The paper discusses a methodology for studying one of the most complex phenomena in the organic world struggle for existence within the course Theory of Evolution at a pedagogical university. The study of information about the history of development and the formation of evolutionary concepts shows that the discovery of the factors of the organic world evolution is one of the outstanding achievements in the development of biology. In the 20th century, scientific knowledge about the causes of the evolutionary process expanded and together with the material factors of evolution discovered by Charles Darwin stand out as follows: mutation process, dynamics of the number of organisms, isolation, migration, struggle for existence and natural selection. The modern level of struggle for existence theory development is based on achievements in the field of ecology and evolutionary biology and proves that this factor of evolution really exists. The developed methodology for studying this topic includes the content of the course program, a list of questions for study, recommendations for laboratory studies and independent observations in nature. Since the course is studied in the 5th year, it relies on students knowledge from other biological courses as well as on the skills they develop. The course contains the use of elements of partial search and research methods (laboratory work, observations in nature) of teaching with options for conversation, comparison of different points of view, etc. The proposed variant of studying the Struggle for Existence topic will contribute to the high-quality training of students prospective teachers of biology.