22 Phylogenetics and Systematics

These flashcards cover key terms and definitions related to phylogenetics and systematics, allowing for a better understanding of evolutionary relationships among organisms.

Phylogeny

A hypothesis of how taxa are evolutionarily related.

Monophyletic group

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

Polyphyletic group

A group that shares similar traits but does not include the most recent common ancestor.

Paraphyletic group

A group that includes an ancestral population and some of its descendants, but not all.

Taxonomics

The study of naming, describing, and classifying organisms.

Systematics

The study of the pattern of relationships among taxa; organization and categorization of all life that has ever existed.

Clade

A group of organisms that are more closely related to each other than to any taxon outside of the clade.

Node

Where branches split on a phylogenetic tree, representing a common ancestor.

Outgroup

A taxon that is outside of the clade being studied, used for comparative purposes.

Bacteria

Single-celled microorganisms that lack a nucleus and are classified as procaryotes.

Eukaryotes

Organisms whose cells have a nucleus enclosed within membranes, including animals, plants, fungi, and protists.

The Tree of Life

A metaphor that describes the relationships among various species, representing their evolutionary pathways.