[Ecological and geographical aspects of the plague agent Yersinia pestis speciation. Aspects écologiques et géographiques de la spéciation de l’agent de la peste Yersinia pestis].

Résumé

A new hypothesis of the origin of the plague microbe in the Mongolian bobak (Marmota sibirica Radde, 1862) populations in Central Asia during the Pleistocene is based on the ideas of its relative phylogenetic recency. The Late Pleistocene cooling, which induced a deep freezing of the grounds in southern Siberia, Mongolia, and Manchuria, is considered as an inducer of speciation. The main ecological factors of the plague microbe evolution include the species specific behavior of the Mongolian bobak during preparation to hibernation related to its occurrence in arid petrophytic landscapes and the larval parasitism of the flea Oropsylla silantiewi Wagn., 1898 in winter. Genesis of the plague foci is divided into two periods: natural-historical and biosocial. During the first period, the primari natural foci in Eurasia were formed and, during the second period, synanthropic (rat) and secondary natural foci appeared, with the participation of humans, in Africa, The New World, and on some tropical islands.