Final answer:
Coat color in border collies and Labradors is an example of Mendelian genetics and epistasis. Breeders utilize artificial selection to breed for specific traits while ensuring genetic diversity and healthy pedigree.
Step-by-step explanation:
In the context of border collies, coat color inheritance is an example of Mendelian genetics where certain traits are dominant over others. If black coat is dominant to red coat, it suggests a simple dominance pattern in the genes responsible for coat color. However, the Labrador retriever example demonstrates a more complex form of genetic interaction known as epistasis, where one gene can mask or change the expression of another gene. For instance, a yellow Lab is always ee_, regardless of the B allele because the e allele suppresses the expression of the B allele.
A responsible breeder must consider genetic diversity and avoid inbreeding to reduce the risk of harmful mutations in offspring. Breeders often aim for certain physical traits, such as coat color, while maintaining a healthy pedigree. This process of selectively breeding dogs with preferred traits is known as artificial selection.