Artificial selection
Selective breeding
- In selective breeding (artificial selection), humans — not nature — choose which organisms breed.
- This passes on useful features.
- It is how we shaped our crops and farm animals.
Practice
Selective breeding (artificial selection) differs from natural selection because:
In artificial selection, people choose the breeders to pass on useful features; in natural selection, the environment selects.
Examples
- breeding disease resistance into varieties of wheat and rice.
- using inbreeding and hybridisation (crossing different lines) to make vigorous, uniform maize.
- breeding dairy cattle to improve their milk yield.
Practice
Which is an example of selective breeding?
Breeding cattle for milk yield (or disease-resistant crops) is humans choosing which organisms reproduce.
Practice
Hybridisation in selective breeding means:
Hybridisation crosses different lines (often with inbreeding) to make vigorous, uniform crops like maize.
You've got it
Key idea
- selective breeding (artificial selection) = humans choose which organisms reproduce
- examples: disease-resistant wheat/rice; inbreeding + hybridisation for maize; higher milk yield in cattle
- it passes on the features people find useful