A-LevelBiology

A-Level Biology Evolution Revision Notes

Master A-Level Biology Evolution using simple revision notes, key facts and practice questions — all generated by AI for your exam.

Evolution is the process through which species change over time through mechanisms such as natural selection, genetic drift, and mutation. It explains the diversity of life on Earth and how organisms adapt to their environments.

Key Concepts

  • 1Natural selection is the primary mechanism of evolution.
  • 2Genetic variation within a population is essential for evolution.
  • 3Speciation occurs when populations become reproductively isolated.
  • 4Fossil records provide evidence for evolutionary change over time.
  • 5Evolution can occur through gradual changes or rapid bursts (punctuated equilibrium).

Simple Explanation

Evolution is how living things change and adapt over time. It happens because some traits help organisms survive better than others, so those traits get passed on to the next generation. Over many generations, these changes can lead to new species. This process is influenced by factors like mutations and the environment.

Memory Trick

Remember 'Nasty Giraffes Speculate Frequently' to recall Natural selection, Genetic variation, Speciation, and Fossil records.

Flashcards

Question1 / 5

What is natural selection?

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Exam Questions

Describe and explain the process of natural selection. [6 marks]

6 marks
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Define natural selection, describe variation, survival of the fittest, and reproduction.

Explain how genetic drift can affect a population's evolution. [4 marks]

4 marks
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Define genetic drift, provide examples, and discuss its impact on allele frequencies.

What is meant by the term 'adaptive radiation'? [2 marks]

2 marks
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Define adaptive radiation and give an example.

Practice Quiz

Question 1 of 5Score: 0

What is the main mechanism of evolution?

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