"Selective Breeding"

When an interesting or useful trait is identified in

 a dog, owners would breed from that dog in the

 hope of the trait being passed on. 

Over many rounds of such breeding attempts,

 especially where two dogs with the same trait

 are bred with each other, traits became fixed. 

There are over 400 breeds of dog in the world 

and all are maintained as pure-bred stocks 

through selective breeding, which aims to

 maintain a closed genetic lineage. 

Most dog traits follow simple genetic rules.

Traits are often referred to as being dominant or

 recessive. Just like humans, dogs have two 

copies of each gene (one inherited from mom

 and one from dad), but the litters making up 

each gene can be slightly different. If a gene 

influences for a particular trait (such as hair 

color, looks) then slight differences in the litters 

in a gene can result in differences in hair color or 

looks in that animal. 


Some of these differences dominate over others,

 so that particular variant of the gene is

 described as being dominant. 

In this case, the hidden trait is called recessive. 

Occasionally, a dog inherits two genes for a

 recessive trait and you get a surprise!


It is common practices to mate the animals who

 only possessed the traits that they found

 desirable for offspring. 


By using the selective breeding mating process.

Selective breeding may involve the traditional 

breeder's approach,which involves breeders 

examining the chosen trait that they want to

 move on to their offspring and selecting breeds

 that exhibit a higher amount or extreme values

 of that trait.


 Eliminate Unwanted Traits

Selective breeding can, and has, effectively breed

 out undesirable traits in some animals.
 
Things like illness and disease have been greatly

 lowered in animals that have been bred to reduce

 them.

Please Note:

NEVER BREED MOTHER TO SON, FATHER TO

 DAUGHTER OR FULL BROTHER TO SISTER

 TOGETHER! 

"THAT IS CALLED INBREEDING."