Lab 9 - Phylogeny

Question 1

Morphological (Phenotypic) Data

Answer 1

Comparative Anatomy
Extinct or Extant Taxa
Limited and subjective

Question 2

Molecular Data

Answer 2

DNA
Extant Taxa Only
Not subjective
Could be errors to mutations

Question 3

What is a character matrix?

Answer 3

A table listing organisms and their traits, used to determine evolutionary relationships.

Question 4

What is a common ancestor?

Answer 4

An extinct species from which two or more descendant species evolved.

Question 5

What are ancestral traits (plesiomorphies)?

Answer 5

Older traits inherited from a distant ancestor; shared broadly across groups.

Question 6

What are derived traits (apomorphies)?

Answer 6

Newer, evolved traits unique to a particular lineage.

Question 7

What is an outgroup?

Answer 7

A taxon with an evolutionary lineage that has diverged from the rest
of the taxa in the cladogram or phylogenetic tree.

Question 8

What do branches on a cladogram represent?

Answer 8

Evolutionary lineages over time.

Question 9

What do internal nodes represent?

Answer 9

A hypothetical common ancestor from which two separate
evolutionary lineages have diverged.

Question 9

What is a clade?

Answer 9

A group of organisms that have evolved from a common ancestor.

Question 10

What do terminal nodes (tips) represent?

Answer 10

Individual groups of organisms (taxa) with their own
independent evolutionary lineage.

Question 11

What are sister taxa?

Answer 11

Two taxa that share the most recent common ancestor; each other’s closest relatives.

Question 12

Parsimony

Answer 12

the simplest explanation to a problem is the most likely answer.

Question 13

Parsimony in phylogenetics

Answer 13

traits are more likely to arise
once and be passed down from a common ancestor than for multiple groups of organisms to develop the same trait separately.