Evolution

Question 1

What is evolution

Answer 1

The process of things changing over time and many generations to become better adapted to their environment

Question 2

What did Darwin believe and what did Lamark believe?

Answer 2

Darwin - Natural selection

Lamark - Inheritance of aquired chaacteristics

Question 3

Explain how natural selection works

Answer 3

• Individuals within a species show variation because of the differences in their genes (eg some have bigger ears than others)
• Individuals with characerisitcis that make them better adapted to the environment have a better chance of survival and so are more likely to breed successfully (eg big eared animals are more likely to hear their predators and therefore survive to reproduce)
• So, the genes that are respinsible for the useful characteristics are more likely to be passed on to the next generation

Question 4

What is a mutation?

Answer 4

A change in an organisms DNA

Question 5

How can evolution occur due to mutations?

Answer 5

• If the mutation is beneficial by producing a useful characteristic (most have no effect) this may give the organism a better chance of surviving and reproducing
• If so, the beneficial mutation is more likely to be passed on to future generations by natural selection
• Over time, the beneficial mutation will accumulate in a population (eg some species of bacteria have become resistant to antiobiotics)

Question 6

Why did some people not agree with Darwin?

Answer 6

• It went against common religeous beliefs about howlife on Earth developed - it was the first plauside for our existance without the need for a ‘creator’
• Darwin couldn’t give a good explination for why these new, useful characteristics appeared or exactly how individual organisms passed on their beneficial characteristics to their offspring. But then he didn’t know anything about genes or mutations (they weren’t dicovered until 50 years after his theory was published)
• There wasn’t enough evidence to convince many scientist, beause not many other studies had been done into how organisms change over time

Question 7

Explain Lamarks theory

Answer 7

If a characteristic was used a lot by an organism, then it would become more developed during its lifetime

→ eg if a rabbit used its legs to run a lot (to escape predators) then its legs would get longer

Question 8

Why might scientists come up with different hypotheses?

Answer 8

They have different beliefs (eg religious) or they have been inluenced by different people or they just think differently

Question 9

What is the only way to find out if a hypothesis is right?

Answer 9

To find evidence to support or disprove each one

Question 10

Why is Darwins theory now accepted?

Answer 10

Because theres so much evidence for his theory and the discovery of genetics supported it