New
New
Year 9

Evolution

I can explain the theory of evolution by natural selection.

New
New
Year 9

Evolution

I can explain the theory of evolution by natural selection.

Lesson details

Key learning points

  1. Natural selection can cause the common characteristics of a species to change (evolve) over generations.
  2. Scientists explain evolution using the theory of evolution by natural selection.
  3. A scientific theory is a general explanation, developed from evidence, that explains many different examples.
  4. Evolution is not planned in advance; new advantageous features appear randomly and are maintained by natural selection.
  5. Changes in the features of an individual within its lifetime are not evolution.

Common misconception

There are many misconceptions about evolution, including that because evolution by natural selection is a theory it is an untrustworthy explanation.

This lesson builds understanding that a scientific theory is a well evidenced and well tested explanation that is widely accepted by scientists, and also addresses some common misconceptions about evolution.

Keywords

  • Theory - A general explanation that applies to a large number of situations. Theories are widely accepted by scientists because they have been extensively tested and evidenced.

  • Evolution - The process in which the characteristics of species change over many generations, sometimes becoming new species.

  • Natural selection - Organisms that are better adapted to their environment are more likely to survive, reproduce and pass on their genes to their offspring.

Avoid abbreviating “the theory of evolution by natural selection” to “the theory of evolution”, as this can embed the misconception that evolution itself is theoretical, which it is not. The scientific theory is that natural selection is a key mechanism by which the evolution of species takes place.
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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6 Questions

Q1.
There are differences between these four individuals of the same species of giraffe. What is the scientific term for these differences?
An image in a quiz
biodiversity
inheritance
natural selection
Correct answer: variation
Q2.
Giraffes eat leaves from trees, but there is a limited number of leaves. The giraffes are in for the leaves.
An image in a quiz
Correct Answer: competition
Q3.
Which giraffe has an advantage in the competition for food?
An image in a quiz
Correct answer: The giraffe with the longer neck
The giraffe with the shorter neck
Neither giraffe has an advantage
Both giraffes have the advantage
Q4.
Which giraffe is the best adapted to survive?
An image in a quiz
Correct answer: The giraffe with the longer neck
The giraffe with the shorter neck
Neither giraffe is well adapted to survive
The two giraffes are equally well adapted to survive
Q5.
Which giraffe would scientists describe as the fittest?
An image in a quiz
Correct answer: The giraffe with the longer neck
The giraffe with the shorter neck
Neither giraffe
Both giraffes are equally fit
Q6.
Put the statements in order, to explain why giraffes with longer necks became more common in the population.
1 - There was variation between the giraffes.
2 - Long neck giraffes were better adapted to compete for food, so had an advantage.
3 - Giraffes with longer necks were more likely to survive and reproduce.
4 - They were more likely to pass on the genes for a longer neck to their offspring.
5 - Longer necks became more common in each new generation of giraffes.

6 Questions

Q1.
Which of the following provides evidence that the characteristics of species change over many generations?
climate change
extinction
Correct answer: fossils
natural selection
Q2.
The characteristics of species change over many generations, sometimes taking thousands of years. What word do scientists use to describe this process?
Correct Answer: evolution, evolving, evolve
Q3.
Which of these are features of a scientific theory?
Correct answer: It is a general explanation that applies to a large number of situations.
It is based only on common sense.
It is just a best guess that could be true.
Correct answer: It is widely accepted by scientists because it has a lot of supporting evidence.
Q4.
Which of the following statements are true?
An image in a quiz
Chimpanzees and humans are the same species.
Correct answer: Chimpanzees and humans share a common ancestor.
Humans evolved from chimpanzees.
Correct answer: Humans have 99% of their DNA in common with chimpanzees.
Q5.
Match each example to its correct description.
Correct Answer:Learning to play the piano,Not evolution (it’s a learned skill)

Not evolution (it’s a learned skill)

Correct Answer:Getting fitter at the gym,Not evolution (it’s a change within an individual’s life)

Not evolution (it’s a change within an individual’s life)

Correct Answer:Long-legged horses becoming common,Evolution (it’s a change in the features of a species)

Evolution (it’s a change in the features of a species)

Correct Answer:Dodo birds all dying out,Not evolution (it’s extinction)

Not evolution (it’s extinction)

Q6.
Warfarin is a poison used to kill rats. Over many generations, resistance to warfarin has become common amongst rats and it no longer kills them. Who has correct ideas that help to explain this?
Correct answer: Andeep: “When the first rats became resistant it just happened at random.”
Jun: “All of the rats learned to be resistant from the ones that were.”
Correct answer: Laura: “Resistance to the poison became common because of natural selection.”
Sam: “Rats decided to adapt so they could resist the poison.”