Theory of Evolution
Practise Theory of Evolution for GCSE Biology with this free worksheet and full mark scheme — Foundation and Higher exam-style questions with worked answers for AQA, Edexcel and OCR. Compare Darwin's theory of natural selection with Lamarck's ideas, and know why Darwin's theory was only slowly accepted.
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These worksheets and mark schemes are original, written for Virtus Academy and checked against the current AQA, Edexcel and OCR specifications. Every worksheet comes with a full mark scheme.
Topic overview
Darwin's theory of evolution by natural selection was published in 1859 in On the Origin of Species, based on observations made during a five-year voyage and on years of subsequent experiment and discussion.
The theory was only gradually accepted, for three reasons. It challenged the idea that God made all the animals and plants on Earth. There was insufficient evidence at the time to convince many scientists. And the mechanism of inheritance and variation was not known until fifty years later.
Alfred Russel Wallace independently proposed the theory of evolution by natural selection and published joint writings with Darwin in 1858, which prompted Darwin to publish his own work the following year. Wallace also did much pioneering work on speciation.
Revision notes
Darwin's theory
Individuals within a species show variation. Those with characteristics most suited to the environment are more likely to survive and breed successfully.
The characteristics that enabled them to survive are then passed to the offspring. He published this in 1859 in On the Origin of Species.
Why acceptance was slow
The theory challenged the idea that God made all the animals and plants on Earth.
There was insufficient evidence at the time to convince many scientists. And the mechanism of inheritance and variation was not known until fifty years after the theory was published.
Wallace and Lamarck
Wallace independently proposed the same theory and published jointly with Darwin in 1858. He also did pioneering work on speciation and on warning colouration in animals.
Lamarck's alternative theory was that changes acquired during an organism's lifetime are inherited. This has been shown to be wrong in the great majority of cases.
Key points
- Darwin published On the Origin of Species in 1859.
- The theory challenged religious beliefs of the time.
- There was insufficient evidence at first.
- The mechanism of inheritance was unknown for fifty years.
- Wallace independently proposed the same theory.
- Lamarck believed acquired characteristics are inherited.
Worked examples
Example 1
Give three reasons why Darwin's theory was only gradually accepted. [3 marks]
Model answer
It challenged the idea that God made all the animals and plants on Earth (1 mark). There was insufficient evidence at the time to convince many scientists (1 mark). The mechanism of inheritance and variation was not known until fifty years after the theory was published (1 mark).
Example 2
Describe the contribution of Alfred Russel Wallace to the theory of evolution. [2 marks]
Model answer
He independently proposed the theory of evolution by natural selection (1 mark), and published joint writings with Darwin in 1858, as well as doing pioneering work on speciation (1 mark).
Example 3
Explain how Lamarck's theory of evolution differed from Darwin's. [2 marks]
Model answer
Lamarck believed that changes an organism acquired during its lifetime would be inherited by its offspring (1 mark), whereas Darwin proposed that inherited variation already present is selected for by the environment (1 mark).
Common mistakes
Saying Darwin's theory was immediately accepted.
It was only gradually accepted, for three specific reasons.
Forgetting Wallace.
He independently proposed the theory and is a required part of the specification.
Saying Lamarck was simply foolish.
His was a reasoned theory that has since been shown wrong in the great majority of cases.
Giving fewer reasons than the marks require.
Three reasons are examinable and each is worth a mark.
Exam tips
- Learn the three reasons for slow acceptance as a set.
- Name Wallace and give his contribution.
- State Lamarck's theory accurately before contrasting it.
- Give the date 1859 for On the Origin of Species.
Key terms
- On the Origin of Species
- Darwin's 1859 book setting out evolution by natural selection.
- Wallace
- The scientist who independently proposed natural selection.
- Lamarck
- The scientist who proposed that acquired characteristics are inherited.
- Speciation
- The formation of new species.
Related topics
Written and reviewed against the current AQA, Edexcel and OCR specifications. Spotted an error? Let us know.