Final answer:
The labradoodle is considered a hybrid dog breed, created by crossbreeding a Labrador Retriever with a Poodle, unlike the poodle, collie, and beagle which are purebred dogs. Hybrids like the labradoodle often combine desirable traits from both parent breeds and can display hybrid vigor.
Step-by-step explanation:
A labradoodle is a hybrid dog breed that has been created through the deliberate crossbreeding of two different purebred dogs, specifically a Labrador Retriever and a Poodle. The labradoodle is known for combining traits from both parent breeds such as the Labrador's friendly nature and the Poodle's hypoallergenic coat.
Unlike a labradoodle, the other dog breeds listed: poodle, collie, and beagle, are not hybrids but are instead considered traditional purebred dogs. Purebred dogs have a documented pedigree in a breed registry. However, a labradoodle is a designer dog and not recognized by all official breed organizations since it is a mix of two different breeds. Hybrid breeds like the labradoodle have become increasingly popular for their unique characteristics and potential health benefits resulting from hybrid vigor.
As a reference to hybrids and selecting traits, a similar process called artificial selection has been used by humans to emphasize desirable traits in dogs. Both traditional breeds and hybrids like the labradoodle have descended from wolves, transformed through artificial selection over generations.
In the context of canine coat genetics, an unrelated example is the fur color in Labrador Retrievers, which is an example of epistasis; this is where one gene interferes with the expression of another gene, such as the E and B alleles influencing the fur color in Labradors.