Phylogeny

These flashcards cover key vocabulary and concepts related to phylogenetics, including definitions of important terms and mechanisms involved in understanding evolutionary relationships.

Phylogeny

The evolutionary history of a species or group of related species.

Monophyletic

A group of taxa that includes a common ancestor and all its descendants.

Synapomorphy

A shared derived trait that evolved along an ancestral branch.

Sister Taxa

Groups that share a common ancestor that is not shared by any other group.

Outgroup

A taxon closely related to, but not part of, the group of species being studied (the ingroup).

Clade

A group of organisms that consists of a common ancestor and all of its descendants.

Node

The point on a phylogenetic tree where branches diverge, representing a speciation event.

Root

The base of a phylogenetic tree representing the most recent common ancestor of all taxa in the tree.

Operational Taxonomic Unit (OTU)

A singular taxon represented in a phylogenetic analysis.

Polyphyletic

A group that includes distantly related species but not their most recent common ancestor.

Paraphyletic

A group consisting of an ancestral species and some, but not all, of its descendants.

Molecular Clock

An approach used to estimate the absolute time of evolutionary change based on genetic mutations.

Binomial Nomenclature

A two-part naming system for species developed by Carolus Linnaeus.

Taxon

A group at any level of the hierarchical classification.

Hierarchical Classification

Linnaeus's system for grouping species into increasingly inclusive categories.