Based on data on 30 discrete-variable features, 58 skulls from the Ekvensky and 107 from the Uelensky burial grounds belonging to the ancient Bering Sea culture of Chukotka were studied. The similarity of the ancient Bering Sea populations not only with the modern Arctic, but also with the Baikal groups was found. This can be explained both by the contacts of the continental and Arctic Mongoloids of Siberia in ancient times, and by the commonality of their genetic roots. The results of a comparison of ancient populations of Chukotka with the Neolithic population of the Baikal region and southern Mongoloids suggest that the formation of a Proto-Eskimo-Aleutian ethno-cultural community could have occurred on the territory of Chukotka in the process of cultural and biological adaptation to the extreme conditions of Beringia of groups of both the intra-continental population of Siberia and migrants from South Asia and the Pacific region.

Keywords: anthropology, discrete-variable characteristics, ancient population of Chukotka, Chukchi, Eskimos.

When comparing modern and ancient populations based on craniometric data, we often encounter the phenomenon of epochal variability of traits, which distorts the real picture of the genetic relationships between these populations. More precise information about genetic succession can be obtained by using traits that reflect the genetic structure of populations and are not subject to time variability. This article is devoted to a comparative analysis of ancient Beringomorian and modern North Asian populations using discrete-variable features on the skull. Their use as" genetic markers " is quite justified, since discrete variations in the structure of the skull belong to a special class of morphological features - phenes. Population phenetics suggests that hair dryers reflect the genetic constitution of an individual, and their frequency reflects the genetic characteristics of a group of individuals. This makes it possible to extend genetic approaches and principles to populations whose genetic study is difficult or impossible [Timofeev-Resovsky and Yablokov, 1973; Timofeev-Resovsky, Yablokov, and Glotov, 1973].

Many indirect data suggest that variations in the skull structure occur during normal development and are to some extent determined genetically (Cheverad and Buikstra, 1981; Sjovold, 1984; Lane, 1977). In addition, numerous studies have shown that groups that are genetically distant from each other clearly differ in the frequency of these traits, while those that are genetically close show significant similarities. Thus, the use of population-genetic methods and approaches to the study of phenofunds of populations characterized by the frequencies of discrete features is very relevant for the study of human fossil populations. A detailed program and methodology for determining discrete-variable features on the skull were given by us earlier (Movsesyan, Mamonova, and Rychkov, 1975; Movsesyan, 2005).

58 skulls from the Ekvensky and 107 from the Uelensky burial grounds belonging to the ancient Bering Sea culture of Chukotka, a culture of the surviving Neolithic, were studied. For a comparative analysis, we used previously published data on modern and ancient Siberian peoples (Mamonova and Movsesyan, 1998; Movsesyan, 2005). It is important to note that the hour-

the tota of each trait in the population was calculated as the ratio of the number of its occurrence to the number of skulls on which it was possible to determine the trait. Statistical data processing was performed using the following methods:: 1) calculation of generalized genetic distances (d) by the method of M. Nei [Nei, 1972]; 3) classification analysis in the framework of the PHYLIP (Phylogeny Inference Package) package [Felsenstein, 1989]; 2) canonical analysis (the Kanoklass program developed by V. E. Deryabin).

For the first time, skulls from the Uelensky and Ekvensky burial grounds were studied by M. G. Levin [1962], who defined them as typically Eskimo, making on this basis a conclusion about the deep antiquity of the Eskimo type. The same conclusion was reached by G. F. Debets, who studied the question of the formation of the anthropological type of the Eskimos (1975). Odontological analysis of the Ancient Beringomorian series showed their similarity with each other and with groups of the Arctic race, as well as the preservation in both series of archaic features of the structure of the dental system characteristic of the Mesolithic - Bronze Ages (Zubov, 1969).

The similarity between the Ekwen and Uelen populations is also revealed by the frequencies of discrete-variable traits. The generalized genetic distance between them is rather small (d = 0.030). Apparently, the Uelen and Ekven burial grounds belonged to local populations of the same ethnic group. When compared with modern Arctic populations (Table 1). 1) it can be noted that the ancient be-

Table 1. Frequency distribution of discrete-variable traits in ancient populations of Chukotka and modern Arctic groups

Ringomorians are quite close to them and, what is very important, mainly in terms of the frequencies of those features that are characteristic of the Arctic groups, in contrast to the rest of the North Asian Mongoloids. For example, the Uelens and Ekwens, as well as the modern Eskimos, Chukchi, and Aleuts, are distinguished by increased frequencies of the supraorbital foramina (foramen supraorbitale), frontal foramina (foramen frontale), and mandibular ridge (torus mandibularis), a trait particularly characteristic of the Arctic race. The frequencies of the block awn (spina trochlearis), the insertion bone of the posterior fontanelle (os apicis Lambdae), and the insertion bones in the lambdoid suture (os Wormii suturae Lambdoideae) are relatively low in all Arctic groups. This similarity is also evident when calculating the genetic distances (d) between the Ancient Beringomorian and modern Siberian populations (Table 2).

