Natural selection
Individuals with features that suit their environment survive and breed more, passing those features on.
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Analogy
A school sports team where only the fastest keep their place and pass on tips.
In practice
Dark moths survived better on soot-covered trees in cities because birds could not see them as easily.
Practice
Flashcards
- What is survival of the fittest?Individuals best suited to their environment survive and reproduce more.
Interview questions
- Explain how natural selection can lead to evolution.
- There is variation within a species
- Individuals with helpful features survive and breed
- They pass on the alleles for those features
- Over many generations the population changes
Questions people ask
Who came up with the theory of natural selection?
Charles Darwin published it in 1859 in his book On the Origin of Species. Alfred Russel Wallace had reached a similar idea at around the same time. Darwin gathered evidence from his voyage and from studying animals and plants. Today it is supported by fossils and by genetic evidence.
Does natural selection mean animals choose to change?
No. Animals do not choose or try to change. Mutations create new features by chance. If a feature helps survival, individuals with it are more likely to live and breed, so it becomes more common. The population changes over generations. Individuals do not change their genes.