Darwin's Lost

Fossils Found In

Desk Drawer

Evolution is how species

have evolved

from simple life forms

Theories of Evolution• Lamarck believed

in acquired characteristics.

• The characteristics that help that organism to survive are passed to their offspring.

• So if your parents are body builders then you are born that way.

Theories of Evolution

• Darwin set out in 1831 on a voyage.

• The galapagos islands he saw different features on a variety of finches

The islands

Theories of Evolution

Survival of the fittest

• Only offspring with the genes that best suit their habitat will stay alive and breed.

• This is natural selection.

• Fossils are evidence to show natural selection in action.

•A fast runner on hard ground•It has one toe forming a hoof

•Looks more like the modern horse with one hoof

•Slightly bigger•Walks mainly on one toe

•Has 3 toes on the ground•To run faster on drier ground

•Small•Lives on swampy land•Toes are well spread

Predators

• The dodo was a flightless bird.

• New predators arrived on shore and they could not escape.

Environmental changes

• Scientists believe a big climate change caused dinosaurs to become extinct due to a meteorite crashing into the earth.

Competition

• A mutation can give one animal an advantage over another.

• Or sometimes one species can not compete with another as they are better adapted to their environment, causing extinction.

Diseases

• Diseases can wipe out a whole species quickly when the population live close together.

Extinction

• Predators

• Competition

• Environmental changes

• Diseases

1. What are the two different theories proposed by Lamarck and Darwin, describe them.

2. What is the theory of evolution?

3. Describe how finches helped Darwin to develop his theory.

4. What evidence do we have to prove evolution has taken place?

5. Explain why Darwin’s theory was only accepted gradually (give two reasons).

6. Describe how natural selection works. Give an example of natural selection.

7. What is a mutation? And how can this be advantageous for an organisms?