Breeding is similar to natural selection in a few ways.
Mutations which enhance these traits are selected for, and they are also passed on. Also, though breeding is done only for human purposes, sometimes traits that people breed for are also selected for in nature. Someone who wants to make goat-hair sweaters would breed goats to have long hair. If a population of goats lives in a cold climate, they could evolve long hair to stay warm. The wheat evolves immunities to diseases and pests naturally to be able to survive and reproduce.