Final answer:
The exact breed of rabbit described is not specified in the question, but traits suggest a commercial breed similar to Californians or New Zealands. Rabbits with white fur are favored in snowy environments due to natural selection, while gray and Himalayan rabbits blend better in rocky environments. The Himalayan phenotype results from a temperature-sensitive gene affecting fur pigment.
Step-by-step explanation:
The breed of rabbit described in the question, known for its good growth characteristics, white fur, and popularity in shows, is likely referring to the commercial breed often considered second to New Zealands and Californians, which are the most popular for these traits. However, without a specific breed name given, it is difficult to determine the exact breed being referred to. Nonetheless, rabbits with white fur, such as the Californian rabbits, have an advantage in snowy environments due to natural selection, where such fur coloration makes them less visible to predators like foxes and improves their chances for survival and reproduction. This example illustrates how natural selection can lead to certain traits becoming more common in a population over time.
In contrast, in a hypothetical population where the environment is rocky rather than snowy, gray and Himalayan rabbits with gray and white fur may have a better chance of blending in and surviving from predators, leading to diversifying selection. This shows how different traits can be advantageous depending on the specific environment, and thus how natural selection can result in a variety of adaptations within a species.
The Himalayan phenotype is an interesting genetic case where the gene product responsible for fur pigment is temperature-sensitive, leading to coloration only in the cooler extremities of the rabbit's body. This is a fascinating example of how specific alleles can influence the physical characteristics of an organism in a very precise manner.