B1.8 Evolution

Question 1

Explain Darwin’s theory of evolution (including natural selection)

Answer 1

• Random mutations cause variations within a species
• A change in the environment such as a new predator will cause animals to compete for survival
• Some animals will have an advantageous allele allowing them to be better adapted and survive
• Surviving animals can reproduce and pass the gene on to the next generation
• Eventually the gene will accumulate in a population

Question 2

Explain Lamarck’s theory of Acquired Characteristics

Answer 2

• He argued that if a characteristic was used a lot by an organism that it would become more developed
• These acquired characteristics would then be passed on to the next generation

Question 3

What was Lamarck’s theory called?

Answer 3

The theory of Acquired Characteristics

Question 4

Why was Lamarck’s theory rejected?

Answer 4

Experiments didn’t support his hypothesis, many characteristics acquired by animals aren’t inherited

Question 5

Give three reasons Darwin’s theory wasn’t accepted.

Answer 5

• It went against religious beliefs at the time
• Darwin didn’t have any good explanation- genes weren’t discovered then
• There wasn’t enough evidence

Question 6

Why do scientists come up with different theories for similar situations?

Answer 6

Scientists produce different hypotheses to explain the same observations because of many reasons e.g they have been influenced by other people or beliefs

Question 7

What are hypotheses refused or supported by?

Answer 7

Data from investigations

Question 8

How are living things classified into animals, plants and microorganisms?

Answer 8

By studying the similarities and differences between them:

• Animals: move around the place and can’t make their own food
• Plants: make their own food and are fixed
• Microorganisms: different cell structure to both plants and animals

Question 9

What is an evolutionary relationship?

Answer 9

How living things are related

Question 10

What is an ecological relationship?

Answer 10

How living things interact with each other

Question 11

What does an evolutionary tree show?

Answer 11

Common ancestors and relationships between organisms.

Question 12

The more recent the common ancestor…

Answer 12

…the more closely related the two species.

Question 13

What do organisms in the same environment with similar characteristics suggest?

Answer 13

That they are in competition with each other

Question 14

What do organisms in the same environment with different characteristics show?

Answer 14

Predator - prey relationships

Question 15

What is the theory of evolution?

Answer 15

The theory that all species have evolved from life forms that first developed more than 3 billion years ago