B1.8.1 Evolution

Question 1

What does Darwin’s theory of evolution by natural selection state?

Answer 1

that all species of living things have evolved from simple life forms that first developed more than three billion years ago.

Question 2

Why was the theory of evolution by natural selection only gradually accepted? (3 marks)

Answer 2

• the theory challenged the idea that God made all the animals and plants that live on Earth
• there was insufficient evidence at the time the theory was published to convince many scientists
• the mechanism of inheritance and variation was not known until 50 years after the theory was published

Question 3

Who suggested the idea that changes that occur in an organism during its lifetime can be inherited?

Answer 3

Lamarck

Question 4

How can we classify living organisms into animals, plants and microorganisms?

Answer 4

By studying the similarities and differences between organisms

Question 5

Outline how the process of evolution occurs via natural selection. (3 marks)

Answer 5

• individual organisms within a particular species may show a wide range of variation because of differences in their genes
• individuals with characteristics most suited to the environment are more likely to survive to breed successfully
• the genes that have enabled these individuals to survive are then passed on to the next generation

Question 6

How do new forms of a genes occur?

Answer 6

By mutations