Genotype, Environment and Phenotype
Inherited characteristics are controlled by genes and environment and the newcomer to this study of the subject can consider the gene to be a basic unit of inheritance although this is really an oversimplification as will be explained later. Each cat or kitten owns a considerable number of genes and its genetic make-up is called its genotype. The genotype can be likened to a cake recipe which is a collection of ingredients and which is conditioned by mixing and baking to form the cake. The cat is the result of the genotype being conditioned by environment factors to form the adult cat and the outward characteristics of the cat are then described as the phenotype. A cat of a particular phenotype can be produced by a number of slightly differing genotypes while cats of identical genotype may differ slightly in phenotypes. Cakes of slightly different recipes can taste and appear almost identical while cakes if identical recipe may appear and taste quite different. These differences are caused by what are known as environment factors--in the case of the cake the methods of mixing and baking--in the case of the cat the availability and suitability of food, the provision of suitable housing and all other aspects of management.
Therefore it is easy to see that the breeder most likely to succeed is one who has the ability to utilize knowledge gained both in the fields of management and genetics. The development of that ability comes with practical experience and since cat fanciers in general are very helpful in passing on knowledge gained the novice can use their experience as well as his own. The best advice to the fancier new to breeding is to make careful study of both management and inheritance; to carefully select his foundation stock; to employ a method of selection and up-grading of progeny; to keep careful records on order to have reference on where he has gained advantage and where he had gone wrong and to make quite certain that the environment of his cats and kittens is such as to give full opportunity for the production of the healthy and vigorous youngsters desired. Clearly it is useless to design a pedigree for lusty vigorous youngsters and then to keep them in conditions that imperil their health and impede their growth.