Adaptation and Evolution

Question 1

Define the term ‘niche’.

Answer 1

The role of a species within its habitat.

Question 2

What kind of niches can a species occupy?

Answer 2

1. Its interactions with other organisms

2. Its interactions with the non-living envrionment

Question 3

What happens of more than one species tries to occupy one niche?

Answer 3

The two species will compete against each other. One species will be more successful than the other, leaving one species left.

Question 4

What are the 3 types of adaptations are there?

Answer 4

1. Behavioural
2. Physiological
3. Anatomical

Question 5

Define the term ‘behavioural adaptation’.

Answer 5

The way an organisms acts that increases it chance of survival

Question 6

Define the term ‘physiological adaptation’.

Answer 6

The process inside an organism’s body that increases its chances of survival.

Question 7

Define the term ‘anatomical adaptation’.

Answer 7

The structural features of an organism’s body that increase its chances of survival.

Question 8

Describe the process of natural selection.

Answer 8

1. Mutations introduce new alleles into a population so individuals show variation. Some of these alleles determine characteristics that can make the individual more likely to survive
2. Selection pressures create a struggle for survival
3. Individuals without the advantageous alleles don’t survive. This means there is less competition for resources as there are fewer individuals.
4. Individuals with the better adaptations are more likely to survive, reproduce and pass on their advantageous alleles to their offspring.
5. Over time, the number of individuals with advantageous alleles increase.
6. This leads to evolution as the frequency of advantageous alleles in a population increases and the favourable adaptations become more common.

Question 9

What is speciation?

Answer 9

The development of a new species. This is because of changes in alleles and phenotypes in populations.

Question 10

When can speciation occur?

Answer 10

When populations of the same species become reproductively isolated.

Question 11

What changes can trigger speciation?

Answer 11

1. Seasonal changes: individuals from the same species develop different flowering/mating seasons
2. Mechanical changes: changes in genitalia prevent successful mating
3. Behavioural changes: a group of individuals develop courtship rituals that aren’t attractive to the main population

Question 12

What occurs during geographical isolation?

Answer 12

• Individuals of the same species become separated by a physical object. (mountains, river, etc…)
• The conditions on either side of the barrier are slightly different and those best adapted to these new environments will survive.
• The beneficial alleles will be passed on and over time, they will become more common.
• Natural selection will lead to the populations becoming separate species, making the two species unable to produce fertile offspring with each other.