Evidence for evolution — AQA GCSE Biology
Test yourself on Evidence for evolution with AQA GCSE practice questions.
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Evidence for evolution explained
Darwin proposed that characteristics are passed from parents to offspring, but he did not know how inheritance worked.
Read the full explanation
Modern genetics provides the mechanism: genes are sections of DNA that code for characteristics, and they are passed from parents to offspring in gametes. Alleles are different versions of a gene, and the combination of alleles an offspring inherits affects its characteristics. This explains why variation exists in a population and why advantageous characteristics can become more common over generations. Understanding genes therefore supports Darwin’s theory by showing how inherited variation arises and how natural selection can change populations over time.
Your focus
- Describe how genes and alleles are passed from parents to offspring.
- Explain how knowledge of inheritance supports Darwin’s theory of evolution.
- Use the idea of alleles to explain variation within a population.
Evidence for evolution exam tips
Marking Points
- Genes are sections of DNA that carry the instructions for characteristics and are passed from parents to offspring.
- Alleles are different versions of a gene, and different combinations of alleles produce variation within a population.
- Inherited variation is the raw material on which natural selection acts, because some alleles give a survival advantage.
- Knowledge of genes supports Darwin’s theory by explaining how characteristics are inherited and how populations can change over generations.
Examiner Tips
- 💡Use the terms gene, allele, DNA and gamete accurately when explaining inheritance.
- 💡Link inheritance explicitly to natural selection by stating that advantageous alleles are passed on and become more common.
- 💡Avoid saying that an organism ‘has a gene for’ a trait in a way that ignores alleles; refer to alleles where variation is involved.
Common Mistakes
- Confusing genes with alleles; the correct idea is that a gene is a section of DNA and alleles are different versions of that gene.
- Thinking that acquired characteristics can be inherited; the correct idea is that only genetic information passed in gametes is inherited.
- Believing that Darwin knew about genes; the correct idea is that the genetic mechanism was discovered later and now provides evidence for his theory.