Biology 26: Phylogeny

the evolutionary history of a species or group of related species

a discipline focused on classifying organisms and determining their evolutionary relationships

how organisms are named and classified by their characteristics

classification system in which each species is assigned a two-part scientific name

domain kingdom phylum class order family genus species

a taxonomic unit at any level of hierarchy

a branching diagram that represents the evolutionary history of a group of organisms

a classification system which recognizes only groups that include a common ancestor and all its descendants

represents the divergence of two evolutionary lineages from a common ancestor

groups of organisms that share an immediate common ancestor

phylogenetic tree that includes a branch to represent the last common ancestor of all taxa in the tree

a lineage that diverges early in the history of a group

a branch from which more than two groups emerge

phenotypic and genetic similarities due to shared ancestry

similarities due to convergent evolution

analogous structures or molecular sequences that evolved independently

discipline that uses DNA and other molecular data to determine evolutionary relationships

the approach to systematics in which common ancestry is the primary criterion used to classify organisms

a monophyletic group of species that includes an ancestral species and all its descendants

a non-clade group which consists of an ancestral species and some of its descendants

a non-clade group in which some members have different ancestors

a character that originated in an ancestor of the taxon

a character that is an evolutionary novelty unique to a particular clade

a species from an evolutionary lineage that is known to have diverged before the species we are studying

assumes that the tree that requires the fewest evolutionary events (simplest) is the most likely

given certain probability rules about how DNA sequences change over time, a tree can be found that reflects the most likely sequence of evolutionary events

the concept that some genes evolve at constant rates, and which is used to estimate the absolute time of evolutionary change

states that much evolutionary change in genes and proteins has no effect on fitness and therefore is not influenced by Darwinian selection

the movement of genes from one genome to another via transposable elements, plasmids, viruses, and fusion of organisms