Chapter 22

Question 1

what two things must be accounted to make up a species?

Answer 1

the distinctness at a single location
and
connections between different populations in the same species

Question 2

What is it called when species diverge in phenotypic and genetic traits within the same population?

Answer 2

Sympatric speciation

Question 3

What is an intervening population?

Answer 3

A population that has the traits of other populations in a different area within the same species.

Question 4

What are the pre-zygotic reproductive isolations?

Answer 4

Ecological isolation, behavioral isolation, temporal isolation, mechanical isolation, prevention of gamete fusion

Question 5

What are the post-zygotic reproductive isolations?

Answer 5

Hybrid inviability and hybrid infertility

Question 6

What is are the characteristics of a species according to the biological species concept?

Answer 6

The population has the possibility of interbreeding and must be reproductively isolated from other populations

Question 7

What is are the characteristics of a species according to the ecological species concept?

Answer 7

When the gene flow is weak, a species’ differences are stabilized through natural selection (process is called reinforcement)

Question 8

Can incomplete speciation and partial isolating reproduction exist?

Answer 8

Yes, some populations do not fully speciate, and some hybrids may be able to survive.

Question 9

What is pre-mating isolation?

Answer 9

When circumstances do not allow two populations to breed

Ex: Some butterflies only pollinate one color of flowers while other butterflies pollinate another color of the same flowers. Those two colors of flowers will not get a chance to breed together.

Question 10

Will reinforcement ensure complete speciation?

Answer 10

No, incomplete speciation may reverse back if the two populations meet again.

Question 11

What other events would lead to speciation?

Answer 11

genetic drift (bottleneck effect and founders effect) and adaptation to different environments

Question 12

Isolating mechanisms exist only to speciate populations. (True/False)

Answer 12

False, this is only true in reinforcement.

Question 13

What are the two steps of speciation?

Answer 13

1. Species must diverge
2. Diverged species must form a reproductive barrier to maintain differences

Question 14

What type of speciation takes place when two populations are geographically isolated?

Answer 14

Allopatric speciation

Question 15

What type of speciation takes place when two populations are not geographically isolated, but still speciated?

Answer 15

Sympatric speciation

Question 16

What are the two types of sympatric speciation?

Answer 16

Polyploidy and disruptive selection

Question 17

Polyploidy is the instantaneous process in which an offspring has more than two sets of chromosomes either through autopolyploidy or allopolyploidy. (True/False)

Answer 17

True

Question 18

What is autopolyploidy?

Answer 18

When an offspring gets more than two sets of chromosomes from one parent.

Question 19

What is allopolyploidy?

Answer 19

When an offspring gets more that two sets of chromosomes from both parents, and extra chromosomes double.

Question 20

What is the term for when an organism has four sets of chromosomes.

Answer 20

Tetraploid

Question 21

What is the term for when an organism has three sets of chromosomes.

Answer 21

Triploid

Question 22

Which is usually fertile, tetraploid or triploid?

Answer 22

Tetraploid, they have an equal amount of sets for meiosis to occur properly.

Question 23

Disruptive selection is the generational process in which a population develops reproductive barriers and different phenotypes without diverging geographically with disruptions. (True/False)

Answer 23

True

Question 24

What are the two types of duration theories in evolution?

Answer 24

gradualism and punctuated equilibrium

Question 25

What is gradualism?

Answer 25

Small changes accumulated over millions of years that lead to a major difference between two species

Question 26

What is punctuated equilibrium?

Answer 26

When a population does not change at all (stasis), but changes immediately within a short period of time (punctuated)

Question 27

Why would a population be in stasis?

Answer 27

1. The environment does not change at all (stabilizes) or the environment switches back and forth with different conditions (oscillates).
2. The population moves toward a similar environment they were once in.

Question 28

Does a population experience either only gradualism or only punctuated equilibrium?

Answer 28

No, a population can experience both in their evolution