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What is it and how has it led to a planet which is filled with a huge

variety of living things?

Let’s explore

evolution

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Evolution is a process involving small changes in living things over very long periods of time.

Small changes in living things add up and over time this leads to some new forms of life emerging whilst others die out.

Consider the key terms below, how would you define them?Small changes

occur but the life form stays essentially the

same.

When a life form changes so much that it

becomes a new form of life.

When a life form completely dies

out.

What is adaptation

?

What is evolution?

What is extinction?

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Scientists group life forms by looking at what they have in common. As they learn more about living things these groupings can change.

The main groups for life forms are called Kingdoms. Can you think what the four main forms of life are on our planet?

Did you get

them all?

Let’s explore

evolution

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Scientists group each kingdom of life forms along branches, just like the branches of a tree. Each branch of this ‘Tree of Life’ is called a phylum, the plural for phylum is phyla. Each phylum has evolved from a single kingdom over very long periods of time.

These These categories categories

keep keep splitting into splitting into

smaller smaller groupsgroups

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When life first began on Earth, around 4 billion years ago, there were only a few types of living things; simple single-celled creatures called bacteria. As plants and animals have developed and evolved new forms of life have appeared so that there are now an estimated two million different types of living thing on our planet!Over time the types of living things on Earth have changed dramatically. This is because some survived whilst others became extinct. We know this because we can study living things that have become fossilised, trapped in amber or preserved in other ways.

But how do we know about the changes that have taken place?