How clade help to define pattern of relationship in a phylogenetic trees

In phylogenetics, a clade is a group of organisms that includes an ancestor and all of its descendants, representing a single branch on the tree of life. This concept is central to the field of cladistics, a method of classification based on common ancestry. Clades are defined by their possession of shared derived characteristics (synapomorphies) that distinguish them from other groups. The members of a clade share a more recent common ancestor with one another than with any organisms outside the clade, making it a monophyletic group. Clades can vary in size from a large group that includes many species to a small group consisting of a single species and its descendants. Identifying and studying clades helps scientists understand the evolutionary relationships and history of life on Earth.