50 years of DNA double helix; what was before, and afterwards The present book, although written mainly for science students and research scientists, is also aimed at those readers who look at science, not for its own sake, but in search of a better understanding of our world in general. What were the fundamental questions asked by the early pioneers of molecular biology? What made them tick for decades, trying to elucidate the basic mechanisms of heredity and life itself? In each chapter, the development of a particular aspect of modern biology is described in a historical and logical context, not missing to take into account human aspects of the protagonists of the story. At the end of each chapter, there are some excursus with additional information, technical and otherwise, which can be read separately. The book is enriched with many illustrations, including facsimile reproductions from the original descriptions of key experiments.