1. Muscle Mass: An animal that consistently trains and exercises will develop increased muscle mass. This is not a genetic change, but a physical adaptation to its environment and activity.
2. Calluses: Repeated friction or pressure on an animal's skin can lead to the formation of calluses. These toughened areas of skin are a protective adaptation to prevent further injury.
3. Scars: Injuries that damage skin can leave permanent scars. These are not inherited, but rather physical alterations caused by external factors.
4. Language Skills: Animals, particularly primates, can learn and develop language skills through interaction and training. This is a learned behavior and not a genetic trait.
5. Fear Responses: Animals can develop phobias or specific fears based on negative experiences. These are learned responses, not innate instincts.
It's important to note that acquired traits are not passed down to offspring. Evolutionary changes are driven by inherited traits that are encoded in an animal's genes. Acquired traits are often temporary and specific to the individual.