Final answer:
The Himalayan rabbit is the breed developed in Washington State, characterized by a temperature-sensitive gene product that causes coloration mainly on the cooler parts of its body. In different environments, diversifying selection and natural selection act on rabbit populations to favor the survival of individuals with the most suitable fur color for their surroundings.
Step-by-step explanation:
The breed of rabbit that was developed in Washington State and is known for its unique coloration is the Himalayan rabbit.
This breed's distinct color pattern is due to an allele that produces a temperature-sensitive gene product, resulting in pigment only on the cooler extremities of the rabbit's body.
In a hypothetical population where gray and Himalayan rabbits can blend into their rocky environment better than white rabbits, diversifying selection would likely favor these colorations over white fur.
Rabbits with white fur, however, may have an advantage in snowy or Arctic environments because they are better camouflaged against the snow, thus avoiding predators like foxes.
This is an example of natural selection where the environment influences which traits are beneficial for survival and reproduction. Over time, this can lead to changes in the population's genetic makeup.
In rabbit coat color genetics, different alleles exist that can dictate the amount of pigment produced. The wild-type allele typically produces enough pigment for the standard coloration, but mutant alleles provide varying amounts of this gene product.
The Himalayan phenotype is particularly interesting, as the allele responsible for the color pattern provides a lesser amount of pigment except at the cooler areas of the body. This is similarly seen in the coloration of Siamese cats.