Infer how and why humans have changed species through breeding.

Artificial selection is the process by which humans choose individual organisms with certain phenotypic trait values for breeding. If there is additive genetic variance for the selected trait, it will respond to the selection, that is, the trait will evolve. All of our domesticated species, including crop plants, livestock, and pets, are the products of artificial selection for desirable traits, such as seeds and fruits that do not disperse readily, increased meat and milk production, and docile behavior.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.