Chapter 20: Phylogenies

What is systematics?

Study of biodiversity to understand evolutionary relationships.

What is taxonomy?

Branch of systematics that assigns organisms to categories (taxa).

What is classification?

Naming and assigning organisms to a taxon.

What is phylogeny?

Reconstruction of the evolutionary history of organisms.It illustrates relationships based on common ancestry.

In binomial nomenclature, what do the two parts represent?

Genus name (capitalized) + species name (lowercase), both italicized.

What are the three domains of life?

A: Bacteria, Archaea, Eukarya.

Which domains include prokaryotes?

Bacteria and Archaea.

What are the four kingdoms in Domain Eukarya?

Protista, Plantae, Fungi, Animalia.

Put the Linnaean classification in order (least → most specific):

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

What is a shared ancestral trait?

Trait present in the common ancestor and all its descendants.

What is a shared derived trait?

Trait unique to a specific lineage, not present in the common ancestor.

What is a clade?

A common ancestor and all its descendants.

In a cladogram, what is the ingroup?

The group of taxa being studied.

What is the outgroup in a cladogram?

A taxon outside the ingroup used for comparison.

How do you identify a derived trait?

Present in ingroup but not outgroup.

What are the sources of traits for constructing a cladogram?

Fossil traits, morphological traits, behavioral traits, molecular traits.

What is a molecular clock?

Uses neutral mutations accumulating at a constant rate to estimate evolutionary timelines.