Topic 4

Question 1

Systematics

Answer 1

The theory snd practice of classifying organisms based on evolutionary history

Question 2

What are phylogenies inferred from?

Answer 2

Morphological and molecular data

Question 3

What is a phylogenetic tree?

Answer 3

A proposed hypothesis about evolutionary relationships among a set of organisms

Question 4

What is a Basal taxon?

Answer 4

A group that diverges early and originates near the common ancester

Question 5

Polytomy

Answer 5

A brance that diverges with more than two groups

Question 6

What is a clade

Answer 6

A piece of phylogenie that includes an ancestor and all descendants

Question 7

Difference between cladograms and phylograms

Answer 7

Cladogram - order of branching matters, evolutionary RELATIONSHIPS
Phylogram - length of branches matters, length demonstrates a timeline, evolutionary PATTERNS

Question 8

When two species share a recent common ancestor, what could this indicate?

Answer 8

The two species are closely related

Question 9

Phylogenetic trees show evolutionary ______, not progress

Answer 9

Relationships

Question 10

Do all clades have an assigned taxonomic rank?

Answer 10

No

Question 11

Convergent evolution

Answer 11

New traits form independantly due to adaptation

Question 12

What trait should only be used to contruct a phylogenetic tree?

Answer 12

Homologous

Question 13

Analogy is due to _____ evolution

Answer 13

Convergent

Question 14

Convergent evolution

Answer 14

Independant evolution of similar traits in different lineages

Question 15

Does convergent evolution provide information about shared evolutionary history?

Answer 15

No

Question 16

Homoplasy

Answer 16

Trait shared by a set of taxa, but absent in the common ancestor

Question 17

The more complex two similar structures are, the more likely that they are homologous

Answer 17

True

Question 18

Ingroup

Answer 18

Group of taxa that you are interested in studying

Question 19

Outgroup

Answer 19

One or more taxa that are related to the ingroup but diverge from the ingroup early in time

Question 20

Character vs. character state

Answer 20

Character: anatomical, physiological, molecular features

Character state: observed prescence/absence of a character
(Some organisms have lungs, some taxa dont)

Question 21

Monophyletic

Answer 21

A group that consists of an ancestor and all of its descendants

Question 22

Cladistics

Answer 22

A method of inferring phylogeny from homologous traits

Question 23

Paraphyletic groups

Answer 23

Groups with a common ancestor, but not all of their descendants are present

Question 24

How do paraphyletic groups arise?

Answer 24

When slightly higher divergent taxa are removed from their original clade

(Any group removed = paraphyletic)

Question 25

Polyphyletic group

Answer 25

Group that does not include the common ancestor, only includes descendants

Group is missing a common ancestor that unites the group

Question 26

What is a cause of polyphyletic grouping?

Answer 26

Incorrect taxanomic classification

Question 27

Synapomorphy

Answer 27

A shared derived character in a taxon shared by two or more taxa and their most recent common ancestor
But the trait is absent in the ancestor that precedes the clade

Question 28

Symplesiomorphy

Answer 28

Shared ancestral character shared by several groups, but inherited from ancestors older than the last common ancestor

Question 29

Can a characteristic be derived and ancestral in some cases?

Answer 29

Yes