The evolutionary history of a group of organisms especially as depicted in a family tree diagram showing the evolutionary interrelations of a group of organisms
derived from a common ancestral form. The ancestor is in the tree
“trunk”; organisms that have arisen from it are placed at the ends of
tree “branches.” The distance of one group from the other groups
indicates the degree of relationship; i.e., closely related
groups are located on branches close to one another. Phylogenetic trees,
although speculative, provide a convenient method for studying
phylogenetic relationships.
