The aim of this work is to study directional asymmetry (DA) in skeletal samples of ancient pastoralists of the Altai forest-steppe. Two groups were studied, one of which belongs to the Advanced Bronze Age, the other to the Scythian period. As a result of studying the DA indicators of the transverse dimensions of the long bones of the limbs and clavicles, sex and chronological differences were established, reflecting the specifics of the physical activity of pastoralists. In men of both chronological periods, manual loads were bilateral, mainly of a power nature. Women's work, especially in Scythian times, required more frequent use of the dominant hand. Women also experienced asymmetric loads on their legs in the mediolateral plane. The probability of the longitudinal dimensions of the arm bones in the Bronze Age group is low, while the Scythian age is high, which is probably determined by chronological differences in the level of environmental and / or genetic stress.

Keywords: bilateral asymmetry, physical activity, long limb bones, pastoralists, Bronze Age, Scythian time, Altai.

Introduction

The degree of bilateral asymmetry of paired features of the human skeleton can serve as an indicator of the biological adaptation of paleopopulations to various factors of the external and internal environment. There are three main types of bilateral asymmetry-fluctuating asymmetry (FA), directional asymmetry (DA) and antisymmetry (AnS), which differ in the nature of the variability of the difference in the paired sizes of the right and left sides. FA refers to small random differences between sides that have a normal distribution around the mean of 0. In DA, which is also called fixed skewness, one side is on average larger than the other, and the prevailing size is more common on the same side (the distribution is normal, the mean value is significantly different from 0). In AnS (or random skewness), there are statistically significant differences between the parties, but the dominant side is determined randomly (the distribution is bimodal or flat-topped, the average value is 0) [Palmer and Strobeck, 1986, 2003]. Different types of asymmetry often interact. When studying paleopopulations, FA and DA are of primary importance.

FA reflects the level of developmental instability that increases under environmental and genetic stress [Harris and Nweeia, 1980; Livshits and Kobyliansky, 1991; Hershkovitz et al., 1993; Markow and Martin, 1993; Gray and Marlowe, 2002; Guatelli-Steinberg, Sciulli, Edgar, 2006; Schaefer et al., 2006; DeLeon, 2007; Hoover and Matsumura, 2008; Graham et al., 2010; Ozener,

This work was supported by the Russian Foundation for Basic Research (project No. 11 - 06 - 00360a) and the Russian Foundation for Basic Research (project No. 11-06-00360a). 12 - 01 - 00159).

2010]. However, it is very difficult to measure FA in the presence of significant DA methodically [Palmer, 1994; Graham et al., 1998], which imposes certain restrictions on the choice of features. When studying FA in paleopopulations, dental and cranial features are usually used.

Bone structure of the human skeleton is associated with functional asymmetry of the body (motor, sensory, mental). Motor asymmetry manifests itself in the form of preferential use when performing unilateral movements of a certain (dominant) hand, in the functional specialization of the legs, in the development of motor qualities and the speed of formation of conditioned reflexes. DA of the tubular bones of the extremities is largely formed as a result of functional adaptation to mechanical factors. The relationship between DA and mechanical stress of the limb bones, especially the upper ones, is widely used in the study of physical exertion in paleopopulations due to their economic structure, as well as the tender division of labor. However, most of these studies were carried out on materials originating from foreign territories and related mainly to hunter-gatherers and farmers [Ruff and Jones, 1981; Bridges, 1989; Fresia, Ruff, Larsen, 1990; Stirland, 1993; Sakaue, 1998; Mays, 1999; Bridges, Blitz, Solano, 2000 Stock and Pfeiffer, 2004; Westcott and Cunningham, 2006; Sladek et al., 2007; Wanner et al., 2007; Kujanova et al., 2008; Maggiano et al., 2008; Sparacello and Marchi, 2008; Pomeroy and Zakrzewski, 2009; Weiss, 2009; Sparacello et al., 2011].

The aim of this work is to study the directional asymmetry of long limb bones and clavicles in skeletal samples of Bronze and Early Iron Age cattle breeders of the forest-steppe Altai.

Material and methods

The long bones of the limbs and collarbones of the Andronovo culture (AK) of the Middle Bronze Age and the Old Alei culture (SK) of the Scythian period of the forest-steppe Altai were studied. The economic basis of both groups was cattle breeding. The AK skeletal sample includes materials from the Barsuchikha-1, Zolotushka, Malopanyushevsky, Manzhikha-5, Teleutsky Vzvoz-1, Firsovo-14, Chekanovsky Log-2 and 10 burial grounds; the SK sample includes materials from the Firsovo-14 and Tuzovsky Bugry-1 burial grounds. The collections are kept in the anthropology room of the Altai Museum of Archeology and Ethnography of the Altai State University.

The gender and age of individuals were determined by standard methods. No significant age differences were found between the studied samples. We measured paired bones of the upper and lower extremities (humeral, radial, ulnar, femoral, tibial), as well as clavicles without deformity and obvious pathology, with fully grown epiphyses. During measurements, the limb bones were oriented in the mediolateral and sagittal planes in accordance with the schemes of K. Ruff (Ruff and Hayes, 1983; Ruff, 2002). The middle of the tibial diaphysis was determined based on the total length (T1), the rest - from the largest (H1, R1, U1, F1). Measurement accuracy of longitudinal dimensions - up to 0.5 mm, transverse diameters of the diaphysis - up to 0.05 mm.

In addition to the standard dimensions, which are numerically designated according to R. Martin (Alekseev, 1966), several additional dimensions adopted in the study of DA were used. The latter include the average diameter of the middle of the diaphysis, equal to the half-sum of the sagittal and medio-lateral ones. In addition, on the humerus bones, the diameters of the diaphysis (sagittal, mediolateral, and middle) were measured at the level of 35% of the maximum length from the distal end, on the tibia-the minimum and maximum diameters of the middle of the diaphysis. The specified dimensions are marked with Latin letters.

To calculate the measurement error, the bones of seven individuals were measured three times at intervals of several weeks. The error was calculated using the method of T. D. White [White and Folkens, 2005], according to which deviations from the average value were averaged and expressed as a percentage of its value. For most parameters, it was less than 0.5 % and could not significantly affect the results and conclusions of this study (Table 1).

