Current biological problems of a fundamental and applied nature are considered. The first part of the book introduces the reader to the circle of the most general ideas about populations, species and evolution. The second is devoted to the analysis of evolutionary factors. The third examines genetic polymorphism and its maintenance mechanisms. The fourth examines the most controversial mechanisms of biological and prebiological evolution. The fifth part is devoted to the issues of domestication, selection and the evolutionary consequences of fishing. Auxiliary material is included in Appendix. For evolutionists, ecologists, geneticists, breeders, veterinarians and conservationists. The book can be used by students, graduate students and university teachers in the educational process.