Evolution

Question 1

What is the theory of evolution??

Answer 1

All of todays species have evolved from simple life forms that first started to develop 3 billion years ago

Question 2

Evolution by natural selection
who came up with the theory

Answer 2

Charles Darwin

Question 3

Meaning of Evolution by natural selection

Answer 3

1) Darwin knew that organisms in species show wide variation in their characteristics as well as organisms have to compete for limited resources in a ecosystem.

2) Darwin concludes organisms with the most suitable characteristics for the environment would be more successful competitors and more likely for survive - ‘ survival of the fittest ‘

3) successful organisms that survive can reproduce and pass on the genes for the characteristics that made them successful to their offspring

4) Organisms that are less well adapted less likely to survive and pass on their genes to next generation

5) overtime, beneficial characteristics become more common in the population and the species changes = it evolves

Question 4

Why was Darwin’s theory not perfect ?

Answer 4

1) Relevant scientific knowledge was not available at the time so he couldn’t give a good explanation for why new characteristics appeared and how individual organisms passed on beneficial adaptations to their offspring.

Question 5

What supported Darwin’s idea and how ?

Answer 5

discovery of genetics
Provided an explanation of how organisms born with beneficial characteristics could pass them on -showed that it is genetic variants that give rise to phenotypes and it suited to environment

fossil records
allows you to see changes in organisms over time , example a new discovery, bacteria able to evolve to become resistant to antibiotics

Question 6

Why do species become extinct ?

Answer 6

• Environment changes too quickly
• New predator kills them all
• New disease kills them all
• They can’t compete with another species for food
• a catastrophic event happens that kills them all