For quantitative measurement of DA, the standardized directional skewness index %DA was used, which was calculated using the formula:

where R is the size of the right side and L is the size of the left side.

This formula is widely used in [Steele, Mays, 1995; Cuk, Leben-Seljak, Stefancic, 2001; Mays, 2002; Auerbach, Ruff, 2006; Blackburn, Knusel, 2006; Sladek et al., 2007; Auerbach, Raxter, 2008; Kujanova et al., 2008; Jaskulska, 2009; Pomeroy and Zakrzewski, 2009; Weiss, 2009; Stock et al., 2013], allows you to directly compare the degree of asymmetry of features with different absolute values, in particular, the length of bones and the width of diaphysis. The %DA indicator has positive values when the right side is larger than the left, and negative values when the left side is larger than the right.

Measurement errors ( nTable 1. = 7), %

* For full feature names, see Table 2.

To check the normality of the distribution of %DA values, the Lilliefors criterion was used. In the absence of significant deviations from normality, a single-sample t-test was used to check whether the average value of %DA actually differs from 0. If the distribution of %DA values significantly deviated from the normal distribution, the nonparametric Wilcoxon test was used to check the significance of differences in the paired sizes of the right and left sides. The nonparametric Mann-Whitney U-test was used to assess the significance of gender and diachronic differences.

When calculating the proportion of individuals with right - and left-sided dominance of humerus length, only the values of %DA > 0.5% were taken into account, which avoids the influence of measurement error and GA [Auerbach and Ruff, 2006]. The significance of inter-group differences in these indicators was assessed on the basis of criterion 2 ².

The relationships between DA of longitudinal and transverse bone sizes were analyzed on the basis of Pearson correlation coefficients, which were calculated using regression residuals of logarithmically transformed dimensions of the right and left sides [Ibid.]. All calculations were performed using STATISSTTCA 10 software.

The scale of inter-group variability of %DA values of humeral, radial, femoral, and tibia bones was used for data on nine groups of a wide geographical range, presented in the work of B. Auerbach and K. Ruff [Auerbach and Ruff, 2006]. In addition, data on %DA of humerus bones and clavicles of 15 other groups published by B. Auerbach and M. Rachter (Auerbach and Raxter, 2008) were used. Most of these materials date from a time close to modern times.

Results

Upper limbs and collarbone. In the male and female Andronovo groups, DA of the clavicle length is absent, the longitudinal dimensions of the arm bones show a slight right-sided dominance, and only the value of %DA of the humerus length in the total sample reaches the level of statistical significance (Table 2). In the Old Alean samples (male, female, and total), the right humerus, radius, and ulna bones are longer than the left ones, while the right clavicle bones are shorter (Table 3). Differences in %D and humerus length are observed between the Bronze Age and Scythian age groups (men - p = 0.035; women-p = 0.011 1). In the Scythian period, the proportion of individuals with right - sided dominance of the length of the humerus bones increases (the total sample - p = 0.021), with left - sided-decreases (women-p =0.021). 0.020; total sample - p = 0.025) (Table 4).

The range of transverse dimensions of the diaphysis in comparison with the length of the bones as a whole varies more widely. In the female SC group, the clavicle diaphysis shows a distinct right-sided asymmetry, in the AK samples, the corresponding values of %DA have increased variability, and in women there is a tendency to left-sided dominance.

Of the ten transverse dimensions of the humeral diaphysis, seven in the AK sample and four in the SK sample show significant right-sided asymmetry. The sagittal diameter of the middle of the H6c diaphysis has the highest positive values of %DA in all groups (with and without gender). Significant asymmetry is shown not only by the absolute dimensions, but also by the cross-sectional indicators of the middle of the diaphysis H6 : H5 and H6c : H6b (Table 5).,

Table 2. Indicators of directional asymmetry of the clavicles and long limb bones in the Andronovo sample

End of Table 2

Notes: n1, n2 are the number of observations in the male and female groups, respectively; the first value of %DA is the median, the second (in parentheses) is the average; significance of differences between the right and left sides:index a - p < 0.05, b-p < 0.01, c-p < 0.001; italics indicate values whose distribution significantly deviates from the normal one; bold indicates values that show significant sex differences; values of features that show significant chronological differences are underlined.

Table 3. Indicators of directional asymmetry of the clavicles and long bones of the extremities in the Old Italian sample*

Continuation of Table 3

End of Table 3

* See note. go to Table 2.

1. Diagrams of the span %DA of the length of the humeral (HI) and ulnar (U1) bones. Chronological differences. a - men; b-women; a, b-25-75 %; c-median.

as well as the width of the upper and lower epiphyses. There are significant correlations between the asymmetry of the longitudinal and transverse dimensions of the humerus bones (Table 6). Right-sided asymmetry of the latitudinal dimensions R4 and R4a is characteristic of the radial bone diaphysis. In the samples of AK %DA of the sagittal diameter of the middle of the diaphysis, R5a has significant negative values. The diaphysis cross-sectional indicators R5 : R4 and R5a : R4a also show significant asymmetry in both male and female groups. The width of the distal epiphysis of the radial bones is less asymmetric than the width of the diaphysis. In the ulnar diaphysis, the highest values of %DA have latitudinal dimensions, which tend to be left-sided dominant (with the exception of the female sample of SC).

When comparing %DA of the transverse dimensions of the clavicles and bones of the upper extremities in men and women, as well as in representatives of the Bronze Age and Scythian time, statistically significant differences were revealed. Sex differences are noted in the asymmetry of the clavicle diaphysis-vertical diameter C4 (p = 0.048) in the AK sample and circumference C6 (p = 0.043) in the SK sample. Diaphysis of the humerus bones in women

humeral bones ( The ratio of individuals with right - and left-sided dominance Table 4. %

Note: italics indicate the values for which the AK and SK groups differ significantly (p < 0.05).

See Table 5. Average values of long bone diaphysis cross-section indicators limbs

Notes: values of indicators on the right/left side; in parentheses - the number of observations; significance of differences %of indicators: index a - p < 0.05, b-p < 0.01, b-p < 0.001; italics indicate values that show significant gender differences; bold - chronological.

