Evolution of species

Question 1

Describe a mutation and the impact of mutations

Answer 1

A mutation is a random change to genetic material and is the source of new alleles in a population.

Mutations can:

be neutral

confer an advantage to survival

confer a disadvantage to the chance of survival

Question 2

Name factors that can increase the chance of a mutation.

Answer 2

Environmental factors such as:

radiation
some chemicals
These can increase the rate of mutation.

Question 3

Describe the impact of a new allele to plants and animals

Answer 3

A new allele can result in the plant or animal being better adapted to their environment.

Question 4

Describe the impact of variation within a population

Answer 4

Variation within a population make it possible for the population to evolve over time, in response to changing environmental conditions.

Question 5

Describe what happens when a species produces more offspring than an environment can sustain

Answer 5

Natural selection or survival of the fittest occurs when there are selection pressures.

Question 6

Describe natural selection and survival of the fittest within a population

Answer 6

The best adapted individuals in a population survive and reproduce, passing on favourable alleles that confer a selection advantage.

Question 7

Describe the process of speciation

Answer 7

Speciation is the formation of a new species that occurs after part of a population becomes isolated by a barrier.

Question 8

Name the 3 types of isolation barrier

Answer 8

The barriers that can isolate populations can be:

geographical
ecological
behavioural

Question 9

Describe the role of natural selection in speciation

Answer 9

After a population becomes isolated, different mutations occur in each sub-population. Natural selection selects for different mutations in each group due to selection pressures.

Each sub-population evolves, until they become so genetically different, that they are two different species.