Lesson 5: Classification and Phylogeny Of Animals

Question 1

The practice of categorizing organisms according to similar features goes back to?

Answer 1

Aristotle

Question 2

The goal of Taxonomy today is to produce a formal system for naming and classifying species to?

Answer 2

To illustrate their evolutionary relationships

Question 3

• the taxonomist asks whether the species being classified contains the defining feature of a certain taxonomic group.
• Focus is on features

Answer 3

Classification

Question 4

• the taxonomist asks whether the characteristics of a species support the hypothesis that it descends from the most recent common ancestor of the taxonomic group.
• focus is on the evolutionary origin of those features.

Answer 4

Systematization

Question 5

He designed the hierarchical classification system in the 18th Century that is still in use today.

Answer 5

Carolus Linnaeus

Question 6

The major groups of organisms.

Answer 6

Taxa

Question 7

Singular form of Taxa

Answer 7

Taxon

Question 8

The system Carolus Linnaeus developed for naming species.

Answer 8

Binomial Nomenclature

Question 9

The two part scientific name includes

Answer 9

Genus and species

Question 10

The goal of ________ is to determine the ___________

Answer 10

Systematics, Phylogeny

Question 11

The evolutionary history of species or group of related species.

Answer 11

Phylogeny

Question 12

• Phylogenies are inferred by identifying organismal features, characters, that vary among species.
• These characters can be:

Answer 12

• Morphological (Physical)
• Chromosomal (DNA)
• Molecular (Cellular Level)
• Behaviour or Ecological
• Homology

Question 13

Shared characters that result from common ancestry.

Answer 13

Homologous characters

Question 14

• Shared characters that are not a result of common ancestry but of independent evolution of similar characters (not homologous).
• Can result from convergent evolution.

Answer 14

Homoplasies

Question 15

Occurs when natural selection, working under similar environmental pressures, produces similar (analogous) adaptations in organisms from different evolutionary lineages.

Answer 15

Convergent Evolution

Question 16

When trying to determine evolutionary relationship (inferring Phylogeny), we only want to consider ______________, because _______ can create errors.

Answer 16

Homologous Character, Homoplasies

Question 17

• Is a homologous structure that is older than the branching of a particular clade from other members of that clade.
• Shared by more than just the taxon we are trying to define.

Answer 17

Shared primitive character

Question 18

• A new evolutionary feature, unique to a particular group.
• These are the features that are most useful for determining evolutionary relationships.

Answer 18

Shared derived character

Question 19

• _______ is a form of character that was present in the common ancestor of the group.
• Variations of the character that arose later are called _______

Answer 19

Ancestral character state

Derived character states

Question 20

_______ (which version of that trait is ancestral) is determined by using outgroup comparison

Answer 20

Polarity

Question 21

Is closely related, but not part of the group being examined (ingroup).

Answer 21

Outgroup

Question 22

Found in both the study group and the outgroup.

Answer 22

Ancestral character

Question 23

Found in the study groups but not the outgroups.

Answer 23

Derived character

Question 24

Groups that share derived characters and form a subset within a larger group.

Answer 24

Clades

Question 25

Unit of common evolutionary descent.

Answer 25

Clade

Question 26

A derived character that is shared by all the members of the clade.

Answer 26

Synapomorphy

Question 27

Using ___________ to define clades will result in a ________

Answer 27

Synapomorphies, nested hierarchy of clades.

Question 28

Ancestral character states for a taxon are called ______

Answer 28

Plesiomorphic

Question 29

___________ are shared ancestral characters.

Answer 29

Symplesiomorphies

Question 30

Do not provide useful information for forming a nested series of clades.

Answer 30

Symplesiomorphies

Question 31

The nested hierarchy of clades can be shown as a _________ that is based on ____________.

Answer 31

Cladogram, Synapomorphies

Question 32

A valid clade that consists of the ancestor species and all its descendants.

Answer 32

Monophyletic

Question 33

A clade consists of an ancestral species and some, **but not all** of the descendants.

Answer 33

Paraphyletic

Question 34

A clade includes many species that lack a common ancestor.

Answer 34

Polyphyletic

Question 35

The two theories of Taxonomy

Answer 35

Cladistics and Evolutionary Taxonomy

Question 36

**Cladistics**, also called as ____________, is a taxonomic theory that is based on cladograms.

Answer 36

Phylogenetic Systematics

Question 37

All taxa must be...

Answer 37

Monophyletic

Question 38

- Based on common descent and the amount of evolutionary change to rank higher taxa. - Sometimes this type of classification includes **paraphyletic** groupings.

Answer 38

Traditional **Evolutionary Taxonomy**

Question 39

Humans, chimpanzees, gorillas, and orangutans are now all included together in one monophyletic family called _______

Answer 39

Hominidae

Question 40

Pair of Taxa that are most closely related to each other.

Answer 40

Sister Group

Question 41

What is the important difference between Cladistics and Evolutionary Taxonomy?

Answer 41

Traditional Evolutionary Taxonomy sometimes accepts *paraphyletic* ideas, while Cladistics does not.

Question 42

What are the similarities between Cladistics and Evolutionary Taxonomy?

Answer 42

- Both accept monophyletic clades. - Both reject polyphyletic clades