Vert Zoo quiz 1 Flashcards
Define Taxon
Hierarchical categories used in taxonomy
What is a In group
group of interest in the cladogram
what is out group
reference group related to the organisms studied, but less closely related to any member of the in group than the in group members to each other
What is Monophyly
branch point that contains all the things that come from it
Principle of parsimony
favors the hypothesis that requires the fewest assumptions
What is convergent evolution
2 species independently evolve the same features
What is reversals
organism reverts back to an ancestral character
What are Homologous structures
characters that have descended from common ancestry
what is a sister group
most closely related descendants in a monophyletic group
Crown groups are…
extant species that have all the derived characters
Stem group are…
extinct forms that proceed the point at which the 1st member of the crown group branched off
Define clade
grouping of organisms that share a common ancestor
What is an ancestral trait
present in ancestor and passed down to decedents of the taxon
what is a derived trait
a newly developed trait, new characteristic feature which was absent in the ancestor
Define Synapomorphy
a derived trait, entire clade has the particular trait