Evolution

Question 1

Define evolution.

Answer 1

The change over time in proportion of individuals in a population differing in one or more inherited traits.

Question 2

What can alter allele frequency? (3).

Answer 2

1. Natural selection.
2. Sexual selection.
3. Genetic drift.

Question 3

Define natural selection.

Answer 3

A non-random process that acts on variation within a population.

Question 4

What produces variation?

Answer 4

Mutation.

Question 5

What are the three categories of mutation?

Answer 5

1. Deleterious.
2. Neutral.
3. Advantageous

Question 6

Define fitness.

Answer 6

Fitness refers to an overall ability to survive and reproduce.

Question 7

Define sexual selection.

Answer 7

A random process involving the selection of alleles that increase an individuals chances of mating and producing offspring.

Question 8

What is the name given to the phenomenon where male and females of the same species have different phenotypes.

Answer 8

Sexual dimorphism.

Question 9

What are the two categories of sexual selection.

Answer 9

1. Male to male rivalry.
2. Female choice.

Question 10

Describe male to male rivalry.

Answer 10

Large size or weaponry such as antlers or tusks can increase individuals access to females through successful conflict.

Question 11

Describe female choice.

Answer 11

Female choice involves females assessing the fitness of males through observations of honest signals.

Question 12

Explain selection pressures.

Answer 12

How strongly an abiotic or biotic factor influence an environment.

Question 13

Define genetic drift.

Answer 13

A random process which occurs when chance events cause fluctuations in allele frequency from on generation to the next.

Question 14

In which population size is genetic drift more important and why?

Answer 14

Smaller populations.
Because Alleles are more likely to be lost in a smaller gene pool.

Question 15

Describe the bottle neck effect.

Answer 15

When a population size is randomly reduced for at least one generation so lowering the the range of alleles upon which any subsequent selection pressures may act.

Question 16

The founder effect. Define it.

Answer 16

Occurs through the isolation of a few members of a population from a larger population. The gene pool of the new population is not representative of the original population.

Question 17

Describe the Hardy Weinberg Principle.

Answer 17

In the absence of evolutionary influences, allele and genotype frequencies in a population will remain constant over the generations.

Question 18

What are the five conditions of the hardy Weinberg principle.

Answer 18

1. Abcence of natural selection.
2. System of random mating
3. Absence of mutation
4. No gene flow by migration
5. Large population size

Question 19

What is the purpose of the Hardy-Weinberg principle?

Answer 19

To identify whether evolutionary influences are active.

Question 20

What is the equation of the Hardy-Weinberg principle?

Answer 20

p^2 + 2pq + q^2 = 1

Question 21

Describe absolute fitness.

Answer 21

The ratio of frequency of one particular genotype from one generation to the next. (G2:G1).

(Examines one genotype)

Question 22

Describe relative fitness.

Answer 22

Ratio of surviving offspring of one genotype compared to other genotypes.

(Examines different genotypes).

Question 23

Describe co-evolution.

Answer 23

Co-evolution is the process by which two or more species evolve in response to selection pressures imposed by each other.

Question 24

Pairs of species that have a symbiotic frequently demonstrate ________________.

Answer 24

Co-evolution.

Question 25

What are the 3 impacts of co-evolution.

Answer 25

1. Parasitism
2. Commensalism
3. Mutualism

Question 26

What is the importance of genetic drift. (4.)

Answer 26

1. More important in smaller populations as alleles are likely to be lost by chance from a small gene pool
2. Genetic drift can result in a reduction or loss of genetic variation.
3. As alleles are not selected to be beneficial, some alleles retained may be harmful.
4. Certain alleles can be over or under-represented.

Question 27

Describe the Red Queen Hypothesis.

Answer 27

That in a co-evolutionary relationship, change in traits of one species can act as a selection pressure on the other species and that species must adapt in order to survive.

Question 28

What is the distinction between the red queen hypothesis and co-evolution.

Answer 28

The Red Queen Hypothesis reqiures a change in traits.

Question 29

Describe symbiosis.

Answer 29

An intimate relationship with 2 members of different species.

Question 30

Discuss the Red Queen Hypothesis in the context of parasitism.

Answer 30

Hosts that have become tolerant of a parasite have greater fitness. This puts a selection pressure on the parasite to adapt and increase fitness.