Final answer:
New traits like Champagne, Silver, and Charcoal can arise in purebred Labrador Retrievers through mutation, which can affect the expression of fur color genes.
Step-by-step explanation:
In purebred Labrador Retrievers, new traits like Champagne, Silver, and Charcoal can arise through a process called mutation. Mutations are changes in the DNA sequence that can result in new variations of genes, leading to new traits.
Labrador Retrievers have genes that control their fur color. The fur color is determined by two alleles, E and B. Dogs with the ee genotype have yellow fur, while B_E dogs have black fur, and bbE_ dogs have chocolate fur.
If there are variations in these genes, such as mutations that affect the expression of the alleles, it can result in new fur colors like Champagne, Silver, and Charcoal.