Abstract
The allele frequencies of three allozyme loci, ADH, alpha-GPDH, and EST-6, were assessed in 18 natural populations of Drosophila melanogaster of Eastern Europe, the Caucasus, and Central Asia. The obtained data were combined with the data of other authors on ADH, alpha-GPDH, and EST-6 polymorphism in other regions of Eurasia analyzed to find the pattern of geographic differentiation on a continental scale. The ADH-S allele frequency was shown to be negatively correlated with latitude and the average rainfall of the driest calendar month and positively correlated with the average temperature of the coldest calendar month and the average rainfall of the wettest calendar month. The frequency of alpha-GPDH-S increased in the western part of Eurasia and was not associated with climatic variables. The frequency of EST-6-S decreased toward the center of the continent and was positively correlated with the temperature of the coldest month and with the rainfall of the driest month. The results are discussed in relation to the laboratory data on selective differences between the allozymes.