biology exam 1: chapter 20

binomial nomenclature for species

italics, genus capitalized

• ex: Felis sylvestris

taxonomy

grouping species together

• groups (taxa) based on similarities and differences

DKPCOFGS

Duh! - Domain

Keep - Kingdom

Pots - Phylum

Clean - Class
Or - Order

Family - Family

Gets - Genus

Sick - Species

phylogeny

the evolutionary history of a species & its relationship to other species

• shown as a “tree”

sister taxa

two branches grouped together

root

some commn ancestory way back

basal taxon

close to the root, very simple organisms

polytomy

a grouping of multiple, different branches

systematics

the study of phylogenetic relationships

• to create monophyletic taxa

monophyletic taxa

each taxon includes ancestor & all descendants

paraphyletic taxon

leaves out a common descendant

polyphyletic taxon

includes species with different ancestors

clade

an ancestor and all of its descendants

plesiomorphy

homologous characters shared with ancestor

• shared characteristics

synaptomophy

novel or evolved character different from ancestor

• evolved characteristic

dichotomous trees

• based on shared derived characters (synapomorphies)

principle of “maximum parsimony”

helps choose the best tree

• fewest evolutionary events