Two branches, ecological and genetic, in studying the species population structure: History, problems, and solutions

This paper presents a brief history of two different methods for studying the species population structure. The first method employs ecological markers that characterize population-specific environmental conditions, as well as biological features of populations. The second one involves genetic markers: DNA and RNA fragments, allozymes, etc. The problem of combining these two methods is discussed. A two-step approach is suggested for studying the species population structure using both the ecological and genetic markers. Firstly, the studied part of the species range is subdivided into so-called ecogeographic units (EGUs) according to environmental gradients, life strategies, and other characteristics that presumably associate with adaptation gradients and interpopulation gene flows. Secondly, the EGUs are tested genetically by using the data on multiple population samples that represent population segments within each of the ecogeographic units. The notion of representative samples with respect to the population structure, hierarchy of EGUs–populations, strategies of population management, and selection of the management units for optimizing exploitation, reproduction, and conservation of species fragments are discussed on the basis of this approach.