At the same time, it is necessary to note the similarity of the ancient population of Chukotka with representatives of the Baikal race - Ulchi and Negidals. It is known that modern deer and coastal Chukchi also show features that, according to M. G. Levin (1958), indicate an admixture of the Baikal anthropological type. Comparing modern Arctic populations with continental North Asian Mongoloids by phenetic data, we obtain similar results (Table 3). Generalized genetic distances show that Eskimos are most closely related to coastal Chukchas. Chukchi coastal and deer are quite similar to each other. The Aleuts occupy a special position, as will be discussed below. Thus, the Chukchi and Eskimos form a rather isolated community, to which the Negidals and Ulchi are relatively close, except for the Aleuts. This picture is even more clearly shown in the diagram showing the relative position of modern Siberian populations in the space of canonical variables (Figure 1). Representatives of the Baikal race-Ulchi, Negidalians, Orochi, and Evenks-forming a compact group, were found to be in the region of positive values of the first variable along with Eskimos, Chukchi, and Aleuts. It is noteworthy that two independent methods of statistical analysis gave similar results.

Therefore, we can assume that the genetic contacts of the Arctic groups with the populations of the Baikal racial type belong at least to the era of the ancient Beringomorsk culture, and perhaps even to an earlier time, especially since there is some parallelism in the genetic and cultural relations of this region over the millennia. For example, S. I. Rudenko, who investigated the problem of the origin of ancient Beringomores-

Table 2. Genetic distances between the ancient population of Chukotka and modern Siberian ethnic groups

Table 3. Genetic distances between Arctic and continental Siberian populations

Figure 1. Results of canonical analysis of modern Siberian populations.

He suggested the possibility of its southern origins or connections, noting the proximity of the curvilinear Old Beringomorian ornament to the Amur one [1947]. It is assumed that this culture arose as a result of the synthesis of labretty ancient Eskimo cultures and labretty Ust-Belsky, which by the end of the first millennium BC spread to the northern and eastern coast of Chukotka. The Ust-Belskaya culture, in turn, is distinguished by both Eskimo-like features and features that indicate broad connections with neighboring regions of Siberia (Dikov, 1974). The Ust-Belsky burial ground is quite significant in this respect. I. I. Gokhman, studying the skull from it, found, along with the characteristics of the Arctic race, signs of the Baikal type [1961]. According to V. P. Alekseev, the Ust-Belsky skull is Proto-Eskimo, since it is characterized by undifferentiated anthropological features characteristic of the Eskimo ancestors [1967]. Thus, the phenetic proximity of the ancient Bering Sea populations to the modern Baikal groups revealed by us may reflect both the contacts of the continental and Arctic Mongoloids of Siberia and the commonality of their genetic roots.

It should be clarified that the methodology and principles of research organization that we use in ethnogenetic analysis are based on the approach to ethnic groups as population systems that have "genetic memory", i.e. preserve the original genetic characteristics. This important property of population systems was first discovered by A. S. Serebrovsky [1935] and later proved experimentally by Yu.G. Rychkov and Yu. P. Altukhov [Rychkov, 1969, 1973; Altukhov and Rychkov, 1970; Rychkov and Movsesyan, 1972; Altukhov and Pobedonostseva, 1978]. From the standpoint of this approach, the population system is represented as a subdivided population that has its own microevolutionary history and consists of subpopulations connected by a unity of origin. In the above-mentioned works, it is convincingly shown that it is characterized by genetic stability in time and space. Due to the historical conditionality of ethnogenetic processes, it is possible for ethnic communities to exist for a long time and to preserve the "memory" of previous stages of development in the gene pool of modern humanity for tens, hundreds and thousands of generations. Therefore, by averaging gene frequencies across populations that are part of the population system, it is possible to reconstruct the gene pool of the ancestral population, which makes it possible to compare modern and ancient groups not at the diachronic, but at the conditionally synchronous level.

