Chapter 26, Phylogeny Flashcards
Define phylogeny
The (current hypothesis of the) evolutionary history of a species or group of related species
Define systematics
The classification of organisms and their evolutionary relationships
Define taxonomy
The scientific discipline concerned with classifying and naming organisms
Describe the two-part naming system for species
The name is called the binomial, the first part is the genus and the second part, the epithet is unique for each species
The first letter of the genus is capitalized and the entire species name is italicized
Name the eight taxonomic groups from broad to narrow
Domain, kingdom, phylum, class, order, family, genus, species
What is a taxon?
A taxonomic unit at any level of hierarachy
What are the three domains?
Bacteria, Archean, Eukaryota
Define phylogenetic tree
The evolutionary history of a group of organisms
What do branch points on a phylogenetic tree represent?
The divergence of two species
Define sister taxa
Groups that share an immediate common ancestor
Define a polytomy
An unresolved pattern of divergence in a phylogenetic tree
Define homology and give an example
Similarity due to shared ancestry- bones in whale flippers, bat wings, and human hands
Define analogy and give an example
Similarity due to convergent evolution, the Australian marsupial mole and the North American eutherian mole
Define cladistics
The grouping of organisms by common ancestry
Define clade
A group of species that includes an ancestral species and all its descendants
Define a monophyletic clade
Consisting of the ancestor species and all its descendants
Define a paraphyletic clade
Consisting of an ancestral species and some, but not all, of the descendants
Define a polyphyletic clade
Includes distantly related species but does not include their most recent common ancestor
Define shared ancestral character and give some examples
A character that originated in an ancestor of the taxon (distinguishes that clade from sisters)
Ex: milk and hair in mammals, four limbs in birds and mammals
Shared with the species ancestral to more than one group
Define shared derived character
A character that is an evolutionary novelty unique to a particular clade
Shared by the ancestral species and a single group
(unique to a clade), mutation in ancestor
Define ingroup and outgroup
An outgroup is a species or group of species that is closely related to the ingroup, the various species being studied
The outgroup diverged before the ingroup
What is another name for a Basal taxa?
Outgroup
