Biology Chapter 20: Phylogenies and the History of Life

Flashcards based on Biology Chapter 20 lecture notes focusing on Phylogenies and the History of Life.

Phylogeny

Describes the evolutionary history and relationships among organisms.

Phylogenetic Tree

A diagram that represents evolutionary relationships.

Basal Taxon

A lineage that evolved early and remains unbranched on a phylogenetic tree.

Sister Taxa

Two lineages that stem from the same branch point on a phylogenetic tree.

Polytomy

A branch on a phylogenetic tree with more than two lineages.

Taxonomy

The science of classifying organisms using an international system.

Binomial Nomenclature

A two-word naming system using genus and species to identify an organism.

Homologous Traits

Similar structure but different function, indicating a common ancestor (divergent evolution).

Analogous Traits

Similar function but different structure, do not indicate a common ancestor (convergent evolution).

Cladistics

A system for grouping organisms by homologous traits to build phylogenetic trees.

Clade

A grouping of organisms that includes a common ancestor and all of its descendants.

Maximum Parsimony

The assumption that the simplest, most obvious order of events leads to the occurrence of new traits.

Horizontal Gene Transfer (HGT)

Gene transfer between unrelated species.