Thus, the average characteristics of the Siberian racial groups, as well as of the Ancient Beringomorian populations, should to some extent reflect, according to the above approach, the genetic structure of hypothetical ancestral communities. In this case, comparing average characteristics is equivalent to comparing ancestral communities themselves to identify ancient genetic links between them. Such a comparative analysis showed almost the same degree of proximity of the Ancient Beringomorian populations to the Arctic and Baikal groups (Table 4). This seems to support the assumption that the ancient Bering Sea people are genetically related to more southern regions. At the same time, the continental groups, including the Baikal group, are much closer to the Neolithic population of the Baikal region. When constructing a generalized classification tree, the ancient Bering Sea people are combined with the Arctic populations (from the standpoint of the above approach - with their ancestral community), while the continental groups tend to belong to the Baikal Neolithic ones (Fig. 2). The similarity between the modern and ancient Arctic populations is particularly evident in the diagrams representing the frequency distribution of the 15 most polymorphic traits in individual groups and reconstructed ancestral communities (Figure 3).

So, judging by the results obtained, the paleophenetic data indicate that the genetic unity of the Arctic group populations is rooted in the distant past and that their phenofund preserves the "memory" of the carriers of the ancient Beringomorian culture. The latter, in turn, was one of the stages of the ancient Eskimo culture of sea St. John's wort, which arose in the II millennium BC on the Bering Sea coast of Chukotka in the process of adaptation to specific natural conditions. It is assumed that the creators of this culture were descendants of the Late Paleolithic Proto-Eskimo-Aleuts, at the end of

See Table 4. Genetic distances between the ancient population of Chukotka and modern Siberian racial groups

2. Generalized classification tree of modern and ancient Siberian Mongoloids.

3. Comparison of the phenetic structure of modern and ancient Arctic populations.

Frequencies of the following characters are plotted on clockwise radii: sutura frontalis, foramen frontale, spina processus frontalis (appendage), stenocrotaphia, os epiptericum, os postsquamosum, os asterion, os apicis Lambdae, os Wormii suturae Lambdoideae, os Wormii suturae occipito-mastoideum, processus interparietalis, tuberculum praecondylaris, foramen tympanicum, torus palatinus, sulcus mylohyoideus. Frequency 0 - in the center of the circle, 0.25-around the circumference.

In the late Pleistocene and early Holocene, they spread over the Beringian landmass from Asia to Northwestern America (Dikov, 1974).

However, the question of the genetic origins of the ancient Beringian population remains open. Following A. M. Zolotarev [1937], let us first try to find the genetic roots of proto-Eskimo-Aleuts in the inland regions of Northern Asia. Unfortunately, we do not have sufficient paleoanthropological data from the territories of Siberia close to Chukotka. However, it seems reasonable to compare the ancient Beringomorian series with skulls from Neolithic burials in the Baikal region dating back to the 7th-2nd millennium BC.

Comparative analysis showed that the "Paleoeskimos" phenetically differ from the Baikal Neolithic population no more than from the modern Arctic groups, revealing the greatest proximity to the carriers of the Kitoy culture (VII-VI millennium BC) (Table 5). On the diagrams representing the frequency distribution of discrete features in the ancient Bering Sea and Baikal populations, it is possible to determine the distribution of the frequency of discrete features in the note the similarity of the "phenetic patterns" of the Serov and Glazkov groups and the difference from them in the chronologically earlier Kitoi group, which to a certain extent is close to the reconstructed Ancient Chukchi ancestral community (Fig.

The results of the canonical analysis of modern and ancient Siberian populations are completely consistent with the previous ones and complement them (Figure 5). In the region of positive values of the second variable, the populations of the Arctic and Baikal races, as well as the Uelen, Ekven, and Kitoi groups are located. Representatives of the Central Asian and Uralic races found themselves together with the Serov and Glazkovians in the area of negative values.

Quite remarkable is the separation of the Aleutians from other Arctic groups in the space of canonical variables and their entry into the North Asian community. As you know, the Aleuts occupy a special place in the Arctic population system. Linguistically and ethnographically, they are similar to the Eskimos, but morphologically quite different from them. The morphological peculiarity of the Aleutians was noted in many works [Tokareva, 1937; Hrdlicka, 1944; Debets, 1951; Rychkov and Sheremetyeva, 1972; Sheremetyeva and Rychkov, 1978; Alekseev, 1981]. If G. F. Debets considered the Aleuts as a local form of the Arctic race, then in the classification of N. N. Cheboksary [1947] they are included in the same group as the Buryats-

See Table 5. Genetic distances between ancient populations of Chukotka and the Neolithic of the Baikal region

Tuvans and Mongols. Similar features of the Aleutians are also revealed by phenetic data. In the space of canonical variables, they are located much closer to the Tuvans and Evenks than to the Chukchi and Eskimos (see Figures 1, 5).

