Natural selection can be manipulated by selecting desirable characteristics in crop plants or domesticated animals that are of use to humans.
This is known as selective breeding or artificial selection.
Humans select individual plants or animals with desirable characteristics (such as increased crop yield, disease resistance and longer shelf life). These are then bred to produce offspring.
Repeated selection and breeding over many generations results in all offspring containing the desirable characteristic.
Wheat has been bred over many years to produce the following desirable characteristics: