Paraphyletic

Definition

A taxonomic group that includes some but not all the descendants of a common ancestor.

Etymology

From Greek 'para-', meaning 'beside' or 'apart', and 'phyletic', referring to lineage.

Example

The group of insects known as Hemimetabolous is paraphyletic because it excludes the Holometabolan group, which shares a more recent common ancestor.

Related Terms

• Monophyletic
• Polyphyletic

Usage Notes

Paraphyletic groups are considered incomplete evolutionary units.