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 t ... Читать далее