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?

A. There is no variation for the trait (barking).

B. The tendency to bark is not a heritable trait.

C. The selection was artificial, not natural, so it did not produce evolutionary change.

D. There was no selection (differential reproductive success) related to barking behavior.

Answer: Option B

Explanation: There are basically two types of traits. Acquired and inherited traits.

Acquired traits: The traits that is acquired from the environment and cannot be inherited from one generation to another generation is known as acquired trait.

Such as time of barking, time of sleeping, amount of food that one animal eats.

Inherited traits: The traits that can be transferred from one generation to another generation is known as Inherited traits.

Example: fur color, height, eye color.

So, the condition here is rate of barking which is not a heritable trait and cannot transferred from one generation to another even by breeding for several generations (option B).