According to the analysis of polymorphism of mitochondrial DNA (mtDNA) in eastern Slavs, the frequency of the BamHI-3/AvaII-9/MspI-4 and BamHI-3/AvaII-13/MspI-4 mitotypes are 14% and 3%, respectively. The mitotype BamHI-3/MspI-4 in relation to the (+)AluI/15606 variant was demonstrated to be identical in European populations. It is assumed that the unimodal distribution of the difference values between all pairs of nucleotide sequences of the control mtDNA region that correspond to the BamHI-3/MspI-4 mitogroup indicates an association between the increase of mitotypic diversity in this mitogroup and the exponential growth of European populations in the Neolithic period.