Prospects for the Synthesis of Ecological and Molecular-Genetic Approaches to the Problem of the Speciation of the Plague Microbe Yersinia pestis

Abstract

This review discusses two approaches to the problem of the recent origin of the plague microbe Yersinia pestis molecular-genetic (MG) and ecological. The MG approach proclaims uneven speciation (saltation), and horizontal gene transfer is considered to be the main factor of speciation. The ecological scenario of “Darwinian” speciation includes three types of genetic structures in the genome of Y. pestis: (1) a nonadaptive structure, which lost functions of the ancestral microbe Y. pseudotuberculosis O:1b during speciation, (2) a preadaptive structure, which supported transition into a new environment, and (3) a (neo)adaptive structure, which formed endogenously during speciation in the transitional environment—the host–parasite system of the Mongolian marmot–flea (Marmota sibirica–Oropsylla silantiewi). The ecological approach can integrate MG data and adequately interpret them in accordance with the postulates of the modern synthetic theory of evolution. The prospects for the determination of the mechanisms of the speciation process can be seen in the synthesis of ecological and MG approaches.