Table b. Correlation coefficients DA of longitudinal and transverse dimensions of long bones upper extremities

Notes: the population size is indicated in parentheses; values that are reliable at the level of p < 0.05 are shown in bold.

they are more asymmetrical. In the AK sample, significant sex differences are shown by the value of %DA of the sagittal diameter of the middle of the H6c diaphysis (p = 0.040) and the H6c index : H6b (p = 0.049), in the SK sample - the sagittal diameter at the level of 35% of the length (p = 0.036) and the circumference of the middle of the H7a diaphysis (p = 0.043). In addition, women of the Scythian period had more asymmetric dimensions of the vertical diameter of the heads of the humerus bones of the NUDE (p = 0.041) (Fig. 2). Diachronic differences can be traced in the asymmetry of the circumference (p = 0.003). the vertical (p = 0.035) and average (p = 0.037) diameters of the clavicles, the width of the middle of the humeral diaphysis H6b in women (p = 0.044), the width of the lower epiphysis H4 in male (p = 0.025), female (p = 0.003) and total (p = 0.000) samples (Fig.Sex differences in %DA of the radial bone diaphysis are characteristic of the AK group: in women, the width of the diaphysis R4a (p = 0.041) and the index R5a : R4a (p = 0.009) are less asymmetric. Male samples differ in the asymmetry of the cross-section of the middle of the radial diaphysis: in the earlier group, the values of %DAR4a (p = 0.002), R5a (p = 0.037) and R5a : R4a (p = 0.000) are higher (Figure 4).

Leg bones. The left femur and tibia are longer than the right. The width of the femoral diaphysis F7a is characterized by left-sided asymmetry, which is more pronounced in women. The sagittal diameter of the middle of the F6 diaphysis in Scythian males has a significant right-sided asim-

2. Diagrams of the %DA span of the transverse dimensions of the clavicles (C)and humerus (H).

Gender differences, a-men; b-women; a, b-25-75%; c-median; d - range without emissions; e - emissions.

3. Diagrams of the %DA span of the transverse dimensions of the clavicles (C) and humerus (H) bones. Chronological differences. See Figure 2 for additional information.

4. Diagrams of the %DA range of the radial (R) and ulnar (U) diaphysis. Gender and chronological differences. See Figure 2 for additional information.

yandex. metrica". Sex differences in %DA of the average femoral diameter in the UK sample approach the level of statistical significance (p = 0.09). Men of the Bronze Age and women of the Scythian age show a significant asymmetry in the pilastria index F6 : F7a. The width of the lower epiphysis of the femur does not have a dominant direction.

Mediolateral (as well as minimal) diameters of the tibial diaphysis tend to be right - sided asymmetry, while sagittal (as well as maximal) diameters tend to be left-sided. These trends are more pronounced in women, especially in the AK sample. In the female groups, T9 : T8 and T9a: T8a indicators of the diaphysis cross-sections also show significant asymmetry. Most of the sample values of %DA of the width of the epiphysis of the tibia are close to zero. Sex differences are noted by %DA of the maximum diameter of the middle of the tibial diaphysis TD max in the AK sample (p = 0.049) and the minimum diameter TD min in the SK sample (p = 0.011), diachronic-by %DA T8a (between sex-combined samples, p = 0.017) and the index of cnemia T9a : T8a (between female samples, p = 0.034) (Figure 5).

For a weighted estimate of %DA values in skeletal samples of Altai cattle breeders, it is necessary to correlate them with the scale of intergroup differences. Figures 6 and 7 show the vertical lines reflecting the range of variability (min-max) of %DA median values in geographically and partly chronologically different groups (Auerbach and Ruff, 2006; Auerbach and Raxter, 2008). As the graphs show, the inter-group range of %DA variability in the transverse dimensions of diaphysis is much larger than in the longitudinal dimensions of bones. The length of the bones of the upper limbs and clavicles in the SC sample has relatively high values of %DA (except for the radius in men), in the AK sample - low. If the 24 groups used for comparative analysis are arranged in ascending order of %DA of the length of the humerus bones, then in this sequence the Andronovo male sample will be ahead of seven of them, the female sample will be ahead of six, while the Old Italian ones will be ahead of 19 and 17, respectively. The asymmetry of the transverse dimensions of the humeral diaphysis in men is extremely low, in women it is below average. According to this indicator, the Andronovo women's sample is ahead of three groups out of 24, and the Staroaleyskaya group is ahead of nine. By the value of %DA of the average diameter of the middle of the radial diaphysis, AK men are ahead of seven groups out of nine, women - four; SC men-three, women-six. The strong left-sided asymmetry of the width of the clavicle diaphysis in the female Andronovsky sample may be explained by its low level of sensitivity.

5. Diagrams of the % DA range of the tibial diaphysis (T) Sex and chronological differences. See Figure 2 for additional information.

Figure 6. %DA level of Altai samples on the scale of intergroup differences. Clavicles and bones of the upper extremities.

Figure 7. %DA level of Altai samples on the scale of intergroup differences. Bones of the lower extremities.

Figure 8. Sexual dimorphism %DA of the average diameter of the middle of the humeral diaphysis (difference in values in male and female samples). Groups: 1-AK; 2 - SK; 3 - 11 - see: Auerbach and Ruff, 2006; 12 - 26-see: Auerbach and Raxter, 2008.

9. Sexual dimorphism %DA of the mean diameter of the middle of the radial shaft (difference in values in male and female samples). Groups: 1-AK; 2-SK; 3-11-see: Auerbach and Ruff, 2006.

small population. The sexual dimorphism %DA of the transverse dimensions of the humeral diaphysis in the studied samples is average in absolute value (Fig. 8), while the radial dimorphism is high (Fig. 9).

The length of the leg bones has close to zero or small negative values of %DA. In the female samples of AK and SK, an extremely high left-sided asymmetry of the transverse dimensions of the femoral diaphysis is noted. A specific feature of the Altai groups is also the zero or positive %DA values of the transverse dimensions of the tibial diaphysis (see Figure 7).

Discussion

The increase in the size of paired limb bones reflects their functional inequality in the formation of general motor behavior. The leading limbs have more strength, higher accuracy, speed and coordination of movements, the non-leading ones are more often used for support and support. In most people, the right hand is dominant. According to various estimates, the proportion of right-handed people among the modern population is 85-90 % (Porac and Coren, 1981; Annett, 1985; Bratina and Dobrokhotova, 1988).