If we assume that the settlement of Chukotka came from Central Siberia, then the features of the Aleuts can be explained by the preservation in isolation of the characteristic features of the Proto-Eskimo-Aleutian type, which is close to the type of ancient inhabitants of Central Siberia. According to T. Ya. Tokareva, who noted the similarity of the Aleuts with the Evenks and the Neolithic population of the Baikal region, "the initial stage of the racial type of the Aleuts was the racial type known in the Baikal Neolithic and spread in a certain remote era over a vast territory that included the Bering Sea basin and, perhaps, Northwestern America" [1937, p. 58]. Supporting this point of view, V. P. Alekseev wrote:"...there is every reason to assume that the morphophysiological peculiarity of the Aleutians can be explained within the framework of the hypothesis of conservation of proto-mongoloid features" (Alekseev and Trubnikova, 1984, p. 75). Indeed, the Aleuts are quite close to the Neolithic population of the Baikal region, taking into account the average characteristics of the Neolithic groups (d= 0.036).

When the average characteristics of ancient populations are included in the canonical analysis, the Neolithic population of Chukotka shifts towards the Arctic groups (Figure 6), which corresponds to the structure of the classification tree (see Figure 2). The Neolithic population of the Baikal region moves to the center of the range of continental Mongoloids. The Aleuts, on the other hand, due to the presence of the Neolithic ancestral community of Chukotka, find themselves, along with other groups of the Arctic race, in the region of positive values of the second and negative values of the first canonical variable, while at the same time being located at an equal distance from the Neolithic population of the Baikal region and the Central Asian populations. It can be concluded that the average characteristics of ancient populations do to a certain extent reflect the original gene pools: the Proto-Eskimo-Aleutian community and the ancestral community of the continental Mongoloids of Siberia. Apparently, Proto-Eskimo-Aleuts,

4. Comparison of the phenetic structure of ancient populations of Chukotka and the Neolithic of the Baikal region. The clockwise radii display the frequencies of the same features as shown in Figure 3.

5. Results of canonical analysis of modern and ancient populations of Siberia.

6. Results of the canonical analysis of modern and ancient populations of Siberia, taking into account the average characteristics of Neolithic groups.

As well as the Neolithic populations of the Baikal region, they were descendants of the proto-Mongoloid Paleolithic population of Siberia, originally unified in its genetic structure, which created local Neolithic cultures in the process of developing vast territories of Northern Asia.

The results obtained are confirmed in the data of archeology, according to which the boundaries of the Baikal-Lena area began to expand intensively at the end of the IV millennium BC. The Lena-Aldan Neolithic culture spread through the upper reaches of the Lena River, along the upper reaches of the Angara River down and further to the north-west and north, to Khatanga and the lower reaches of the Lena River, and also east along the Okhotsk coast to the north-eastern tip of the Asian continent (Chernetsov, 1973).

The research of A. P. Okladnikov (1948) established the existence of cultural relations between the Baikal region in the Neolithic period and the remote regions of Western Siberia and the regions west of the Urals. The researcher also finds similarities with the Baikal Neolithic in the Neolithic cultures of the Yenisei, linking this to the spread of groups of the Early Neolithic population of the Baikal region to the south and west. Moreover, there are signs of extensive contacts between the carriers of the Kitoi culture and the inhabitants of rather remote areas both in the west and in the east (Okladnikov, 1974). From the Baikal region, the Lena River was apparently occupied by the territory of Northern Yakutia, where Neolithic monuments show a clear similarity with the Baikal ones. In turn, the Neolithic of Yakutia had a great influence on the Neolithic of the Chukchi Peninsula, and this largely determined the nature of subsequent cultures of Chukotka associated with the ethnogenesis of the north-eastern Paleoasiates (Dikov, 1974).

At the same time, it is impossible to ignore the possibility of preserving the southern and Pacific components of the representatives of the Arctic group. A number of authors suggested that it was through Beringia that Pacific elements penetrated to the Americas (Zubov, 2002; Neves et al., 2003). We compared the modern and ancient populations of Chukotka with the southern and Pacific Mongoloids (Table 6). In our material, no southern admixture is detected in the modern Arctic groups, but the ancient populations of Chukotka show a certain affinity to the Burmese and Papuans. It is noteworthy that the Pacific complex was also identified in the ancient Bering Sea people using an alternative system of cranioscopic features (Kozintsev, 1988). Consequently, the formation of the Proto-Eskimo-Aleutian ethno-cultural community could have occurred on the territory of Chukotka in the process of cultural and biological adaptation to the extreme conditions of Beringia of groups of both the intra-continental population of North Asia and migrants from South Asia and the Pacific region.

Table 6. Genetic distances between Arctic populations of Siberia, southern Mongoloids, and Pacific groups

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The article was submitted to the Editorial Board on 01.09.11, in the final version-on 30.09.11.

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