Lab Chapter 5

Question 1

Phylogenetic systematics

Answer 1

the study of evolutionary relationships among organisms using shared derived characters (Willi Henning 1950s)

Question 2

systematics

Answer 2

the study of the diversity of organisms

Question 3

taxonomy

Answer 3

the theory and practice of ordering the diversity of life into a classification system that reflects relationships among organisms

Question 4

Phylogenetic systematics is…

Answer 4

1. quantitative
2. reproducible
3. testable by the scientific method

Question 5

Phylogenetic systematics 3 assumptions

Answer 5

1. evolution occurs
2. there is a single phylogeny of life (as a result of evolutionary decent)
3. characters are passed down from generation to generation (modified- derived or unmodified-ancestral)

Question 6

Character site

Answer 6

character may be passed on from an ancestor to its descendant unmodified (ancestral) or modified (derived or shared derived if more than 1 taxon)

Question 7

( Character must be ) Homologous

Answer 7

characters in 2 or more species are derived from the same structure in a common ancestor

Question 8

homoplasy

caused by convergent evolution

Answer 8

character evolves more than once and it occurs in one species that is not in their common ancestor (MOST LIKELY CAUSED BY CONVERGENT EVOLUTION)

Question 9

homoplasy

caused by character reversal

Answer 9

species re-evolves the ancestral characer state

Question 10

How to determine if homoplasy is caused by character reversal or convergent evolution

Answer 10

whichever tree has least amount of transitions

Question 11

outgroup comparison method assumptions

Answer 11

1) any homologous character state found in the outgroup and in the ingroup is considered ancestral (always “0”) for the ingroup
2) character states found in the ingroup and not the outgroup are considered derived (“1” or more) for the ingroup