systematics,phylogeny and the tree of life Flashcards
what is phylogeny
the evolutionary history of a species
what is systematics
determining evolutionary relationships among organisms
what is the phenetic system
is groups organisms based on similarity of characteristics
what are the three systems used in systematics
phenetic,classic evolutionary & cladistic
why is the phenetic system unreliable
doesnt distinguish between homologous and analogous characteristics
what is the classic evolutionary system and cladistic system
both systems group organisms based on evolutionary relationships (characteristics)
however
classic looks at monophyletic and paraphyletic groups
cladistic looks at just monophyletic group
what is a paraphyletic group
a group of taxons (organisms) that contain ancestors but not descendants
what is a monophyletic group
a group of taxons (organisms) that contain ancestors and all descendants
what is a polyphyletic group
a group of taxons that contain descendants but not ancestors
what are the types of phylogenetic trees
cladogram
phylogram
dendrogram (ultrametric)
define what a phylogenetic tree is
a graphical representation of the evolutionary relationships between organisms
how do we add time to phylogenetic trees
radiometrics (comparing the of radioactive isotope with decayed products, stratigraphy (layering of rocks), molecular clocks (genetic difference)
