Final answer:
Selective breeding in pets often leads to health issues and deformities. An example is the English bulldog, where selective traits like large heads have led to a high rate of cesarian sections, and a narrowed gene pool increases disease susceptibility. Neotonic traits and sexual selection exemplify evolution's complex influence on domestic animals.
Step-by-step explanation:
Breeding to emphasize certain physical features has become so extreme that it can cause health issues and deformities, disorders, and abnormal behavior.
The correct answer to the question is C) Health issues, deformities. The process of selective breeding in pets often leads to various unintended consequences. For instance, in the case of the English bulldog, due to selective breeding for specific traits, such as large heads and narrow pelvises, most litters must be born via cesarian section.
Furthermore, this selective breeding significantly narrows the gene pool, which increases the susceptibility of the animals to diseases such as cancer, hip dysplasia, deafness, and hereditary conditions.
Selective breeding for neotonic traits, which are juvenile features such as large eyes and smaller snouts, can result in issues like dental problems due to crowded teeth.
The attachment of these traits to a perceived cuteness or domestic ability exacerbates health problems in domestic animals, as these traits do not necessarily correspond with an animal's overall genetic health or ability to survive without human assistance.
Sexual selection is another aspect of evolution that can favor traits that do not benefit an individual's survival but enhance reproductive success. An example of this is the peacock, where the male's large tail may attract predators, but it also attracts mates, highlighting the intricacies of evolutionary pressures and selective breeding.