Sister Taxa

Definition

Sister taxa are two species that share the most recent common ancestor on a phylogenetic tree. They are closely related to each other and diverged from their common ancestor more recently than any other taxa present in the tree.

Related terms

Node: Nodes represent points on a phylogenetic tree where lineages split or diverge from each other, indicating speciation events.

Outgroup:

An outgroup is a taxon that is closely related to the group being studied but diverged from it earlier. It helps to determine the ancestral character states and root the phylogenetic tree.

Monophyletic Group: A monophyletic group, also known as a clade, consists of an ancestor and all of its descendants. Sister taxa are part of the same monophyletic group on a phylogenetic tree.