The Tree of Life: Phylogeny and Phylogenetic Trees

These flashcards cover key concepts related to phylogeny and phylogenetic trees, including definitions of important terms and distinctions between different types of groups.

Phylogeny

The evolutionary history of a lineage or lineages including populations, genes, or species.

Phylogenetic tree

A visual representation of phylogeny.

Outgroup

A species that’s more distantly related to the species of interest than they are to one another, acting as a proxy for the ancestral species.

Node

Represents common ancestors for all descendant lineages in a phylogenetic tree.

Clade

A common ancestor and all of its descendants.

Rooted tree

A phylogenetic tree that contains a common ancestor to all taxa within the tree.

Unrooted tree

A phylogenetic tree that does not show a common ancestor.

Internal node

A node that occurs within a phylogeny and represents ancestral populations or species.

Monophyletic group

A group consisting of a common ancestor and all its descendants.

Polyphyletic group

A group that does not share an immediate common ancestor, consisting of species descended from multiple ancestral lines.

Paraphyletic group

A group that shares a common ancestor, but does not include all the descendants of that ancestor.

Tip

The terminal end of an evolutionary tree representing the most recent species.