The bones of the leading hand are longer and thicker. The proportion of individuals with right-sided dominance of the longitudinal dimensions of the humerus (or the total length of the humerus and radius) in archaeological populations often corresponds to the frequency of right-handed people among the modern population (Schultz, 1937; Steele and Mays, 1995; Cuk, Leben-Seljak and Stefancic, 2001; Auerbach and Ruff, 2006). Functional dominance of the right hand is also associated with inversion in the direction of asymmetry of the clavicle length [Auerbach and Raxter, 2008].

Functional asymmetry of the body, which determines the direction of differences in the size of paired limb bones, is genetically determined. However, populations with the same percentage of right-handed people can significantly differ in the amount of morphological asymmetry, depending on the nature and level of habitual physical activity. The role of the mechanical factor in the formation of the morphological structure of hand bones is well studied in high-class athletes [Jones et al., 1977; Krahl et al., 1994; Haapasalo et al., 1996, 2000; Kontulainen et al., 2003; Shaw and Stock, 2009a; et al.] and is confirmed by the results of studies "ordinary " population [Blackburn and Knusel, 2006; Ozener, 2007, 2010].

When studying skeletal materials of a wide geographical range, it was found that different structural components of bones (longitudinal dimensions, width of diaphysis and articular surfaces) significantly differ in DA value.

The greatest asymmetry is shown by the width of the diaphysis, the smallest-by the length of the bones, the epiphysis (articular and periarticular surfaces) occupy an intermediate position [Trinkaus, Churchill, Ruff, 1994; Auerbach, Ruff, 2006]. There are no correlations between bone length asymmetry and diaphysis width [Auerbach and Ruff, 2006]. The greater plasticity of the diaphysis width under the influence of external factors is supported by a significant intra-group and inter-group variability in the asymmetry of these sizes [Auerbach Ruff, 2006; Auerbach, 2007; Auerbach and Raxter, 2008]. Bone growth in length has a higher degree of genetic channeling than the width of the diaphysis (Hallgrimsson, Willmore, and Haall, 2002). Feedback between the degree of sewerage

the size of bones and the influence of mechanical stimuli on them during the development of DA is clearly manifested in the process of growth and development of the body. In children under one year of age, the humerus bones are mostly symmetrical, the asymmetry is fluctuating and occurs more often in the width of the diaphysis and epiphysis than in the longitudinal dimensions. Directional asymmetry in the structure of the humerus develops parallel to the functional one. At the same time, the right - sided dominance of the diaphysis width is formed most rapidly, and the bone length is formed most slowly (Blackburn, 2004).

Thus, a decrease or increase in the asymmetry of the width of the diaphysis of the extremities reflects differences in the nature and degree of physical exertion within the group and between groups. The asymmetry of the bones of the upper extremities is enhanced if there is a "division of labor" between the hands, and vice versa, it is smoothed out when the nature of work creates comparable bilateral loads. The degree of laterization of manual loads also depends on the complexity of tasks. When performing simple movements of a predominantly power nature, the difference in the use of dominant and non-dominant hands is reduced. If the task is complex and requires fine motor skills, high coordination of movements, and visual control, the leading hand is more often used [Bryden, 2002].

According to the literature data, the level of %DA of the width of the diaphysis of the bones of the upper extremities shows some changes in connection with the type of farm and the degree of settlement. In men, higher values of %DA of the humerus bones are observed in the least sedentary groups [Auerbach, 2007]. In most farmers, the asymmetry of the humerus or clavicle diaphysis is less pronounced than in hunter-gatherers (Auerbach and Raxter, 2008).

In the male samples of Altai cattle breeders, the %DA values of the transverse dimensions of the humerus and clavicle diaphysis are very low, in the female samples they are higher, especially in the SC. An analysis of the strength of the humerus bones shows that manual loads in men of both groups, as well as in Andronovo women, were high, and in Old Alei women - low [Tur, 2013]. Thus, in men, manual loads were distributed bilaterally and were mainly power loads. Women's work seemed to require more precise movements, so the dominant hand was used more often. Sex differences in the degree of asymmetry of manual loads indicate a high level of tender division of labor in the paleopopulations of Altai pastoralists. The decrease in manual labor among women in the Scythian period, accompanied by an increase in the role of the dominant hand, may be associated with technological improvements in the field of women's labor.

The opposite direction of dominance of the transverse dimensions of the radial and ulnar diaphysis, observed in men of both groups, apparently reflects an uneven distribution of loads between the forearm bones. Male samples of the Bronze Age and Scythian age differ mainly in %DA of the size and especially the shape of the cross-section of the radial bone diaphysis. This is explained by the fact that the mechanisms of adaptation to physical exertion of the proximal and distal segments of the long bones of the hands are not the same. If on the humerus, in addition to changing the shape of the cross-section of the diaphysis, its external contour expands, then on the forearm bones, the shape mainly changes, which ensures an optimal energy balance between the strength of the bone and its weight [Stock, 2006; Shaw and Stock, 2009a]. The humerus bones more adequately reflect the value of manual loads than the forearm bones [Ibid.]. Differences in the level of DA of the shape of the cross-section of the radial diaphysis and the width of the lower humeral epiphysis between the male samples of AK and SK indicate that the specifics of manual loads in male cattle breeders in the Scythian period changed somewhat.

The variability of DA in the longitudinal dimensions of the long bones of the upper extremities has a complex etiology. In the Altai samples, the % DA values of the length of the humerus, radius, and ulna bones are higher in women than in men, but these differences do not reach a statistically significant level, possibly due to the limited number of observations. Large right-sided asymmetry of the longitudinal dimensions of the arm bones in women is usually observed in other groups as well [Auerbach and Ruff, 2006; Auerbach and Raxter, 2008], although there are exceptions [Steele and Mays, 1995; Papaloucas et al., 2008]. This is explained by the fact that the percentage of left-handed people is usually higher among men [Bryden, 1982; McManus, 1991; Porac and Coren, 1981], and this indicator may vary at the population level.

