Systematics and the Origin of Species Ernst Mayr Cambridge, Massachusetts: Harvard University Press, 1942 About the Book One of Ernst Mayr's greatest and most influential books. This classic study helped to revolutionize evolutionary biology by offering a new approach to taxonomic principles and correlating the ideas and findings of modern systematics with those of other life science disciplines. This book is one of the foundational documents of the "Evolutionary Synthesis." It is the book in which Mayr pioneered his new concept of species based chiefly on such factors as interbreeding and reproductive isolation, taking into account ecology, geography and life history.