10 research outputs found
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The genetic history of the Southern Arc: a bridge between West Asia and Europe
By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe
Sex determination by 3DGM of the cranium in modern greek population
The aim of this study is to determine the regions of the cranium where sexual dimorphism is most pronounced by using three-dimensional geometric morphometric methods and to investigate the effectiveness of this method in determining sex from the shape of the cranium. The study sample consisted of 176 crania of known sex (94 males, 82 females) belonging to individuals wholived in Greece during the 20th century. The three-dimensional coordinates of 80 ecto-cranial landmarks and 30 semi-landmarks were digitized using a Microscribe 3DX contact digitizer. Goodall's F-test was performed in order to compare statistical differences in shape between malesand females. Generalized Procrustes Analysis (GPA) was used to obtain the size and shape variables for statistical analysis. Shape, size and form analyses were carried out by logistic regression and discriminant function analysis. Results indicate that there are statistically significant shape differences between the sexes in all regions except for the nasal. For instance, the orbit aperture of males is parallel to the frontalplane while in females it is positioned in a slightly sagittal direction. The jugale points are relatively further apart in males. In addition, nasospinale and nasion shift more anteriorly in males. Females in the region of the temporal bones are narrower and the axis forming the frontal and occipital bone is more elongated; the frontal bone is more vertical. In males, the palate is deepest and more elongated; the cranial base is shortened. The highest shape classification rate was obtained from the craniofacial region while the lowest from the palate. In particular, the accuracy of sexing for the skull as a whole was 78.4%; the cranial base 79%; the palate 68.9 %; the upper-face 83.1%; the orbits 72.7%; the vault 79%; and the midsagittal curve of the neurocranium 70.2%. In all cases the centroid size was smaller in females than males. More over, it was found that sexual dimorphism is mainly contributed by size differences in the skull as a whole, the base, the upper face and the vault region. As anticipated, in all regions, the classification accuracy improves when both size and shape are combined. The findings presented here constitute a firm basis upon which further research can be conducted. The highest shape classification rate was obtained from the craniofacial region while thelowest from the palate. In particular, the accuracy of sexing for the skull as a whole was 78.4%; the cranial base 79%; the palate 68.9 %; the upper-face 83.1%; the orbits 72.7%; the vault 79%; and the midsagittal curve of the neurocranium 70.2%. In all cases the centroid size was smaller in females than males. Moreover, it was found that sexual dimorphism is mainly contributed by sizedifferences in the skull as a whole, the base, the upper face and the vault region. As anticipated, in all regions, the classification accuracy improves when both size and shape are combined. The findings presented here constitute a firm basis upon which further research can be conducted.Σκοπός της συγκεκριμένης μελέτης ήταν να καθοριστούν οι περιοχές του κρανίου, όπου ο φυλετικός διμορφισμός είναι πιο έκδηλος, εφαρμόζοντας τριδιάστατες γεωμετρικές μορφομετρικές μεθόδους καθώς και να ερευνηθεί η αποτελεσματικότητα αυτής της μεθόδου για τον προσδιορισμό του φύλου βάσει του σχήματος του κρανίου. Το δείγμα αποτελείτο από 176 κρανία ελληνικού πληθυσμού που έξησε τον 20ο αιώνα, γνωστού φύλου (94 αρσενικά, 82 θηλυκά) και ηλικίας. Τα 80 αναφορικά σημεία στην εξωτερική επιφάνεια του κρανίου καθώς και τα 30 ψεύδο-αναφορικά σημεία, ψηφιοποιήθηκαν με τη χρήση του MicroScribe 3DX. Για τον έλεγχο ύπαρξης στατιστικά σημαντικών διαφορών στο σχήμα μεταξύ θηλυκών και αρσενικών ατόμων, εφαρμόστηκε τοGoodall's Fτεστ και χρησιμοποιήθηκε η Γενικευμένη ανάλυση Προκρούστη (GPA), προκειμένου να εξαχθούν οι μεταβλητές σχήματος και μεγέθους. Η μείωση του όγκου των δεδομένων επιτεύχθηκε με την ανάλυση κύριων συνιστωσών, ενώ για την κατάταξη των μεταβλητών του κρανίου σε αρσενικά και θηλυκά άτομα χρησιμοποιήθηκαν δύο μέθοδοι, η διαχωριστική ανάλυση και η λογιστική παλινδρόμηση. Τα αποτελέσματα όλων των περιοχών του κρανίου, με εξαίρεση τη ρινική περιοχή,υποδεικνύουν ότι υπάρχουν στατιστικά σημαντικές διαφορές στο σχήμα μεταξύ των δύο φύλων. Παραδείγματος χάριν, οι οφθαλμικοί κόγχοι στους άνδρες είναι σχετικά παράλληλοι στο μετωπιαίο επίπεδο συγκριτικά με τις γυναίκες. Τα αναφορικά σημεία jugale είναι πιο απομακρυσμένα μεταξύ τους στα αρσενικά άτομα και τα nasospinale και nasion πιο πρόσθια μετατοπισμένα, ενώ τα θηλυκά άτομα, στην περιοχή των κροταφικών οστών είναι λιγότερο πεπλατυσμέσμα και ο νοητός άξονας που σχηματίζουν το μετωπιαίο και το ινιακό οστό πιο επιμήκης. Επιπλέον, οι γυναίκες έχουν σχετικά χαμηλότερη και ευρύτερη υπερώα. Το υψηλότερο ποσοστό ταξινόμησης στον προσδιορισμό του φύλου λήφθηκε από την κρανιοπροσωπική περιοχή, ενώ το χαμηλότερο από την περιοχή της υπερώας. Πιο συγκεκριμένα, η ακρίβεια στον προσδιορισμό του φύλου σύμφωνα με το κρανίο συνολικά ήταν 78,4%, τη βάση του κρανίου 79%, της υπερώας 68,9% το προσωπικό κρανίο 83,1%, τους οφθαλμκούς κόγχους 72,7%,το θόλο του κρανίου 79% και την καμπύλη του κρανίου 70,2%. Σε όλες τις περιπτώσεις το κεντροειδές (το μέγεθος) ήταν μικρότερο για τα θηλυκά άτομα συγκριτικά με τα αρσενικά.Επιπλέον, διαπιστώθηκε ότι το μέγεθος παίζει σημαντικό ρόλο στο φυλετικό διμορφισμό στο κρανίο ως σύνολο, στο θόλο του κρανίου, στο προσωποκράνιο καθώς και στο βασικράνιο. Τέλος,όπως αναμενόταν, σε όλες τις υπό μελέτη περιοχές τα ποσοστά επιτυχούς ταξινόμησης αυξάνονταν,όταν η ανάλυση περιελάμβανε και τη μεταβλητή του μεγέθους. Τα συμπεράσματα αυτής της μελέτης αποτελούν μια σταθερή βάση επάνω στην οποία μπορεί να πραγματοποιηθεί περαιτέρω έρευνα
