Population Genetic Structure: Where, What, and Why?

Biodiversity is crucial for humankind. It encompasses three main levels: ecosystem, species, and intraspecific genetic diversity. Species consist of populations that exhibit deoxyribonucleic acid (DNA) variability, which is a key component of intraspecific genetic diversity. In turn, intraspecific genetic diversity is directly linked with the term population genetic structure (PGS). There is a great deal of uncertainty and confusion surrounding the concept of the PGS of species in the scientific literature, yet the term PGS is central to population genetics, and future research is expected to focus on the evolutionary continuum from populations to species. Therefore, it is necessary for current biologists and the next generation of scientists to acquire a better understanding of a PGS, both as a term and a concept, as well as the various roles PGSs play within a biodiversity context. This knowledge can then be applied to the expansion of both practical and theoretical science. Finding answers and reaching a consensus among the scientific community on certain questions regarding PGSs could expand the horizons of population genetics and related research disciplines. The major areas of interest and research are PGSs’ roles in the processes of microevolution and speciation, the sustainable use of natural resources, and the conservation of genetic diversity. Other important aspects of this perspective review include proposals for scientific definitions of some terms and concepts, as well as new perspectives and explanations that could be used as a basis for future theoretical models and applied research on PGSs. In conclusion, a PGS should be viewed as a fragile genetic mosaic encompassing at least three spatial dimensions and one temporal dimension.