Analysis of the longitudinal dimensions of the upper limb bones in Altai cattle breeders reveals significant diachronic changes. In the male and female samples of the Scythian period, the %DA values for the length of the humerus bones are higher, while in the female and forearm samples, the values are higher. The proportion of individuals with right-sided dominance of the longitudinal dimensions of the humerus bones in the Old Alei group corresponds to the proportion of right-handed people in the modern population, while in the Andronovo group it is much lower. Diachronic changes in the DA of the longitudinal dimensions of the hand bones could occur under the influence of mechanical stress. This is supported by some statistically significant correlations between %DA of the longitudinal and transverse dimensions of the humerus bones in the studied samples (Table 6). The positive impact of high temperatures on the upper back of the shoulder is shown in Fig.

physical loads on the length of the dominant arm bones were previously observed in high-class tennis players [Krahl et al., 1994], but such data are still rare in the literature. At the same time, when studying the age dynamics of changes in the length of hand bones in the modern population, sharp fluctuations in the level of asymmetry in the pubertal period (11-14 years) were revealed, indicating the heterogeneity of the influencing factors [Chermit and Aganyants, 2006]. This suggests that the longitudinal dimensions of the limb bones, despite the high degree of genetic canalization, become more sensitive to mechanical stimuli during puberty. The absence of correlations between the asymmetry of bone length and diaphysis width in a large skeletal sample combining materials from different parts of the world [Auerbach and Ruff, 2006] may be explained by its heterogeneity and the presence of multidirectional trends in individual local-territorial groups. Obviously, not all of them had manual exercises at puberty that were high enough to affect the length of their arm bones.

In addition to the mechanical factor, the level of environmental and genetic stress can affect the change in the longitudinal dimensions of the hand bones. The neurological substrate for right-handedness is formed in the early stages of intrauterine development. According to ultrasound data, 92 % of fetuses suck on the right thumb (Hepper, Shahidullah, White, 1991). Changes in the "programmed" level of motor laterization of the hands, in particular, an increase in the frequency of left-sided dominance, can occur as a result of impaired stability of intrauterine development with increased homozygosity for many loci or unfavorable environmental conditions (an infectious agent), and especially with a combination of these factors [Markow, 1992; Yeo, Gangestad, 1993]. According to available data, in some traditional societies of the Far North, the frequency of left-handed people reached 33.8 % (Stepanov, 1988).

Environmental stress, apparently, can affect the change in the length of the bones of the hands and during the maturation of the skeleton. Normally, the fusion of epiphyses with metaphyses of paired limb bones occurs synchronously, but in some paleopopulations with a high level of markers of episodic and cumulative stress, significant DA and FA rates of synostosis of the humerus bones were noted. Most often, earlier synostoses were formed on the right side (Albert and Greene, 1999). Thus, the decrease in the degree of laterization of arm bone length in the samples of Altai pastoralists of the Bronze Age could be caused by an increase in the level of environmental and / or genetic stress. To verify this assumption in the future, it is necessary to analyze features with an "ideal" FA.

The functional disequilibrium of the lower limbs is not as obvious as that of the upper ones. It manifests itself in the fact that one leg (leading, dominant) is more often used for movements that require motor coordination, while the other (supporting) is used to support the body and maintain balance [Gabbard and Hart, 1996; Sadeghi et al., 2000]. In most right-handed people, the right leg is the leading one (Gabbard and Iteya, 1996). The direction of functional and morphological asymmetry of the lower limb bones does not coincide. The bones of the left, supporting, leg often have larger dimensions ("cross-symmetry"). This is due to the fact that the non-dominant leg under the influence of body weight is subjected to a higher load than the dominant one. According to literature data, the left femur has a longer length (39 %) and thicker diaphysis (50 %), the tibia has no dominant direction, and the diaphysis is thicker on the left side in some groups (Auerbach and Ruff, 2006), and on the right side in others (Auerbach, 2007). The reduction in the size of the bones of the lower extremities in comparison with the upper ones is weakly expressed. Obviously, locomotion creates more symmetrical loads and, in addition, limits the divergence of leg bones along the length.

The cross-sectional shape and strength of the diaphysis of the long bones of the lower extremities correlates with the level of mobility [Ruff, 1987; Stock and Pfeiffer, 2001; Stock, 2006; Shaw and Stock, 2009b]. The female samples of AK and SK, in contrast to the male ones, are characterized by very high negative values of % DA of the femoral diaphysis width. Usually, the degree of left-sided asymmetry of the average diameter of the femoral diaphysis is less than 1.0 % [Auerbach and Ruff, 2006]. However, in some women's groups, this indicator has increased values, in particular, in pre-industrial Europeans [Ibid. and the Amerinds, where hunting and gathering were combined with agriculture (Wescott and Cunningham, 2006; Auerbach, 2007). Since the level of mobility affects the sagittal rather than the mediolateral diameter of the femur (Ruff, 1987; Stock and Pfeiffer, 2001; Stock, 2006), an increase in the left-sided asymmetry of the latter may be associated with the specifics of physical activity during a sedentary lifestyle.

According to the world data summary published by B. Auerbach and K. Ruff, the thickness of the tibial diaphysis is left-sided dominant (Auerbach and Ruff, 2006). However, it was soon established that this trend is not universal [Auerbach, 2007]. This is confirmed by the results of studying the Altai samples. The instability of the direction of dominance of the thickness of the tibial diaphysis can be explained by the fact that the morphological adaptation of the bones of the distal segments of the lower extremities, as well as

As with the former, it occurs mainly due to a change in shape [Stock, 2006].

Analysis of the size and shape of the cross-section of the tibial diaphysis in the AK and SK samples reveals sexual and chronological differences. In women, the left bone has a smaller mediolateral (minimum) diameter and/or a larger sagittal (maximum), as a result of which it is characterized by a more laterally flattened (platycnemic) shape. Increased platycnemia of the left tibia was also observed in some other groups [Ruff and Jones, 1981; Bagashev, 1993; Wanner et al., 2007], but the factors determining the variability of this trait remain unexplored. Data on the asymmetry of loads on the lower extremities during walking and running due to different functional specialization of the right and left legs (mobilization and stabilization) are contradictory [Sadeghi et al., 2000; Seeley, Umberger, Shapiro, 2008]. In addition, one should not exclude the possible influence on the development of DA of the leg bones of factors that are not directly related to the level of physical activity. Further data accumulation is required.

