Pedigree strains bred towards aesthetic goals
in a scientifically informed fashion...
Genetic study: BREEDING STRATEGIES & GENETIC
CONSEQUENCES IN GUPPIES
Guppies are unique in the vertebrate world. They have been bred primarily for color and to a lesser degree shape over the last one hundred years. In many instances with limited consideration for other valuable attributes commonly considered in the livestock world. For this reason many strains lack survivability.
Contributions for many selected phenotypes (color & pattern) are predominantly sex-linked on the Y chromosome and not limited to autosomal genes. Or so it was thought. Many recombine between X & Y chromosomes. Current scientific and breeder theory indicates this may not be totally accurate. We are finding that certain traits thought to be Y-linked are often enhanced or expressed in combination with autosomal components determining expression in independent zones of the body.
As a breeder we can manipulate gene frequencies by non random mating selection in conjunction with: genetic drift, mutation, or the domestic version of population migration in the form of individual acquisitions. It must be remembered that genetic variation can only come about via mutation in existing genes.