theme 5ab Flashcards
what is taxonomy?
the science of identifying, naming, and classifying new species
what is binomial nomenclature?
a system in which species are given a two part Latinized name, where the first part identifies and genus and the second part identifies the specific epithet (species name)
what are all the groupings in the taxinomical hierarchy?
domain kingdom phylum class order family genus species
what is a taxon?
all the organisms within any category at any level of the taxinomical hierarchy (ex: all organisms within the class Mammalia are one taxon, and all organisms within the genus Ursus are a different taxon)
what is a phylogeny?
the evolutionary history of an organism/organisms
what is a phylogenetic tree?
branching diagrams that illustrate phylogenies. are formal hypotheses that identify likely relationships among species and higher taxonomic groups
what does the root of a phylogenetic tree represent?
the common ancestor of all the species represented in the tree
what is anagenesis?
pattern of evolution as gradual change
what is cladogenesis?
when one species undergoes speciation, producing two species distinct from each other and their common ancestor
do anagenesis and cladogensis increase biodiversity?
anagenesis does not but cladogenesis does
what are sister clades?
two clades that originate from the same node
what are sister species?
two species that emerge from the same node near the very top of the tree
what does it mean when more than two branches originate from a single node?
it indicates the biologists are not yet sure what the exact order and relationship of the branches is yet, these nodes are “unresolved”
what is a monophyletic taxon/lineage?
basically a clade. a portion of a tree that consists of an ancestral species and all of its descendants.
what is a polyphyletic taxon/lineage?
a taxa that includes organisms from different clades of a phylogenetic tree but not the common ancestor of the clades