It is thought that he made wide outcrosses of diverse breeds, and then practiced inbreeding with the intent of fixing desirable characteristics in the crossbred animals.
In some cases, the animals are inbred narrowly for looks, with little regard to health. Although dominance variation is not more complex in theory, it is more difficult to control in practice because of how one allele masks the effect of another.
Researchers partition total genetic variation into additive, dominance, and epistatic types of gene action, which are defined in the following paragraphs. Main article: Backyard breeder In the United States, a backyard breeder is someone who breeds animals, often without registration and with a focus on profit.
Mankind started to create breeds accompanied with artificial selection years ago.
Breeding stock[ edit ] Breeding stock is a group of animals used for the purpose of planned breeding. Chapter 1: Introduction to animal breeding In this first chapter the history of animal breeding is presented.
If a1 dominates a2, the genotypes a1a2 and a1a1 cannot be outwardly distinguished. This leads to producing offspring: the next generation animals.