PHYLOGENETICS I

Phylogenetics

The study of evolutionary relationships among species.

Phylogeny

Another name for an evolutionary tree.

Taxonomy

The field of study that focuses on naming species.

Monophyletic

A group that contains all of the descendants of the group’s most recent common ancestor.

Paraphyletic

An ancestor and some of its descendants.

Polyphyletic

A group that includes distantly related species without including the most recent common ancestor.

Clade

A group that is monophyletic by definition.

Polytomy

A branching pattern with more than two descendants, indicating ambiguity in evolutionary relationships.

Rooted tree

A phylogenetic tree that includes the concept of time.

Unrooted tree

A phylogenetic tree that does not include the concept of time.

Branch length

Indicates genetic change or chronological time in a phylogenetic tree.

Natural selection

A mechanism of evolution that differs from other ideas about evolutionary processes.