Evolution and Natural Selection - Examples of Natural Selection (worksheet)

Question 1

Name 5 examples of natural selection?

Answer 1

Peppered moth.
Bacterial resistance to antibiotics.
Coelocanth.
Lactose tolerance in humans.
HIV resistance in humans.

Question 2

What is the peppered month example?

Answer 2

During industrial revolution, birch wood become black with pollution.
In the changed environment, the black months had a selective advantage and become the most common colour.
White moths became easily predated and become rare.

Question 3

How was the peppered month example discovered?

Answer 3

Kettlewell tested this by releasing dark and light moths in polluted environments and observing selective predation.
Since 20th century pale moths favoured again .

Question 4

What is the bacterial resistance to antibiotic example?

Answer 4

When mutant bacteria appears resistant to antibiotics.
Mutant bacterium has a selective advantage since all normal bacteria are killed leaving mutant cell to reproduce and colonise whole environment.

Question 5

What do some farmers do regarding antibiotics?

Answer 5

Routinely feed antibiotics to their animals preventing infection.
Perfect environment for resistant bacteria to thrive.
Don’t use antibiotic so resistant strain has no selective advantage - die out.