Chapter 11- Evolution Of Populations

Question 1

A measure of how common a certain allele is in a population (different for each allele)

Answer 1

Allele frequency

Question 2

Where does genetic variation come from?

Answer 2

Mutations and recombination

Question 3

The frequency is the highest near the mean value and decreases toward each extreme end of the range.

Answer 3

Normal distribution

Question 4

The observable change in the allele frequencies of a population over time

Answer 4

Microevolution

Question 5

Natural selection can lead to microevolution through what 3 paths?

Answer 5

Directional, stabilizing, or disruptive selection

Question 6

Type of selection that favors phenotype at one extreme of a trait’s range

Answer 6

Directional selection

Question 7

The intermediate phenotype is favored and becomes more common in the population.

Answer 7

Stabilizing selection

Question 8

Occurs when BOTH extreme phenotype a are favor d while individuals with intermediate phenotype are selected against by nature.

Answer 8

Disruptive selection

Question 9

The movement of alleles from 1 population to another

Answer 9

Gene flow

Question 10

Change in allele frequencies due to chance alone, occurring most commonly in small populations

Answer 10

Genetic drift

Question 11

Genetic drift that occurs after an event greatly reduces the size of a population

Answer 11

Bottleneck effect

Question 12

Genetic drift that occurs after a small number of individuals colonize a new area.

Answer 12

Founder effect

Question 13

When certain traits increase mating success.

Answer 13

Sexual selection

Question 14

Competition among males

Answer 14

Intrasexual selection

Question 15

When males display certain traits that attract females.

Answer 15

Intersexual selection

Question 16

Condition in which a population’s allele frequencies for a given trait don’t change from generation to generation.

Answer 16

Hardy-Weinberg Equilibrium

Question 17

What are the 5 conditions need for Hardy-Weinberg Equilibrium?

Answer 17

Very large population, no emigration or immigration, no mutations, random mating, and no natural selection

Question 18

What is the equation for Hardy-Weinberg Equilibrium?

Answer 18

P^2+2pq+q^2 (p= dominant allele frequency/q= recessive allele frequency)

Question 19

What are the 5 conditions needed for evolution?

Answer 19

Genetic drift, gene flow, mutations, sexual selection, no natural selection

Question 20

Occurs when members of different populations can no longer mate successfully with each other.

Answer 20

Reproductive isolation

Question 21

Rise of 2 species from one existing species

Answer 21

Speciation

Question 22

What are the 3 ways populations can become isolated?

Answer 22

Behavioral, geographic, and temporal isolation

Question 23

Isolation caused by differences in courtship or mating behaviors

Answer 23

Behavioral isolation

Question 24

Involves physical barriers that divide a population into 2 or more groups

Answer 24

Geographic isolation

Question 25

Exists when timing prevents reproduction between populations

Answer 25

Temporal isolation

Question 26

The combined alleles of all of the individuals in a population

Answer 26

Gene pool

Question 27

A difference of chemical s cents between 2 populations is an example of what kind of isolation?

Answer 27

Behavioral

Question 28

An earthquake causes an ocean channel to open up on an island where a low are previously existed. The island’s lizard population is now separated on the 2 parts of the island providing an example of what isolation?

Answer 28

Geographic

Question 29

What kind of isolation occurs when 2 populations of birds have different courtship dances?

Answer 29

Behavioral

Question 30

What is considered to be random?

Answer 30

Genetic mutation

Question 31

Like all flowering plants, the snapdragon must be pollinated to reproduce, but its flowers are closed. A bumblebee has just enough weight to open a snapdragon flower by landing on it. This adaptation is an example of what?

Answer 31

Coevolution

Question 32

Evolution toward similar characteristics in unrelated species.

Answer 32

Convergent evolution

Question 33

Analogous structures are an example of what?

Answer 33

Convergent evolution

Question 34

When closely related species evolve in different directions and become increasingly different.

Answer 34

Divergent evolution

Question 35

The process in which two or more species evolve in response to changes in each other.

Answer 35

Convolution

Question 36

Species responds to pressure from the other through better adaptations over many generations. (Convolution can also occur in competitive relationships)

Answer 36

Evolutionary arms races

Question 37

The elimination of a species from Earth

Answer 37

Extinction

Question 38

This occurs when a species as a whole is unable to adapt to a change in its environment.

Answer 38

Extinction

Question 39

Extinctions occur continuously but at a very low rate, usually affect one or a few species in a relatively small area, and can be caused by local changes in the environment.

Answer 39

Background extinction

Question 40

Thought to occur suddenly in geologic time due to a catastrophic event, operates at a global level, destroys many species, and more rare than the other extinction.

Answer 40

Mass extinctions

Question 41

States that episodes of speciation occur suddenly in geologic time and are followed by long periods of little evolutionary change (bursts of evolutionary activity is followed by a long period of stability). Proposed by Miles Eldredge and Stephen Joy Gould.

Answer 41

Punctuated equilibrium

Question 42

The rapid evolution of many diverse species from ancestral specie that are usually adapted to a wide range of environments.

Answer 42

Adaptive radiation

Question 43

What is said to occur when a population is divided and becomes so different from each other that they can no longer mate together.

Answer 43

Speciation

Question 44

What 3 barriers are believed to lead to reproductive isolation?

Answer 44

Geographic, behavioral, temporal

Question 45

What theory states that bursts of evolutionary activity have occurred at geologic time and are then followed by periods of stability with little to no change?

Answer 45

The theory of punctuated equilibrium