Olga A. Fedorchuk

Introduction. Canonical discriminant analysis, based on the mean values of the traits, is widely used by anthropologists. These analyses use standard deviation means, as well as standard correlation coefficients. The question of the comparability of the results of such analysis with the results based on individual values remains open. Moreover, the existing intergroup variability in correlation coefficients can lead to altered analysis results when applying the correlation matrix calculated for the specific under analysis groups.

This study compares the results of three variants of the canonical discriminant analysis: based on individual data, based on average values and a generalized (species-specific) correlation matrix, and based on average values and a regional (calculated for a certain region) correlation matrix.

Materials and methods. Data from 48 ethno-territorial groups from the Old World were used. The series are dated close to modern times, from the 16th to the 20th century. Twenty-five craniometric linear features have been measured. For canonical analysis on individual data we used the R language package, and for average data analysis the MultiCan software was used.

Results. The results of the two analyses performed on individual data and on average data turned out to be quite similar.

A comparison of the results of a series of discriminant analyses carried out on samples of the three major races using different correlation matrices reveals some small differences in the mutual arrangement of groups. In general, the distribution of samples in the scatter plots, as well as the standardized coefficients of discriminant functions coincide, regardless of the type of initial data.

Conclusion. In general, it may be concluded that the use of both individual values and sample averages in most cases leads to the same results. When individual values are used, the results may be distorted as a result of a strong reduction in the number of samples. Also, sample differentiation in this case is strongly influenced by a higher real intra-group variability. © 2023. This work is licensed under a CC BY 4.0 license.

Introduction. Paleoanthropological studies of Medieval North African materials are extremely few. Despite the large number of international expeditions working in the region, very few results of craniometric and osteometric data are presented. This is partly due to the loss of practical measurement skills in European anthropological schools in the second half of the 20th century, partly due to the difficulties of studying the graves of the Islamic period. Several seasons of work of the Nubian Archaeological and Anthropological Expedition of the Research Institute and the Museum of Anthropology of Lomonosov Moscow State University on the Southern Necropolis of the medieval site Derakheyb (Republic of Sudan) were devoted to the study of this population. The purpose of the publication is characteristics of the medieval population buried in the Southern Necropolis of the Derakheyb site due to osteological features and introducing the new data.

Materials and methods. The material is the bones of the postcranial skeleton of adult individuals (14 men and 9 women). The technique corresponds to the classical program in the modification of V.P. Alekseev (a total of 74 signs and 16 pointers). The reconstruction of the body length was carried out, the total body dimensions were described, and the proportion indicators were calculated. For intra-group analysis, the principal component method was used, which was carried out using individual data using the R language.

Results and discussion. The male population is characterized by average total body size and shoulder width, while the female series is relatively narrow-shouldered. In the male series, the distal parts of the arms and legs are elongated relative to the proximal ones, and the lower limbs are elongated relative to the upper ones. The women's series featured a more graceful physique. The distal part of the leg is elongated relative to the proximal one, as in the male group; there is also some shortening of the upper limbs relative to the lower ones. Body length varies between 166 cm for men and 156 cm for women.

Conclusion. According to osteometry data, the medieval population of the city of Derakheyb can be characterized as heterogeneous, the individuals that stand out mainly correspond to those that stood out according to craniological data. The male part of the population is medium-massive, and the female part is graceful. The entire sample is characterized by shortened lower limbs relative to the arms, as well as elongated distal parts of the arms and legs relative to the proximal ones, which reflects one of the features of the tropical adaptive type. © 2024. This work is licensed under a CC BY 4.0 license

Introduction. The task of differentiating groups using various statistical methods remains relevant due to the limitations often encountered with standard algorithms. Some of these limitations, such as the assumption of normal distribution of traits and the absence of high correlations between them, can be circumvented by the method based on step-wise partitioning – decision trees.

Materials and methods. In this study, this method was tested on 15 linear dimensions of the skull and 16 indices calculated based on them. The entropy index was chosen as the criterion of heterogeneity. The craniometric features used correspond to the standard methodology adopted in Russian anthropology. The data consisted of average values of craniometric dimensions from 39 ethno-territorial groups from 13 macro-regions of the Old World.

Results and discussion. The results of the differentiation show that indices have a greater weight than linear features. Five linear dimensions and seven indices participated in the differentiation. Three indices were based on the overall dimensions of the braincase (M.1, M.8, M.17), and four indices included the bizygomatic width (M.45). The first split occurs based on the transverse facial index (46:45), separating the groups of Northern, Middle, Central Asia, and Europe from the groups of Africa, Eastern, Southeast, and Southern Asia.

Conclusion. The study demonstrates the high differentiating ability of indices, particularly the transverse facial index, fronto-zygomatic index, and height-length index. The iterative differentiation system allows for a more informative separation of groups, as different combinations of features demonstrate effectiveness at different hierarchical levels of taxonomy. © 2025. This work is licensed under a CC BY 4.0 license