Please note that the content of this book mainly consists of articles that are available from Wikipedia or other free sources online. The Adam of the Y chromosome is a term from archaeogenetics for that prehistoric man who is related to all men living at a certain later point in time through an unbroken line of exclusively male descendants. An Adam of the Y chromosome is thus the common ancestor of all men living at a specific time, reconstructed by defining descent exclusively through fathers and male ancestors (patrilinearity), completely disregarding mothers and female ancestors, and selecting the genealogically youngest among several common ancestors identified under this condition.