There is quite a great deal of debate regarding certain evolutionary concepts; one concept that is especially controversial is the form follows function idea. At the level of anatomy, this idea states that a certain body part will be shaped or built in such a way as to allow it to perform a specific job. The debate regarding this concept can essentially be boiled down what came first, the chicken or the egg? In the sense that scientists are unsure whether a body part first assumes a certain function and then changes over time to assume a proper shape for that function, or if the form of the body part changes first and then assumes a certain function; others claim that the two go hand in hand. Whatever the mechanism, though, it is accepted that there are many examples of body parts being especially well built to perform specific, definite jobs.
The Cardigan Welsh Corgi is a walking example of how form and function blend so well together. While this dog was bred to be a versatile working dog, one of its main jobs was to herd his owner's cattle. His long, low body allowed him to stay clear of the kicks of angry cattle while still allowing him to perform his important herding function by being able to nip at the heels of the cattle. The small stature of the dog, however, was not the only anatomical adaptation to herding that breeders were able to achieve. One look at the Cardigan Welsh Corgi and you'll notice the other prominent feature of this breed: the ears.
The ears of the Cardigan Welsh Corgi are very large, disproportionately so when compared to the rest of the dog's body. Their size is not due to some freak accident in the breeding program (though they might have arisen by accident); these ears have actually been useful to the dog's purpose and so have been maintained through many crosses and breeding programs. These large ears mean that the Cardigan has an extremely acute and sensitive sense of hearing. This sense of hearing made the Cardigan an excellent guardian, as he could hear intruding people and intruding dogs coming from miles away, before his owner could spot them. The dog could also distinguish between familiar sounds and strange, new sounds, so he knew when a member of the family was approaching as opposed to when a stranger was heading his way.
Those ears have also saved the lives of many Cardigans. The ears are able to sense the subtle noises made when a cow begins to pick up his leg to kick. Since Cardigans would herd by nipping at the heels of cows, a kicking cow would have put the Cardigan in the direct line of fire of such a dangerous movement. Their incredibly acute sense of hearing allowed them to anticipate the kick and easily roll out of the way or simply slightly duck their heads.