Selective Breeding in Cats
To the person, selective breeding is collection of poorly understood terms 
and concepts that often seem best left to those who are willing to devote their lives to it. However, selective breeding relies on a few basic concepts as its starting points, concepts that we can all easily grasp.
These concepts were first discovered in the mid-19thcentury by an Austrian monk by the name of Johann Gregor Mendel. Using common garden peas, Mendel was the first person to look at how inherited traits are passed from parent to offspring. He learned that certain patterns of inheritance recur with predictable consistency. He put forth two “laws” that then fell into obscurity until their rediscovery in the early 1900s.Mendel’s first law states that if two parents of pure strains are crossed and they differ in only one trait, for which one has two dominant factors (his word for genes), and the other one has two recessive factors, although offspring of the first generation will display the dominant factor trait. For example, the crossing of true-breeding black-coated parent and a true-breeding blue-coated parent will result in black-coated kittens. Black is dominant over blue.
His second law states that crossing of the offspring will then produce variety in that same trait. Some will look like each of the grandparents in terms of that trait and some will look like neither. Continuing with our example, some of the next generation will have black coats, some blue coats and some will have other-type coats.
Today we understand the inner workings of what Mendel was observing. All features of any cat, any living creature for that matter, are controlled by genes, which are situated on chromosomes. When fertilization takes place, the sperm cell from thermal unites with the egg cell from the female, and tile chromosomas of the created offspring are arranged in pairs. Half of each pair comes from the father, while the other half comes from the mother. Thus, the newly created animal is given its genetic programming; its features have been determined.
Following these laws, which since Mendel’s time have been much further developed, breeders attempt to produce kittens with top show potential by con-tinning the best features of the parents and improving on other features. They can concentrate entirely on the aesthetic qualities, because usefulness of the animal interims of a function need not be considered.
New breeds and varieties are established in one of three ways:
- Mutation was responsible for beginning breeds such as the Sphinx, American Wirehair, Cornish Rex, and Devon Rex. Initial occurrences oaf mutation is impossible to predict, but when they do occur they are passed on to subsequent genera-tins like any other gene.
- Recombination of mutant genes - this generally gives us new color varieties rather than entirely new breeds. It is how breeders eventually developed dozen varieties of the Burmese.
- Ongoing selection of the polygene (also called the quantitative genes) that produce the desired characteristic - no mutation is involved, only the selection for further breeding of the members from each new generation that best demonstrate the desired characteristic. The Siamese has undergone this man-made process for many generations.
Mutation may explain the fact that kittens of domestic cats are not domestic. With most wild. The domestication process must be repeated with each new generation. But domestic kittens are from birth. Mutations that accommodate better adapt-the only ones that generally persist into future.
An important term in breeding is “inbreeding”. Breeding is itself neither good nor bad. It is simply access.
Breeders commonly use inbreeding to purify blood-, breeding the best to the best to get closer to that tar’ cat. Inbred offspring resemble each other more with each new generation. However, caution must be exercised at every step along the way for inbreeding can transfer a harmful recessive mutant trait.