Phylogenies – Deciphering the Tree of Life

These flashcards cover key vocabulary terms and concepts related to phylogenies and the tree of life.

Phylogeny

The evolutionary history of a group of organisms.

Clade

A group of organisms that includes an ancestor and all of its descendants.

Monophyletic

A group that includes the most recent common ancestor and all its descendants.

Parsimony

A principle stating that the simplest explanation, requiring the fewest changes, is preferred.

Taxonomy

The hierarchical classification of species.

Binomial nomenclature

A system for naming species with two parts: the genus and the species name.

Sister taxa

Two taxa that are each other’s closest relatives.

Homologous features

Characteristics that are similar due to shared ancestry.

Analogous features

Characteristics that are similar due to convergent evolution, not shared ancestry.

Outgroup

A closely related group used as a reference point in building phylogenies.

Synapomorphies

Derived characters that are shared by a clade and are useful for determining evolutionary relationships.

Morphological characters

Features based on the form and structure of organisms.

Evolutionary reversal

The process where a character reverts from a derived state back to an ancestral state.

Homoplasy

A character state that has evolved independently in different lineages, complicating phylogenetic reconstruction.