Conclusion

The study of limb bone activity in populations of a wide geographical and chronological range provides data necessary for understanding the general mechanisms of functional adaptation of the bone system, as well as for a comparative analysis of physical activity of the population depending on the economic structure and gender division of labor. The results of the study of skeletal materials of pastoralists who lived in the forest-steppe Altai in the Bronze Age and Scythian times confirm the existing ideas that the range of transverse dimensions of the diaphysis varies more widely than the length of bones. At the same time, it was found that in the proximal segments of the limbs, DA is manifested in the size and shape of the diaphysis cross - section, in the distal ones-mainly in the shape. There may be correlations between the DA of the longitudinal and transverse dimensions of the hand bones. The width of the tibial diaphysis shows right-sided dominance. Analysis of the transverse dimensions of the bones of the limbs and clavicles reveals both sexual and chronological differences.

The results of the analysis of the maximum width of the diaphysis of the bones of the upper extremities indicate that for male cattle breeders, bilateral manual loads of a predominantly power nature were characteristic. Women's work required more precise movements, and therefore the dominant hand was used more often, the role of which increased significantly in Scythian times. Women also experienced more asymmetric loads on their legs.

The proportion of the longitudinal dimensions of the arm bones in the Bronze Age group is low, while the proportion of the Scythian age is high. Chronological differences in the degree of laterization of these sizes can be determined by the impact of a mechanical factor, as well as changes in the level of environmental and / or genetic stress. To clarify their etiology in the future, it is necessary to study FA.

List of literature

Alekseev V. P. Osteometriya: Metodika antropologicheskikh issledovaniy [Osteometrics: Methods of anthropological research], Moscow: Nauka Publ., 1966, 252 p.

Bagashev A. N. Ethnic anthropology of the Tobol-Irtysh Tatars. Novosibirsk: Nauka Publ., 1993, 152 p. (in Russian)

Bragina N. N., Dobrokhotova T. A. Functional asymmetries of a person. - M.: Medicine, 1988. - 240 p.

Stepanov Yu. M. The role of functional brain asymmetry in the regulation of the psychophysiological state in the conditions of the Far North. biol. nauk. Novosibirsk, 1988, 16 p. (in Russian)

Tur S. S. Biomechanical approach to the study of physical activity of ancient pastoralists of the forest-steppe Altai // Vesti, Archeology, Anthropology and Ethnography. -2013. - N 3. - p. 95-102.

Chermit K. D., Aganyants E. K. Symmetry, harmony, adaptation. - Rostov-on-Don: North. - Kavkaz, scientific center of Higher Education. shkoly Publ., 2006, 303 p. (in Russian)

Albert A.M., Greene D.L. Bilateral asymmetry in skeletal growth and maturation as an indicator of environmental stress // Am. J. of Physical Anthropology. - 1999. - Vol. 110. - P. 341 - 349.

Annett M. Left, right, hand and brain: The right-shift theory. - New Jersey: Lawrence Erlbaum, 1985. - 474 p.

Auerbach B. Human skeletal variation in the New World during the Holocene: effects of climate and subsistence across geography and time: unpublished PhD Thesis. - Baltimore: Johns Hopkins University, 2007. - 1076 p.

Auerbach B.M., Raxter M.H. Patterns of clavicular bilateral asymmetry in relation to the humerus: variation among humans // J. of Human Evolution. - 2008. - Vol. 54. -P. 663 - 674.

Auerbach B.M., Ruff C.B. Limb bone bilateral asymmetry: variability and commonality among modern humans // J. of Human Evolution. - 2006. - Vol. 50. - P. 203 - 218.

Blackburn A. Bilateral asymmetry of the humerus during growth and development // Am. J. of Physical Anthropology. - 2004. - Vol. 145. - P. 639 - 646.

Blackburn A., Knusel C.J. Hand dominance and bilateral asymmetry of the epicondylar breadth of the humerus: A test in a living sample // Current Anthropology. - 2006. - Vol. 47, N 2. - P. 377 - 382.

Bridges P.S. Changes in activities with the shift to agriculture in the Southeastern United States // Current Anthropology. - 1989. - Vol. 30. - P. 385 - 394.

Bridges P.S., Blitz J.H., Solano M.C. Changes in long bone diaphyseal strength with horticultural intensification in West-

Central Illinois // Am. J. of Physical Anthropology. - 2000. -Vol. 112. - P. 217 - 238.

Bryden M.P. Laterality: Functional asymmetry in the intact brain. - N. Y: Academic Press, 1982. - 319 p.

Bryden P.J. Lateral preference, skilled behaviour and task complexity: Hand and foot // Side bias: A neuropsychological perspective. -N.Y.; Boston; Dordrecht; L.; Moscow: Kluwer Academic Publishers, 2002. - Ch. 9. - P. 225 - 248.

Cuk T., Leben-Seljak P., Stefancic M Lateral asymmetry of human long bones // Variability and Evolution. - 2001. -Vol. 9. -P. 19 - 32.

DeLeon V.B. Fluctuating asymmetry and stress in a medieval Nubian population // Am. J. of Physical Anthropology. - 2007. - Vol. 132. - P. 520 - 534.

Fresia A.E., Ruff C.B., Larsen C.S. Temporal decline in bilateral asymmetry of the upper limb on the Georgia coast // The Archaeology of Mission Santa Catalina de Guale. - N.Y.: American Museum of Natural History, 1990. - Pt. 2: Biocultural Interpretations of a Population in Transition. - P. 121 - 132. -(Anthropological Papers of The American Museum of Natural History; N 68).

Gabbard C., Hart S. A question of foot dominance // J. of General Psychology. - 1996. - Vol. 123, N 4. - P. 289 - 296.

Gabbard C., Iteya M. Foot laterality in children, adolescents and adults // Laterality. - 1996. - Vol. 1. - P. 199 - 205.

Graham J.H., Emlen J.M., Freeman D.C., Leamy L.J., Kieser J.A. Directional asymmetry and the measurement of developmental instability // Biol. J. of the Linnean Society. -1998. - Vol. 64. - P. 1 - 16.

Graham J.H., Raz S., Hel-Or H., Nevo E. Fluctuating asymmetry: Methods, theory, and applications // Symmetry. -2010. - N 2. - P. 466 - 540.

