Ch. 13 The Origin Of Species

Question 1

The distinction between “definition” and “recognition” is similar to the distinction between..

Answer 1

The formal description of a species and the diagnosis of a species

Question 2

Phenetic characters

Answer 2

All the observable or measureable characters of an organism, including microscopic and physiological

Question 3

Formal definition

Answer 3

Description of a species, using phenetic characters

Question 4

Phenetic species

Answer 4

Definition based on clustering of physical characters

Question 5

Typological species

Answer 5

Definition based on similarity to a type specimen or ideal type

Question 6

Reproductive species

Answer 6

Definition based on reproductive isolation

Question 7

Ecological species

Answer 7

Definition based on niche

Question 8

Non-temporal species concepts

Answer 8

Phenetic species
Typological species
Reproductive species
Ecological species

Question 9

Temporal species concepts

Answer 9

Cladistic species

Evolutionary species concept

Question 10

Cladistic species

Answer 10

Definition based on segment of phylogenetic tree

Question 11

Evolutionary species concept

Answer 11

Definition based on vague “tendencies”

Question 12

Biological species concept

Answer 12

• Species are groups of interbreeding populations that are reproductively isolated from other such groups
• Ernst Mayr
• most widely accepted definition for species
• species are unified by gene flow within a common gene pool

Question 13

Phylogenetic species concept

Answer 13

Smallest possible group descending from a common ancestor and recognizable by unique, derived traits

Question 14

Interbreeding between species is prevented by what?

Answer 14

Isolating mechanisms

Question 15

Isolating mechanisms

Answer 15

Serve to prevent interbreeding and thereby establish reproductive isolation of populations

Question 16

Isolating mechanisms can be categorized as either ___ or ___.

Answer 16

Premating (prezygotic)

Postmating (postzygotic)

Question 17

Premating isolating mechanisms prevent what?

Answer 17

Prevent mates from two separate populations from getting together

Question 18

The most basic of premechanisms involve one or another variation on ___

Answer 18

Allopatry

Question 19

Allopatry

Answer 19

Geographic separation, habitat separation, seasonal or temporal separation

Question 20

More complicated premating mechanisms involve..

Answer 20

Behavior, biomechanics, or gamete interaction to prevent gametes from coming together

Question 21

Geographic separation

Answer 21

Populations are geographically separated

Question 22

Habitat separation

Answer 22

Populations occur in different habitats in the same general region

Question 23

Seasonal or temporal separation

Answer 23

• mating or flowering occur in different seasons

- separation of photosynthesis and nitrogen fixing

Question 24

Cline

Answer 24

Gradual change in the species phenotype and genotype frequencies through a series of geographically separate populations

Question 25

Premating barriers

Answer 25

• timing of reproduction
• pollinator isolation
• mismatched morphology

Question 26

Gametic incompatibility

Answer 26

Sperm or pollen from one species fails to penetrate and fertilize the egg of another species

Question 27

Haldanes rule

Answer 27

In species with genetic sex determination, reduced viability or fertility is mucho more common in the heterogametic sex

Question 28

Postzygotic barriers

Answer 28

Hybrids are produced but have low fitness

• hybrid inviability
• hybrid sterility
• ecological inviability
• behavioral sterility

Question 29

recognition species concept

Answer 29

Species is defined by mutual recognition of suitable mates among the members of a population

Question 30

Ecological species concept

Answer 30

Places an emphasis on niche or adaptive zone

Question 31

Competitive exclusion

Answer 31

Two or more species cannot occupy the same niche

One is better and beats other out

Question 32

Character displacement

Answer 32

Similar species which share a common resource will diverge from one another

Question 33

Causes of speciation

Answer 33

• geographic isolation

- reduction of gene flow

Question 34

Allopatric speciation: the great divide

Answer 34

Allo = other
Patric = place
Speciation by geographic isolation

Question 35

Islands provide opportunity for ___ speciation

Answer 35

Allopatric

Question 36

Ring species

Answer 36

Populations at ends can no longer interbreed

Question 37

Peripatric speciation

Answer 37

Peri = near
Patric = place
A small population isolated at the edge of a larger population

Question 38

Sympatric speciation

Answer 38

Sym = same
Patric = place
New niche

Question 39

Parapatric speciation

Answer 39

Para = beside
Patric = place
Individuals are more likely to mate with their geographic neighbors than with individuals in a different part of the populations range

Question 40

Parapatric speciation begins with the evolution of a ..?

Answer 40

Hybrid zone

Question 41

Bacterial species often defined by what?

Answer 41

Specific adaptations

Question 42

Horizontal gene transfer makes ___ difficult

Answer 42

Classification

Question 43

General lineage species concept

Answer 43

Species are metapopulations that exchange alleles frequently enough to comprise the same gene pool