Lab - Dichotomous Keys and Phylogenetic Trees

Question 1

dichotomous key

Answer 1

comprise simple yes/no, absent/present, or opposing traits list of questions that guide the user towards a final identification.

Question 2

Phylogenetic Relationships

Answer 2

characters that reveal common ancestry

Question 3

Phylogenetic tree

Answer 3

evolutionary history of a group of organisms can be represented as a branching diagram

Question 4

Homologies

Answer 4

characters that are similar to shared ancestry

Question 5

Convergent Evolution

Answer 5

similar environmental pressures and natural selection produce similar(analogous) adaptations.

Not common ancestor.

Question 6

Homoplastic

Answer 6

Analogous

Question 7

Congruent

Answer 7

different kinds of characters(DNA v Morphology) produce similar datasets

Question 8

Parsimony

Answer 8

choosing alternative tree branching arragements(topology) and recognize which kinds of characters are phylogenetically informative.

Question 9

Clades

Answer 9

monophyletic groups

groups that contain an ancestral species and all of its descendents

Question 10

Synapomorphies

Answer 10

shared derived characters

Question 11

Outgroup

Answer 11

ancestral group

assume all characters are ancestral

Question 12

Polytomies

Answer 12

branches with 3 or more paths

Question 13

Parsimony

Answer 13

cladistic methods to make the assumption that the most likely tree is the one which requires the fewest evolutionary events

Question 14

Synapomorphic

Answer 14

character or trait derived by common ancestry

Question 15

Autapomorphy

Answer 15

character or trait which is derived but not shared