Читать книгу Principles of Microbial Diversity - James W. Brown - Страница 65

The root is the “base” of the tree—the last common ancestor of all of the organisms (or molecules) in the tree. It is not always possible to identify the root of a tree; typically, this requires either physical data (e.g., a fossil record) or data about organisms outside the part of the tree shown, i.e., an outgroup.