Basal taxon

Definition

A basal taxon is a lineage that diverges early in the history of a group and remains unbranched. It is often used as a reference point to understand evolutionary relationships within a clade.

5 Must Know Facts For Your Next Test

1. A basal taxon appears at the base of a phylogenetic tree.
2. Basal taxa are important for understanding the ancestral traits of a group.
3. They help illustrate how different lineages have evolved over time.
4. A basal taxon does not imply primitiveness but indicates an early branch in evolutionary history.
5. Outgroup species are often chosen from basal taxa to root phylogenetic trees.

Review Questions

Related terms

clade: A group of organisms believed to have evolved from a common ancestor, according to the principles of cladistics.

outgroup: A species or group that is closely related to the ingroup but not part of it, used as a reference point in phylogenetic analysis.

phylogenetic tree:

A branching diagram showing the inferred evolutionary relationships among various biological species based upon similarities and differences in their physical or genetic characteristics.