AP Bio Unit 7.9 Phylogeny and Systematics

Vocabulary flashcards covering key terms and concepts related to phylogeny and systematics.

Phylogeny

The evolutionary history of a group of organisms.

Systematics

The classification of organisms and determining their evolutionary relationships.

Taxonomy

The science of naming and classifying species.

Phylogenetics

The hypothesis of evolutionary history, often represented through phylogenetic trees.

Phylogenetic Trees

Diagrams that represent the evolutionary history of a group of organisms, showing the amount of change over time.

Cladograms

A diagram that shows relationships among species, with each line representing a lineage and branching points as nodes.

Node

A point in a phylogenetic tree where a lineage splits, representing a common ancestor.

Clade

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

Sister Taxa

Two clades that emerge from the same node.

Basal Taxon

A lineage that evolved from the root and remains unbranched.

Synapomorphy

A derived character shared by clade members.

Derived Characteristic

Similarity inherited from the most recent common ancestor of an entire group.

Ancestral Characteristic

Similarity that arose prior to the common ancestor.

Outgroup

A lineage that is the least closely related to the rest of the organisms in a study.

Monophyletic Group

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

Paraphyletic Group

A group that includes the most recent common ancestor but not all its descendants.

Polyphyletic Group

A group that does not include the most recent common ancestor of all its members.

Principle of Parsimony

The hypothesis that requires the fewest assumptions is preferred when there are conflicts among characters.