Lecture 12 - Phylogenetic Systematics

Question 1

What is phylogeny?

Answer 1

the evolutionary history of a species or groups of related species

Question 2

What is taxonomy?

Answer 2

the science of naming and classifying organisms

Question 3

What is systematics?

Answer 3

scientific system for classifying organsims

Question 4

What are phylogenetic systematics?

Answer 4

classification of organisms by their order of branching on an evolutionary tree

Question 5

Who developed old-school taxonomy?

Answer 5

Carolus Linnaeus

Question 6

What are the two parts for scientific naming?

Answer 6

1. binomial nomenclature

2. hierarchical classification system

Question 7

What has been added to the two part naming system?

Answer 7

Domain

Question 8

What are the 7 levels of the hierarchical classification system?

Answer 8

(domain)
kingdom
phylum
class 
order
family
genus
species
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Question 9

Why have old-school Linnaean categories been criticized?

Answer 9

do not always form monophyletic groups

Question 10

The class Reptilia is _______

Answer 10

paraphyletic

Question 11

Invertebrates are ____

Answer 11

paraphyletic

Question 12

Homeotherms are ________

Answer 12

polyphyletic

Question 13

What is PhyloCode?

Answer 13

-proposed classification system

Question 14

How does PhyloCode work?

Answer 14

• only monophyletic groups would be recognized
• most species names would remain unchanged
• use traditional taxonomic ranks

Question 15

What is a node?

Answer 15

where the lineages diverge

Question 16

What are sister taxa?

Answer 16

• most closely related groups

- groups of organisms that share an immediate common ancestor

Question 17

What is the basal taxon?

Answer 17

one that branches off the earliest

Question 18

What is polytomy?

Answer 18

an unresolved point of divergence

Question 19

What are branches rotated around?

Answer 19

nodes

Question 20

Phylogenies are inferred form ______ not _________

Answer 20

homologous characters not analogous characters

Question 21

What are homologous characters?

Answer 21

common ancestors

Question 22

What are analogous characters?

Answer 22

similar selective environments

Question 23

What are homoplasies?

Answer 23

analogous structures or molecular sequences that evolved interdependenty

Question 24

What is cladistics?

Answer 24

one approach to reconstructing phylogeny

Question 25

Cladistics groups species into ______

Answer 25

clades

Question 26

What are clades?

Answer 26

ancestor and all its descendents

Question 27

What does cladistics focus on?

Answer 27

shared, derived characters

Question 28

What principles does cladistics use?

Answer 28

1. parsimony

2. maximum likelihood

Question 29

What is outgroup comparison?

Answer 29

distinguishes between ancestral and derived characters

Question 30

What is an outgroup?

Answer 30

species/group from an evolutionary lineage that is known to have diverged before the lineage that includes the species we are studying

Question 31

What happens in maximum parsimony?

Answer 31

the best tree requires the fewest changes

Question 32

What is maximum likelihood?

Answer 32

alternative approach to reconstructing phylogeny

Question 33

What happens in maximum likelihood?

Answer 33

the best tree is the tree with the highest likelihood given certain rules about how DNA changes over time
-more computationally intensive

Question 34

What is a monophyletic group?

Answer 34

a common ancestor and all its descendents

Question 35

What is a paraphyletic group?

Answer 35

a common ancestor and some of its descendants

Question 36

What is a polyphyletic group?

Answer 36

a common ancestor is not present, but some descendants are

Question 37

What is an example of real-world parsimony?

Answer 37

four chambered hearts in birds/mammals