A dog breeder wishes to develop a breed that does not bark. She starts with a diverse mixture
of dogs. Generation after generation, she allows only the quietest dogs to breed . After 30 years
of work she has a new breed of dog "with interesting traits, but on average, the dogs still bark at
about the same rate as other dog breeds. Which of the following "would be a logical explanation
for her failure?
The tendency to bark is not a heritable trait.