We think it was between 3-4.5 billion years ago Why can we not be certain how life on earth began?

We think it was between 3-4.5 billion years ago

Why can we not be certain how life on earth began?

How are fossils made?

How do we know the age of a fossil?

Fossils provide evidence of how much or how little different organisms have changed since life began on earth

3 main reasons why species become extinct

a.Destruction of habitat- environment changes too quickly

b.A new predator or diseases kills themc. They can’t compete with another species

for food.

States that all species of living things have evolved from simple life forms which first developed more than 3 billion years ago.

If an organism is born with a useful characteristic which means that the organism is well suited to the environment. It will breed and pass on this useful characteristic.

Mutations can lead to rapid changes in species

What happens if the mutation is a disadvantage?

Why was Darwin's theory of natural selection not agreed with by everyone?

He said that if a characteristic was used a lot then it would become more developed and its offspring would have these characteristics

Eg giraffes long necks