(2) Vocab: Phylogeny and the Tree of Life

Taxonomy

Ordered division of naming organisms

Phylogeny

Evolutionary history of a species or group of related species

Systematics

Scientific discipline of classifying organisms and determining their evolutionary relationships

Taxonomic Groups from broad to narrow:

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

The various taxonomic levels (genera, classes, etc.) of the

hierarchical classification system differ from each other on the

basis of

A) how widely the organisms assigned to each are distributed

throughout the environment.

B) their inclusiveness.

C) the relative genome sizes of the organisms assigned to each.

D) morphological characters that are applicable to all organisms.

Phylogenetic Tree

A hypothesis about the evolutionary relationships between taxa

Based on this tree, which statement is NOT correct?

A) The salamander lineage is a basal taxon.

B) Salamanders are a sister taxon to the taxon containing lizards, goats, and humans.

C) Salamanders are as closely related to goats as they are to humans.

D) Lizards are more closely related to salamanders than to humans.

Cladistics

Approach for constructing phylogenetic trees using shared characters and inferred common ancestry

Clade

Group of species that includes an ancestral species and all its descendants

Shared ancestral character

Character that originated in an ancestor prior to the clade of interest (ancestral state)

Shared derived character

Character that is noveau to a particular clade (synapomorphy)

Ingroup

Species or group of species being studied in a phylogenetic analysis

Outgroup

Species or group of species that is closely related to the in-group, but diverged before the in-group

Parsimony

Assumes fewest evolutionary changes over time

Maximum Likelihood

Includes likelihood. of certain types of mutations and changes

Molecular Clock

Using constant rates of mutation to estimate divergence of times