Selective breeding demonstrates that choosing parents with desired heritable traits can produce rapid, cumulative evolutionary change within domesticated populations over successive generations.
Coverage 2017–2023 · Updated 15 Jul 2026
Artificial selection is evidence for evolution because humans repeatedly breed individuals with desired heritable traits, changing trait and allele frequencies across generations.
Domesticated animal breeds and crop varieties differ greatly from one another and from their original wild species. These changes can occur rapidly when strong selection acts on existing heritable variation.
A response requires variation in the trait, a heritable component, preferential reproduction of selected individuals and repeated selection. Correlated traits may also change because genes and traits are not always independent.
If farmers repeatedly propagate seeds from plants with a heritable high-yield trait, that trait can become more common over generations and the crop variety can diverge from its wild ancestor.
Selective breeding changes a population across generations; feeding one animal well can change its growth but is not inherited evolution. It also does not show that every trait is controlled by one gene.
This objective is assessed through structured response, commonly using Outline.
Outline
Build the answer around this relationship: Selective breeding is artificial selection for desired heritable traits.
Calling selective breeding natural selection when the selecting agent is human choice.
Representative question
Outline the evidence for evolution provided by selective breeding.
The core A4.1 answer moves from evidence to mechanism. Define evolution as heritable population change across generations. Use molecular universals and sequence differences, selective breeding, homology, and convergence as evidence for common ancestry and divergence. Then explain speciation as reduced gene flow followed by divergence of isolated gene pools through selection, mutation, and drift.
