Ch. 20 - Phylogeny Flashcards
What is phylogeny?
The evolutionary history of species alive today
What is systematics?
A discipline focused on classifying organisms and determining their evolutionary relationships
what is taxonomy?
how organisms are named and classified
what is the arrangement of hierarchical classification?
species, genus, family, order, class, phylum, kingdom, domain
what is a taxon?
a taxonomic unit at any level of the hierarchy
what is a phylogenic tree?
a representation of evolutionary history of a group of organisms
what is a branch point?
a representation of the divergence of two evolutionary lineages from a common ancestor
what are sister taxa?
groups of organisms that share an immediate common ancestor
what does rooted mean?
that a branch point within the tree represents the most recent common ancestor of all taxa in the tree
what is a basal taxon?
a linage that diverges early in the history of a group bend
what is polytomy?
a branch point from which more than two descendant groups emerge
what are phylogenetic trees based off of?
patterns of descent, NOT phenotypic similarities
what is cladistics?
systematics in which common ancestry is the primary criterion used to classify organisms
what is a clade?
a group of species that includes an ancestral species and all of its descendants
monophyletic
consists of an ancestral species and all of its descendants
paraphyletic
consists of an ancestral species and some of its descendants
polyphyletic
includes taxa with different ancestors
shared ancestral character
a characteristic that originated in an ancestor of the taxon