Evidence for Evolution GCSE

Evidence for Evolution GCSE

LO: To learn how fossils can be used as evidence for evolution.

Success Criteria:

• Describe how fossils provide evidence for evolution and how they are formed.

• Describe why there are very few fossils for early life forms.

• Explain how species can become extinct.

Multiple Choice

Memory Platform: What does extinct mean?

• The species evolved into another species

• There are no organisms of that species alive today.

• There are not enough of the species alive to reproduce.

Multiple Choice

Memory platform: Which one is true?

• Scientists believed that species alive today evolved from species in the past.

• Scientists believed that all the species existed on early earth.

Multiple Choice

Scientists believed that species alive today evolved from species in the past. This is known as:

• Variation

• Natural Selection and Evolution

Multiple Choice

Memory Platform: Which one is true?

• Scientists believed that life evolved from simple life forms.

• Scientists believed that life evolved from complex life forms.

Last lesson we looked at evolution by natural selection.

Today we will study how this theory can be proven through fossils.

Fossils

Fossils provide really good evidence for natural selection.

Fossils are the remains of organisms from millions of years ago found in rocks.

Open Ended

What are fossils?

Fossils form in three ways:

• (1) When parts of organisms have not decayed. This may happen if it is too cold, if there is not enough oxygen or water.

Fossils form in three ways:

(2) If an organism slowly decays but parts of it are replaced by minerals.

Fossils form in three ways:

• (3) Fossils can be the preserved traces of organisms for example their footprints.

Multiple Choice

Sometimes fossils can form when an organism decays slowly however parts of it are replaced with minerals.

• True

• False

Multiple Select

What three conditions are needed for fossils to form?

• Lack of warmth

• Lack of carbon dioxide

• Lack of oxygen

• Lack of water

Multiple Choice

A fossil can be a footprint of an organism.

• True

• False

Open Ended

What are the three ways fossils can form?

There is a problem with fossils!

Many of the earliest forms of life were soft-bodied. This meant that they did not have a skeleton or shell. These organisms rarely formed fossils.

The movement of the rocks in the Earths crust has also led to fossils becoming destroyed.

:(

Due to these reasons there are very less fossils from early Earth. That is why scientists cannot be sure of how life on started.

So how are fossils useful?

They show us that many species have become extinct. This means there are no longer any of those species that exist.

Open Ended

What are some reasons species may become extinct?

Species may become extinct due to:

• Catastrophic events

• Changes in weather patterns

• A new disease/predator

• A new species evolving

Open Ended

What could organisms within a species compete for?

We will now summarize this section through watching a video.

What is the Evidence for Evolution? - YouTube

Open Ended

Share one point that you learnt from the video:

We will now answer some exam questions on what we have learnt today. You will find these in the MS Teams files.