Taxonomy, Phylogenetics, and Systematics Lecture Notes

This set of flashcards covers key terms and concepts discussed in the lecture on taxonomy, phylogeny, and systematics.

Systematics

The branch of biology related to discovering the evolutionary relationships among groups.

Phylogeny

A hypothesis about the evolutionary history of the relationships among groups.

Taxonomy

The branch of systematics focused on establishing classifications and naming organisms.

Clade

A group with a shared evolutionary history; a monophyletic group.

Monophyletic

A group that includes all descendants of a common ancestor; represents one unique evolutionary history.

Paraphyletic

A group that includes some but not all descendants of a common ancestor.

Polyphyletic

A group that includes members from more than one distinct evolutionary history.

Outgroup

A closely related group used to determine the ancestral state of characters in a character matrix.

Character Matrix

A table used to identify the presence or absence of traits across different taxa.

Homologous Traits

Traits shared by species that are derived from a common ancestor.

Rule of Parsimony

The principle that the simplest explanation or path is usually the correct one in phylogenetics.

Eukaryotic Cells

Cells with a nucleus and organelles, characteristic of plants and animals.

Sister Taxa

Two taxa that are each other's closest relatives on a phylogenetic tree.

Evolution

The process through which species change over time due to genetic variations and natural selection.

Character State

The specific version of a character found in an organism.

Ancestral State

The condition of a trait found prior to the divergence of a common ancestor.

Derived State

The condition of a trait found after the divergence from the common ancestor.