What selective breeding is (spec 5.10, 5.11)
Humans — not nature — choose which organisms reproduce, so useful characteristics are passed on.
Selective breeding is when humans choose which plants or animals are allowed to reproduce so that a desired (useful) characteristic is passed on to the next generation. Because it is people, not the environment, doing the choosing, selective breeding is also called artificial selection.
Compare it with natural selection, where the environment decides which organisms survive and reproduce. In selective breeding the human breeder is the one doing the selecting — choosing the cow that gives the most milk, or the wheat plant with the biggest grains.
A desired characteristic is simply a feature that is useful to humans, for example:
- in plants — a higher yield (more food), disease resistance, larger fruit or faster growth;
- in animals — a high milk yield in cows, more meat, more eggs in chickens, or a particular temperament in dogs.
The characteristic must be inherited (controlled by genes), because only inherited features can be passed on to the offspring.
Exam tip. A common one-mark definition is: 'selective breeding is when humans choose organisms with a desired characteristic to breed from.' The words humans/people choose are essential — they separate selective breeding from natural selection.
- Humans choose which organisms reproduce (= artificial selection).
- The aim is to pass on a desired characteristic (useful to humans).
- The characteristic must be inherited (controlled by genes).
See the full worked example for selective breeding in plants and animals →