The book "Maximum Possible ." Correspondence F. G. Dobzhansky with domestic biologists: 1920-1970. Part 1" is a unique edition that opens the curtain for readers over the most important moments in the history of Russian biology and science in general. This collection contains letters and correspondence of the outstanding geneticist and evolutionist F. G. Dobrzhansky and his colleagues, which allows a deeper understanding of not only scientific ideas, but also personal relationships that were formed during this difficult time. Fedor Grigoryevich Dobzhansky - a figure, of course, a landmark for 20th century biology. His work became the basis for many areas in genetics and evolutionary theory. The book contains letters that cover the period from 1920 to 1970, which allows us to trace the evolution of scientific views and approaches to the study of wildlife in the context of political and social changes. The reader will be able to see how Dobzhansky interacted with domestic scientists, shared his discoveries and discussed topical issues of science. This book will be of interest not only to professional biologists and historians of science, but also to a wide range of readers interested in the history of Russia, culture and science. Students, graduate students and teachers will find valuable materials for their research in it, and lovers of history and science will be able to immerse themselves in the atmosphere of scientific discussions and discoveries that took place in the country at that time. The book will also attract the attention of those interested in the personalities behind the great discoveries and how their ideas were shaped in the context of time. The themes raised in the book are diverse and multi-faceted. It addresses issues of genetics, evolution, as well as the social and political aspects of scientific activity. Readers will be able to see how scientific theories and ideas have been challenged, developed and adapted in a changing world. Dobzhansky's correspondence with domestic scientists reflects not only scientific debate, but also personal experiences, hopes and disappointments, which makes the text especially lively and emotional. The style of the authors who collected and prepared this correspondence is characterized by deep analyticalness and attention to detail. They not only represent facts, but also create a context in which these facts make sense. This allows the reader not only to