Gray P.B., Marlowe E. Fluctuating asymmetry of a foraging population: the Hadza of Tanzania // Annals of Human Biology. - 2002. - N 29. - P. 495 - 501.

Guatelli-Steinberg D., Sciulli P.W., Edgar H.H. Dental fluctuating asymmetry in the Gullah: tests of hypotheses regarding developmental stability in deciduous vs. permanent and male vs. female teeth // Am. J. of Physical Anthropology. - 2006. - Vol. 129. - P. 427 - 434.

Haapasalo H., Kontulainen S., Sievanen H., Kannus P., Jarvinen M., Vuori I. Exercise-induced bone gain is due to enlargement in bone size without a change in volumetric bone density: a peripheral quantitative computed tomography study of the upper arms of male tennis players // Bone. - 2000. - Vol. 27. - P. 351 - 357.

Haapasalo H., Sievanen H., Kannus P., Heinonen A., Oja P., Vuori I. Dimensions and estimated mechanical characteristics of the humerus after long-term tennis loading // J. of Bone and Mneral Research. - 1996. - Vol. 11. - P. 864 - 872.

Hallgrimsson B., Willmore K., Hall B.K. Canalization, developmental stability, and morphological integration in primate limbs // Yearbook of Physical Anthropology. - 2002. -Vol. 45. - P. 131 - 158.

Harris E.E., Nweeia M. Dental asymmetry is a measure of environmental stress in the Ticuna Indians of Colombia // Am. J. of Physical Anthropology. - 1980. -Vol. 53. -P. 133 - 142.

Hepper P.G., Shahidullah S., White R. Handedness in the human fetus // Neuropsychologia. - 1991. - Vol. 28. -P. 1107 - 1111.

Hershkovitz I., Livshits G., Monskona D., Arensburg B., Kobyliansky E. Variables affecting dental fluctuating asymmetry in human isolates // Am. J. of Physical Anthropology. -1993. - Vol. 91. - P. 349 - 365.

Hoover K.C., Matsumura H. Temporal variation and interaction between nutritional and developmental instability in prehistoric Japanese populations // Am. J. of Physical Anthropology. - 2008. - Vol. 137. - P. 469 - 478.

Jaskulska E. Skeletal bilateral asymmetry in a medieval population from Deir an-Naqlun (Nekloni), Egypt // Bioarchaeology of the Near East. - 2009. - N 3. - P. 17 - 26.

Jones RE, Priest J.D., Hayes W.C., Tichenor C.C., Nagel D. A. Humeral hypertrophy in response to exercise // J. of Bone and Joint Surgery. - 1977. - Vol. 59. - P. 204 - 208.

Kontulainen S., Sievanen H., Kannus P., Pasanen M., Vuori I. Effect of long-term impact-loading on mass, size and estimated strength of humerus and radius of female racquet-sports players: a peripheral quantitative computed tomography study between young and old starters and controls // J. of Bone and Mineral Research. - 2003. - Vol. 18. - P. 352 - 359.

Krahl H., Michaelis U., Pieper H.G., Quack G., Montag M. Simulation of bone-growth through sports - a radiologic investigation of the upper extremities in professional tennis players // Am. J. of Sports Medicine. - 1994. - Vol. 22. -P. 751 - 757.

Kujanova M., Bigoni L., Veleminska J., Veleminsky P. Limb bones asymmetry and stress in medieval and recent populations of Central Europe // Int. J. of Osteoarchaeology. - 2008. - Vol. 18. - P. 476 - 491.

Livshits G., Kobyliansky E. Fluctuating asymmetry as a possible measure of developmental homeostasis in humans: A review // Human Biology. - 1991. -Vol. 63. - P. 441 -446.

Maggiano I., Schultz M., Kierdorf H., Sierra Sosa Т., Maggiano C., Tiesler Bios V. Cross-sectional analysis of long bones, occupational activities and long-distance trade of the Classic Maya from Xcambo - archaeological and osteological evidence // Am. J. of Physical Anthropology. - 2008. -Vol. 136. - P. 470 - 477.

Markov T.A. Human handedness and the concept of developmental stability // Genetica. - 1992. - Vol. 87. - P. 87 - 94.

Markow T.A., Martin J.E. Inbreeding and developmental stability in a small human population // Annals of Human Biology. - 1993. - Vol. 20. - P. 389 - 394.

Mays S. A biomechanical study of activity patterns in a medieval human skeletal assemblage // Int. J. of Osteoarchaeology. - 1999. - Vol. 9. - P. 68 - 73.

Mays S. Asymmetry in metacarpal cortical bone in a collection of British post-medieval human skeletons // J. of Archaeological Science. - 2002. - Vol. 29. - P. 435 - 441.

McManus I.C. The inheritance of left-handedness // Biological asymmetry and handedness: Ciba Foundation Symposium. - Chichester: Wiley, 1991. - Vol. 162. - P. 251 - 267.

Ozener B. Biomechanical pressures and upper extremity asymmetry: a study on young laborers // Collegium Antropologicum. - 2007. - Vol. 31. -P. 693 - 699.

Ozener B. Fluctuating and directional asymmetry in young human males: Effect of heavy working condition and socioeconomic status // Am. J. of Physical Anthropology. -2010. - Vol. 143. - P. 112 - 120.

Palmer A.R. Fluctuating asymmetry analyses: a primer // Developmental instability: Its origins and evolutionary implications: Proceedings of the Int. Conf., Tempe, Arizona, 14 - 15 June 1993. - Dordrecht: Kluwer Academic Publishers, 1994. -P. 335 - 364.

Palmer A.R., Strobeck C. Fluctuating asymmetry: Measurement, analysis, patterns // Annual Review of Ecology and Systematics. - 1986. - Vol. 17. - P. 391 - 421.

Palmer A.R., Strobeck C. Fluctuating asymmetry analysis revisited // Developmental instability: causes and consequences. - Oxford: Oxford University Press, 2003. - P. 279 - 319.

Papaloucas M., Papaloucas A., Tripolitsioti A., Stergioulas A. The asymmetry in length between right and left humerus in humans // Pakistan J. of Biological Sciences. - 2008. -Vol. 11. - P. 2509 - 2512.

Pomeroy E., Zakrzewski S.R. Sexual dimorphism in diaphyseal cross-sectional shape in the medieval Muslim population of Ecija, Spain, and Anglo-Saxon Great Chesterford, UK // Int. J. of Osteoarchaeology. - 2009. - Vol. 19. - P. 50 - 65.