An attempt to predict tooth crown height using cementoenamel junction diameters and implications in the quantitative study of dental wear
AgeEst: An open access web application for skeletal age-at-death estimation employing machine learning
The present study tests the accuracy of commonly adopted age-at-death estimation markers based on the morphology of the pubic symphysis, iliac auricular surface and cranial sutures on a contemporary documented skeletal collection from Greece (81 males and 59 females). Machine learning techniques are used to assess whether a) machine learning classification models can correctly classify skeletons into their correct age group and b) machine learning regression models can predict the correct age to a satisfactory degree. The constructed models are used in a web application (AgeEst), where users can easily employ them to make predictions for their own skeletal assemblages. The results show that the use of machine learning improves age predictions in terms of bias and inaccuracy compared to the direct application of the original methods. However, there is a strong misclassification of middle-aged individuals, stressing the inherent biases both of the skeletal markers traditionally used in age-at-death prediction and of machine learning methods that, in our case, tend to classify most individuals to one of the two extremes (young or old). We would like to invite colleagues to share with us raw data from other skeletal collections to expand the training dataset to address to some extent issues of age mimicry, while the notebook used for the analysis as well as the code used to construct the web application are openly available to promote the further development of this or similar applications by other scholars
Sex determination by three-dimensional geometric morphometrics of the palate and cranial base
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Ancient DNA from Mesopotamia suggests distinct Pre-Pottery and Pottery Neolithic migrations into Anatolia
We present the first ancient DNA data from the Pre-Pottery Neolithic of Mesopotamia (Southeastern Turkey and Northern Iraq), Cyprus, and the Northwestern Zagros, along with the first data from Neolithic Armenia. We show that these and neighboring populations were formed through admixture of pre-Neolithic sources related to Anatolian, Caucasus, and Levantine hunter-gatherers, forming a Neolithic continuum of ancestry mirroring the geography of West Asia. By analyzing Pre-Pottery and Pottery Neolithic populations of Anatolia, we show that the former were derived from admixture between Mesopotamian-related and local Epipaleolithic-related sources, but the latter experienced additional Levantine-related gene flow, thus documenting at least two pulses of migration from the Fertile Crescent heartland to the early farmers of Anatolia
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A genetic probe into the ancient and medieval history of Southern Europe and West Asia
Literary and archaeological sources have preserved a rich history of Southern Europe and West Asia since the Bronze Age that can be complemented by genetics. Mycenaean period elites in Greece did not differ from the general population and included both people with some steppe ancestry and others, like the Griffin Warrior, without it. Similarly, people in the central area of the Urartian Kingdom around Lake Van lacked the steppe ancestry characteristic of the kingdom's northern provinces. Anatolia exhibited extraordinary continuity down to the Roman and Byzantine periods, with its people serving as the demographic core of much of the Roman Empire, including the city of Rome itself. During medieval times, migrations associated with Slavic and Turkic speakers profoundly affected the region
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A genetic probe into the ancient and medieval history of Southern Europe and West Asia
Literary and archaeological sources have preserved a rich history of Southern Europe and West Asia since the Bronze Age that can be complemented by genetics. Mycenaean period elites in Greece did not differ from the general population and included both people with some steppe ancestry and others, like the Griffin Warrior, without it. Similarly, people in the central area of the Urartian Kingdom around Lake Van lacked the steppe ancestry characteristic of the kingdom’s northern provinces. Anatolia exhibited extraordinary continuity down to the Roman and Byzantine periods, with its people serving as the demographic core of much of the Roman Empire, including the city of Rome itself. During medieval times, migrations associated with Slavic and Turkic speakers profoundly affected the region