A GENETIC AND DEMOGRAPHIC-STUDY OF DAGEST AN HIGHLAND POPULATIONS ANDMIGRANTS TO LOWLANDS - THE RELATIONSHIP BETWEEN LEVELS OF INBREEDING,HOMOZYGOSITY, AND PHYSIOLOGICAL SENSITIVITY

This is a continuation of a series of papers devoted to studying the g enetic mechanisms of adaptation in migrants from isolated highland pop ulations of Dagestan to new ecological conditions (lowlands). This pap er describes the main results of studying the relationship between lev els of inbreeding, homozygosity, and physiological sensitivity. Earlie r, we found that decreased resistance to changing environmental factor s in migrants to lowlands from the Dagestan highlands was connected wi th their high level of homozygosity. The data obtained allow us to ass ume that missing links in this chain of events include, in addition to parameters of inbreeding level, parameters of neurophysiological sens itivity, including absolute and differential sensitivity of various an alyzers sensory systems, which are from 65 to 75% genetically determin ed. Migrants from highland auls (villages) to lowlands exhibited a dec reased rate of sensomotor reactions in response to light and sound of various intensities, as well as decreased differential color sensitivi ty in the long-, medium-, and short-wave ranges of the spectrum, compa red to highlanders. The results suggest the selective mortality of mig rants from highlands to lowlands during adaptation to new conditions. Those migrants who died were characterized by specific gene complexes that determined the characteristic features of expression of a number of interrelated polymorphic and quantitative traits. Thus, the high le vels of homozygosity and inbreeding were accompanied by a greater neur ophysiological sensitivity and lower indices of body weight and height .