The theory of evolution by natural selection suggests that all modern species evolved from earlier species.
Natural selection causes each generation of a species to become better adapted to its environment.
Natural selection can cause common features of a population to change so much that we classify them as a new species.
Populations of the same species living in different conditions can evolve to become separate species.
An example of speciation of populations living in different conditions (e.g. Galápagos tortoises).

Common misconception

Students often think that animals choose to adapt themselves to their environment.

The language in this lesson has been specifically chosen to avoid embedding this misconception and CfUs help expose this misconception in student thinking.

Keywords

Species - A group of similar organisms that can reproduce and produce fertile offspring.
Speciation - When natural selection causes new species to form.
Natural selection - Organisms that are better adapted to their environment are more likely to survive, reproduce and pass on their genes to their offspring.
Adaptation - A feature that organisms have that helps them live in a particular place and survive.

An issue students have when understanding the theory of evolution by natural selection is comprehending the timescale evolution takes place over. Some examples of evolution can take place in a few generations but the evolution of all life on earth from a single species took billions of years.

Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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Starter quiz

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6 Questions

Q1.

What theory did Charles Darwin propose?

Correct answer: Natural selection

Speciation

Evolution

Q2.

Which of the following is not a stage of natural selection?

Reproduction

Correct answer: Feeding

Variation

Competition

Survival

Q3.

What is the process by which evolution takes place?

Correct Answer: Natural selection

Q4.

What evidence can be used to look at how species have changed overtime?

Experiments

Correct answer: DNA

Correct answer: Fossils

Q5.

Match the word to its meaning.

Correct Answer:Species,Similar organisms that can reproduce and produce fertile offspring.

Similar organisms that can reproduce and produce fertile offspring.

Correct Answer:Adaptation, Features organisms have that helps them survive.

Features organisms have that helps them survive.

Correct Answer:Natural selection,Organisms better adapted to their environment are more likely survive.

Organisms better adapted to their environment are more likely survive.

Q6.

Put these steps in order to show how natural selection takes place.

1 - Variation - individuals of a species have different traits.

2 - Adaptations - features that organisms have that help them survive.

3 - Competition - adaptations allow them to compete successfully.

4 - Survival - allows them to survive.

5 - Reproduction - more likely to have offspring.

6 - Inheritance - likely to pass on the advantageous traits to their offspring.

Exit quiz

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6 Questions

Q1.

True or false? The theory of evolution by natural selection suggests that all modern species evolved from earlier species.

Correct answer: True

False

Q2.

When natural selection causes a new species to form we say has taken place?

Correct Answer: speciation

Q3.

Which of the following is why some Galápagos tortoises have saddle-shaped shells?

Some tortoises stretched up to get food and stretched their shells.

The shape of tortoises’ shells has no relationship to the food they eat.

Correct answer: They were more likely to survive as they could reach more food.

Some tortoises stretched up to get food and passed this onto their offspring.

Q4.

True or false? DNA can be used to help establish relationships between organisms.

Correct answer: True

Fasle

Q5.

Put these in order to show the process of speciation.

1 - Populations of the same species become geographically separated.

2 - The populations, unable to mate with each other, become reproductively isolated.

3 - Different conditions in areas cause different traits to become more common.

4 - Populations are so different from each other they can no longer interbreed.

Q6.

Which of the following is not a geographical barrier that mean species can become isolated?

Correct answer: Trees

Seas

Rivers

Mountains

Deserts