A new book on DNA genealogy shows the pattern of mutations on the Y chromosome of ancient human ancestors over hundreds of thousands of years, and shows how this pattern of mutations relates to human history. It is shown how these mutation patterns can be turned into chronological indicators, and ancient and relatively recent historical events can be dated in years, centuries, and millennia. At the same time, the chronometer that allows dating is not “external”; it is built into our DNA. Therefore, calculations in DNA genealogy are fundamentally protected from manipulation “from the outside,” just as, for example, the half-transformation times of radioactive elements in physics and chemistry are protected. No matter what you do, radioactive decay “ticks” in time, as it should according to physical laws. It’s the same in DNA genealogy – mutations “tick” according to the same laws, the fundamental patterns are the same. These laws are the methodological basis of DNA genealogy, and it, this basis, allows us to build the history of human development on all continents. So, the book shows DNA genealogy in haplogroups from A to T. In other words, the DNA genealogy of every male reader is described without exception, some almost literally, some from a bird’s eye view, and for it to turn out to be literal, you just need to do a test for haplogroups-subclades and haplotypes. Who is this book for? For those who want to understand their history and their ancestors, and how this personal history is built into the history of their ethnic group, country, and all humanity.