Evolution

Question 1

What is evolution?

Answer 1

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

Question 2

What happens during evolution?

Answer 2

During evolution, changes in allele frequency occur through the non-random processes of natural selection and sexual selection, and the random process of genetic drift.

Question 3

What does natural selection act on?

Answer 3

Natural selection acts on genetic variations in populations.

Question 4

Do populations produce more offspring than the environment can support?

Answer 4

Yes, populations produce more offspring than the environment can support.

Question 5

Who is more likely to be better suited to their environment, individuals with variations or without variations and why?

Answer 5

Individuals with variations that are better suited to their environment tend to survive longer and produce more offspring, breeding to pass on those alleles that conferred an advantage to the next generation.

Question 6

What is sexual selection?

Answer 6

Sexual selection is the non-random process involving the selection of alleles that increase the individual’s chances of mating and producing offspring.

Question 7

What can sexual selection lead to?

Answer 7

Sexual selection may lead to sexual dimorphism.

Question 8

What can selection be caused by?

Answer 8

Sexual selection can be due to male-male rivalry and female choice.

Question 9

How does genetic drift occur?

Answer 9

Genetic drift occurs when chance events cause unpredictable fluctuations in allele frequencies from one generation to the next.

Question 10

In what type of population is genetic drift important?

Answer 10

Genetic drift is more important in small populations, as alleles are more likely to be lost from the gene pool.

Question 11

What is population bottleneck?

Answer 11

Population bottlenecks occur when a population size is reduced for at least one generation, by natural disaster, hunting or habitat destruction. This leaves a small group of organisms possessing a limited range of alleles.

Question 12

What makes the founder effect happen?

Answer 12

The founder effect occurs through the isolation of a few members of a population from a larger population.

Question 13

Why is the founder effect important in genetic drift?

Answer 13

When a small number of individuals break away from a large population for some random reason it leads to a limited number of alleles being represented in the smaller ‘founder’ population. The gene pool of the new population is not representative of that in the original gene pool.

Question 14

How is a gene pool altered by genetic drift?

Answer 14

A gene pool is altered by genetic drift because certain alleles may be under-represented or over-represented and allele frequencies change.

Question 15

What is evolution like when selection pressures are strong?

Answer 15

When selection pressures are strong, the rate of evolution can be rapid.

Question 16

What does the Hardy-Weinberg (HW) principle state?

Answer 16

The Hardy-Weinberg principle states that, in the absence of evolutionary influences, allele and genotype frequencies in a population will determine whether a change in allele frequencies in a population will remain constant over the generations.

Question 17

What can the Hardy Weinberg principle be used for?

Answer 17

The hardy weinberg principle can be used to determine whether a change in allele frequency is occurring in a population over time.

Question 18

What does change suggest?

Answer 18

Change suggests that evolution is occuring.

Question 19

What does fitness indicate?

Answer 19

Fitness is an indication of an individuals ability to be successful at surviving and reproducing.

Question 20

What does fitness refer to?

Answer 20

It refers to the contribution made to the gene pool of the next generation by individual genotypes.

Question 21

What is absolute fitness?

Answer 21

Absolute fitness is the ratio between the frequency of individuals of a particular genotype after selection, to those before selection.

Question 22

What is relative fitness?

Answer 22

Relative fitness is the ratio of the number of offspring per individual of a particular genotype to the number of offspring per individual of the most successful genotype.

Question 23

What is co-evolution?

Answer 23

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

Question 24

What acts as a selection pressure on other species?

Answer 24

A change in traits of one species acts as a selection pressure on the other species.

Question 25

Where is co-evolution frequently seen?

Answer 25

Co-evolution is frequently seen in pairs of species that have symbiotic interactions.

Question 26

How can co-evolutionary relationships be impacted for the individuals involved?

Answer 26

The impacts of these relationships can be positive, negative or neutral for the individuals involved?

Question 27

What are types of symbiotic interactions?

Answer 27

Mutualism, commansalism and parasitism are types of symbiotic interactions

Question 28

What does the red queen hypothesis state?

Answer 28

The red queen hypothesis states that in a co-evolutionary relationship, change in the traits of one species can act as a selection pressure on the other species.

Question 29

What does the Red Queen Hypothesis mean?

Answer 29

This means that species in these relationships must adapt to avoid extinction.