Porac C., Coren S. Lateral preferences and human behavior. - N. Y: Springer-Verlag, 1981. - 283 p.

Ruff C. Sexual dimorphism in human lower limb bone structure: relationship to subsistence strategy and sexual division of labor // J. of Human Evolution. - 1987. -Vol. 16. -P. 391 - 416.

Ruff C.B. Long bone articular and diaphyseal structure in Old World monkeys and apes. I: Locomotor effects // Am. J. of Physical Anthropology. - 2002. - Vol. 119. - P. 305 - 342.

Ruff C.B., Hayes W.C. Cross-sectional geometry of Pecos Pueblo femora and tibiae - a biomechanical investigation: 1. Method and general patterns of variation // // Am. J. of Physical Anthropology. - 1983. - Vol. 60. - P. 359 - 381.

Ruff C.B., Jones H. Bilateral asymmetry in cortical bone of the humerus and tibia - sex and age factors // Human Biology. - 1981. - Vol. 53. - P. 69 - 86.

Sadeghi H., Allard P., Prince F., Labelle H. Symmetry and limb dominance in able-bodied gait: a review // Gait and Posture. - 2000. - Vol. 12. - P. 34 - 45.

Sakaue K. Bilateral Asymmetry of the humerus in Jomon people and modern Japanese // Anthropological Science. -1998. - Vol. 105, N 4. - P. 231 - 246.

Schaefer K., Lauc E., Mitteroecker P., Gunz P., Bookstein F.L. Dental arch asymmetry in an isolated Adriatic community // Am. J. of Physical Anthropology. - 2006. - Vol. 129. -P. 132 - 142.

Schultz A.H. Proportions, variability and asymmetries of the long bones of the limbs and the clavicles in man and apes // Human Biology. - 1937. - Vol. 9. - P. 281 - 328.

Seeley M.K., Umberger B.R., Shapiro R. A test of the functional asymmetry hypothesis in walking // Gait and Posture. - 2008. - Vol. 28. - P. 24 - 28.

Shaw C.N., Stock J.T. Habitual throwing and swimming correspond with upper limb diaphyseal strength and shape in modern human athletes // Am. J. of Physical Anthropology. -2009a. - Vol. 140. - P. 160 - 172.

Shaw C.N., Stock J.T. Intensity, repetitiveness, and directionality of habitual adolescent mobility patterns influence the tibial diaphysis morphology of athletes // Am. J. of Physical Anthropology. - 2009b. - Vol. 140. - P. 149 - 159.

Sladek V., Berner M., Sosna D., Sailer R. Human manipulative behavior in the Central European Late Eneolithic and Early Bronze Age: humeral bilateral asymmetry // Am. J. of Physical Anthropology. - 2007. - Vol. 133. - P. 669 - 681.

Sparacello V., Marchi D. Mobility and subsistence economy: a diachronic comparison between two groups settled in the same geographic area (Liguria, Italy) // Am. J. of Physical Anthropology. - 2008. - Vol. 136. - P. 485 - 495.

Sparacello V.S., Pearson O.M., Coppa A., Marchi D. Changes in skeletal robusticity in an iron age agropastoral group: The samnites from the Alfedena necropolis (Abruzzo, Central Italy) // Am. J. of Physical Anthropology. -.2011. -.Vol. 144. -P. 119 - 130.

Steele J, Mays S. Handedness and directional asymmetry in the long bones of the human upper limb // Int. J. of Osteoarchaeology. - 1995. - Vol. 5. - P. 39 - 49.

Stirland A. J. Asymmetry and activity-related change in the male humerus // Int. J. of Osteoarchaeology. - 1993. -Vol. 3. - P 105 - 113.

Stock J.T. Hunter-gatherer postcranial robusticity relative to patterns of mobility, climatic adaptation, and selection for tissue economy // Am. J. of Physical Anthropology. -2006. -Vol. 131. - P. 194 - 204.

Stock J.T., Pfeiffer S.K. Long bone robusticity and subsistence behavior among Later Stone Age foragers of the forest and fynbos biomes of South Africa // J. of Archaeological Science. - 2004. - Vol. 31. - P. 999 - 1013.

Stock J.T., Pfeiffer S.K. Linking Structural Variability in Long Bone Diaphyses to Habitual Behaviors: Foragers From the Southern African Later Stone Age and the Andaman Islands // Am. J. of Physical Anthropology. - 2001. - Vol. 115. - P. 337 - 338.

Stock J.T., Shirley M.K., Sarringhaus L.A., Davies E.G., Shaw C.N. Skeletal evidence for variable patterns of handedness in chimpanzees, human hunter-gatherers, and recent British populations // Annals of the New York Academy of Sciences. - 2013. - Vol. 1218. - P. 86 - 99.

Erinkaus E., Churchill S.E., Ruff C.B. Postcranial robusticity in Homo. II: Humeral bilateral asymmetry and bone plasticity // Am. J. of Physical Anthropology. - 1994. -Vol. 93. - P. 1 - 34.

Wanner I.S., Sierra Sosa T., Alt K.V., Eiesler Bios V. Lifestyle, occupation, and whole bone morphology of the pre-Hispanic Maya coastal population from Xcambo, Yucatan, Mexico // Int. J. of Osteoarchaeology. - 2007. - Vol. 17. -P. 253 - 268.

Weiss E. Sex differences in humeral bilateral asymmetry in two hunter-gatherer populations: California amerinds and British Columbian amerinds // Am. J. of Physical Anthropology. - 2009. - Vol. 140. - P. 19 - 24.

Wescott D.J., Cunningham D.L. Temporal changes in Arikara humeral and femoral cross-sectional geometry associated with horticultural intensification // J. of Archaeological Science. - 2006. - Vol. 33. -P. 1022 - 1036.

White T.D., Folkens P.A. The human bone manual. - N. Y: Elsevier Academic Press, 2005. - 464 p.

Gangestad S.W. Yeo R., Developmental origins of variation in human hand preference // Genetica. - 1993. - Vol. 89. -P. 281 - 296.

The article was submitted to the editorial Board on 18.11.13, in the final version-on 26.12.13.

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