Chapter 20 Flashcards
Similarity between two species that is due to convergent evolution rather than to descent from a common ancestor with the same trait
Analogy
And I specified group of organisms, a taxon whose evolutionary lineage derived early in the history of the group
Basal taxon
A common term for the two-part, Latin Nised format for naming a species, consisting of The genus and specific epithet; also called a binomen
Binomial
The representation on a phylogenetic tree of the divergence of two or more taxa from a common ancestor. A blank is usually shown as a dichotomy in which a branch representing the ancestral lineage splits into two branches, one for each of the two descendent lending edges
Branch point
A group of species that includes an ancestral species and all of its descendants
Clade
An approach to systematics in which organisms are placed into groups called clades based primarily on common descent
Cladistics
In Linnaean classification, the taxonomic category above the level of order
Class
(1) A taxonomic category above the kingdom level. The three blanks are Archaea, bacteria and eukarya
Domain
In Linnaean classification, the taxonomic category above genus
Family
A taxonomic category above the species level, designated by the first word of a species two-part scientific name
Genus
A similar structure or molecular sequence that has evolved independently and two species
Homoplasy
The transfer of genes from one genome to another through mechanisms such as transposable elements, plasma exchange, viral activity, and perhaps fusions of different organisms
Horizontal gene transfer
A species or group of species whose evolutionarily relationships are being examined in a given analysis
Ingroup 
A taxonomic category, the second broadest after domain
Kingdom
A principle that states that when considering multiple explanation for an observation, one should first investigate the simplest explanation that is consistent with the facts
Maximum parsimony
A method for estimating the time required for a given amount of evolutionary change, based on the observation that some regions of genomes evolve at constant rates
Molecular clock
Pertaining to a group of taxa that consist of a common ancestor and all of its descendants. A blank taxon is equivalent to a clade
Monophyletic
In Linnaean classification, the taxonomic category above the level of family
Order
A species or group of species from an evolutionarily lineage that is known to have diverge before the lineage that contains the group of species being studied. A blank is selected so that its members are closely related to the group of species being studied, but not as closely related as any study group members are to each other
Outgroup
Pertaining to a group of taxa that consist of a common ancestor and some, but not all, of its descendants
Paraphyletic
A branching system that represents a hypothesis about the evolutionarily history of a group of organisms
Phylogenetic tree
The evolutionarily history of a species or group of related species
Phylogeny
And Linnaean classification, the taxonomic category above class
Phylum
Pertaining to a group of taxa that includes distantly related organisms but does not include their most recent common ancestor
Polyphyletic
In a phylogenic tree, a branch point from which more than two descendent taxa emerge. A blank indicates that the evolutionarily relationships between the descendent taxa or not yet clear
Polytomy
Describing a phylogenetic tree that contains a branch point (Often, the one farthest to the left) representing the most recent common ancestor of all taxa in the tree
Rooted
Character that is shared by members of a particular clade but that originated in an ancestor that is not a member of that clade
Shared ancestral character
An evolutionary novelty that is unique to a particular clade
Shared derived character
Groups of organisms that share an immediate common ancestor and hence are each other’s closest relatives
Sister taxa
A scientific discipline focused on classifying organisms and determining the revolutionary relationships
Systematics
A named taxonomic unit at any given level of classification
Taxon
A scientific discipline concerned with naming and classifying the diverse forms of life
Taxonomy
