The author tells about the animal world and the human kind. Only LUCA (Last Universal Common Ancestor) is not an apostle, but our common ancestor—and to understand what kind of creature it was, you, together with biologist Maksim Vinarский, will make a journey lasting more than 4 billion years. He will introduce you to the history and evolution of multicellular animals. He will explain that we, humans, are only one of the many branches of the great Tree of Life, and that the species Homo sapiens emerged according to laws common to the evolution of all living things. He will discuss how biologists identify relationships between animals and reconstruct the paths of their evolution. He will tell about the lives and scientific discoveries of scientists—those who came up with the idea of evolutionary relatedness of all organisms on Earth and figured out how to determine that relatedness.