Chapter 21: Species and Speciation

Question 1

_________ is the key to the biological species concept

Answer 1

reproductive isolation

Question 2

Species plot

Answer 2

a graphical representation of traits of individuals

Question 3

Biological Species Concept

Answer 3

species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups

Question 4

hybridization

Answer 4

closely related species can reproduce

Question 5

Wallace Effect

Answer 5

there should be selection against hybridization

Question 6

Ring species

Answer 6

some populations are isolated, others are not

Question 7

Ecological Species Concept

Answer 7

sometimes the ecology of a species should be what defines a species

Question 8

Phylogenetic species concept

Answer 8

the idea that members of a species all share a common ancestry and fate

Question 9

_________ ________ is caused by barriers to reproduction before and after

Answer 9

reproductive isolation

Question 10

What are the 4 pre-zygotic reproductive barriers?

Answer 10

behavioral, physical, temporal, ecological

Question 11

What are the 2 post-zygotic reproductive barriers?

Answer 11

genetic incompatibility leading to failure of the zygote to develop; sterile offspring

Question 12

________ underlies the diversity of life on Earth

Answer 12

speciation

Question 13

Allopatric

Answer 13

geographically separated from each other

Question 14

Vicariance-derived speciation

Answer 14

a change in the physical environment that causes allopatry (random even)

Question 15

Peripatric Speciation

Answer 15

a specific kind of allopatric speciation in which a few individuals from a mainland population disperse to a new location remote from the original population and evolve separately

Question 16

adaptive radiation

Answer 16

speciation occurs quickly and a variety of ecologically distinct forms are generated as the organisms adapt to local conditions successfully

Question 17

What are two kinds of allopatric speciation?

Answer 17

adaptive radiation and peripatric speciation

Question 18

co-speciation

Answer 18

when organisms speciate in response to each other; one changes a bit and the other one changes in response to the first (ex. lice and hosts)

Question 19

sympatric speciation

Answer 19

describes populations that are in the same geographic location; usually a result of disruptive speciation

Question 20

Can speciation occur without natural selection?

Answer 20

Yes

Question 21

What is a type of instantaneous speciation?

Answer 21

polyploidy

Question 22

instantaneous speciation

Answer 22

speciation that occurs within a single generation

Question 23

Like hybridization, ______ produced offspring who cannot reproduce with the parent generation

Answer 23

polyploidy

Question 24

True or False: selection always leads to speciation

Answer 24

false

Question 25

genetic drift

Answer 25

occurs when unpredictable variations change the structure of the gene pool (has less effect on large populations)

Question 26

Sympatric speciation is associated with what type of selection

Answer 26

disruptive

Question 27

Allopatric speciation is facilitated by ____ _____

Answer 27

natural selection

Question 28

Natural selection favors ______ isolation

Answer 28

pre-zygotic

Question 29

speciation

Answer 29

the process that produces new and distinct forms of life