Key Terms – Organization of Life
- analogous structure
- a character found in two taxa that looks similar because of convergent evolution, not because of descent from a common ancestor
- binomial nomenclature
- a system of two-part scientific names for an organism, which includes genus and species names
- branch point
- a point on a phylogenetic tree where a single lineage splits to distinct new ones
- clade
- a group of taxa with the same set of shared derived characters, including an ancestral species and all its descendants
- cladistics
- a method used to organize homologous traits to describe phylogenies using common descendent as the primary criterion used to classify organisms
- class
- the category in the taxonomic classification system that falls within phylum and includes orders
- domain
- the highest level category in the classification system and that includes all taxonomic classifications below it; it is the most inclusive taxon
- family
- the category in the taxonomic classification system that falls within order and includes genera
- genus
- the category in the taxonomic classification system that falls within family and includes species; the first part of the scientific name
- kingdom
- the category in the taxonomic classification system that falls within domain and includes phyla
- maximum parsimony
- applying the simplest, most obvious way with the least number of steps
- molecular systematics
- the methods of using molecular evidence to identify phylogenetic relationships
- monophyletic group
- (also, clade) organisms that share a single ancestor
- order
- the category in the taxonomic classification system that falls within class and includes families
- phylogenetic tree
- diagram used to reflect the evolutionary relationships between organisms or groups of organisms
- phylogeny
- evolutionary history and relationship of an organism or group of organisms
- phylum
- the category in the taxonomic classification system that falls within kingdom and includes classes
- rooted
- describing a phylogenetic tree with a single ancestral lineage to which all organisms represented in the diagram relate
- shared ancestral character
- a character on a phylogenetic branch that is shared by a particular clade
- shared derived character
- a character on a phylogenetic tree that is shared only by a certain clade of organisms
- sister taxa
- two lineages that diverged from the same branch point
- species
- the most specific category of classification
- systematics
- the science of determining the evolutionary relationships of organisms
- taxon
- a single level in the taxonomic classification system
- taxonomy
- the science of classifying organisms