of Ronda Sur, in the city of Lucena (Córdoba, Spain). Examination of the skull and mandible revealed evidences of bilateral condylar fracture and dislocation. Lesions were observed macroscopically and radiology was used as a complementary method of scrutiny, especially in cases of unclear observation. Irregular morphology of the condyles and coronoid processes, shallow glenoid fossa, altered and abnormal joint surfaces anterior to the glenoid fossa, and reduced height of both ascending rami were observed. Ante‐mortem tooth loss, slight wear of occlusal surface and asymmetrical occlusal deposit of dental calculus were found. Radiologically, degenerative changes in the condyles and reparative bone in both coronoid processes have been identified. Dislocation of the condyles and lack of adequate treatment probably led to disruption of masticatory patterns and related structures, such as muscle attachments, articular disc and ligaments. Bilateral remodelled fracture and the altered appearance of the joint structures could probably mean that the individual survived the injury by several years. This type of fracture could be the consequence of direct blow to the mental or submental region that was transmitted in a direction that raised the mandible, causing the condylar head to collide directly with the mandibular fossa. Very few mandibular fractures in ancient skulls have been described in Spain, and this case is the first example found in a Spanish archaeological skeletal assemblage. Copyright © 2011 John Wiley & Sons, Ltd.     

Study of stafne's defects in Late Neolithic,Late Roman,Medieval and Modern skeletal samples from Portugal

Lingual mandibular cortical defects (Stafne's defects) are relatively uncommon in recent as well as past populations, but while this condition is often discussed in clinical reports, they are rarely the subject of anthropological research. In this paper, the prevalence of Stafne's bone defects in skeletal samples from Late Neolithic, Late Roman, Medieval and Modern Portugal is investigated (N = 704 complete mandibles and 111 incomplete mandibles). The aims of this paper are threefold: (1) to present and analyse for the first time in Portuguese osteological record prevalence data on Stafne's bone defect, (2) to analyse variations in defect prevalence between skeletal samples from a wide temporal array and (3) to verify if more tenuous lesions in which resorption of the lingual cortex was not yet extensive had the classic radiographic appearance described by Stafne in order to validate the hypothesis that lesions are present clinically in many more cases than published figures indicate. In all cases, differential diagnosis against other conditions that mimic Stafne's defects, namely odontogenic lesions, cysts and neoplasms, was done. In all samples, the evidence of Stafne's defect occurred in 12 individuals (1.7%), and males (2.84%) were more frequently affected than females (0.61%). When incomplete mandibles were considered, only one left fragment (0.90%) exhibited Stafne's defect. Accurate identification of all examples of Stafne's bone defects in antiquity is thought to represent an important contribution to elucidate which factors may be responsible for this trait's cultural, ecological, temporal and geographical patterning. Copyright © 2010 John Wiley & Sons, Ltd.     

Calculus,periodontal disease and tooth decay among the prehispanic population from Gran Canaria

In the prehispanic Gran Canaria there are some anthropological differences between the coastal inhabitants who buried their dead mainly in tumuli, and those from the central mountains, mainly buried in caves. Some data, as the prevalence of auricular exostoses, and a different bone Ba/Sr ratio support the view that there were differences in economy and diet between both groups of islanders. Moreover, the proportion of carious teeth was significantly higher among the population buried in caves. In the present study we analysed the prevalence of dental calculus, periodontal disease and antemortem tooth loss in remains of 791 individuals belonging to the anthropological collection of the Museo Canario (Las Palmas). Calculus deposition was very frequent (88.51%), no differences existing between men and women or between those interred in tumuli or in caves. Age at death was the only parameter independently related to calculus deposition by stepwise multivariate analysis. Periodontal disease was observed in 66.78% of the population, significantly more in men (χ² = 4.88, P = 0.027). No differences existed between individuals buried in tumuli and in caves. Antemortem teeth loss was observed in 64.73% of individuals, no differences existing between men and women or between those interred in tumuli or in caves. There was a significant association between calculus and periodontal disease (χ² = 18.07, P < 0.0001). Both caries (χ² = 8.40, P = 0.004) and periodontal disease (χ² = 44.96, P < 0.0001) were associated with tooth decay. However, the proportion of teeth with calculus deposition (in relation to observed teeth) was significantly higher among the population buried in tumuli (Z = 3.18, P = 0.001), although no differences were observed when the proportion of antemortem lost teeth and alveoli with periodontal disease were compared among people buried in tumuli and in caves, but women showed significantly lower proportions of alveoli with periodontal disease and antemortem tooth decay. These data suggest that the population buried in caves had a different dietary pattern to that of those buried in tumuli, since calculus deposition -more frequent in the latter-may be related to the consumption of proteins. The results also point to the existence of differences in diet between men and women.     

Ancient DNA typing shows that a Bronze Age mummy is a composite of different skeletons

Excavations at Cladh Hallan, a Bronze Age-Iron Age settlement on South Uist in the Outer Hebrides off the west coast of Scotland, revealed the skeletons of two adults, a sub-adult and a child buried beneath the foundations of three roundhouses. Osteological and isotopic evidence has shown that the male adult skeleton is a composite made up of parts of at least three different individuals. To test the hypothesis that the female skeleton was also a composite we examined ancient DNA from four of its components: the skull, mandible, right humerus and right femur. Seven polymerase chain reactions (PCRs) were attempted, these covering positions 15,996–16,420, 16–132 and 232–368 of the mitochondrial DNA hypervariable I and II regions. Three PCRs were successful for each sample and a total of 55 sequences were obtained from the cloned products. After exclusion of possible contaminating sequences, the remaining 34 were compared. It was concluded that the mandible, humerus and femur come from different individuals. Insufficient data were obtained to draw conclusions regarding the origin of the skull. The presence of two composite skeletons at Cladh Hallan indicates that the merging of identities may have been a deliberate act, perhaps designed to amalgamate different ancestries into a single lineage.