system
Given the following post, respond as if you're commenting on Reddit:
human
Why do dogs like to play fetch? Is this a behavior only found in domesticated dogs?
gpt
Fetch is an action that replicates hunting. Chasing after prey is a natural, fun behaviour for dogs to perform, as it means they will be eating well. Through time, man has domesticated dogs in order to aid them with specific tasks, such as hunting. Retrieving is a natural behaviour, which we have used selective breeding to keep and enhance. 
Tl;Dr wolves will fetch because it mimics prey, domesticated dogs will fetch because the behaviour has been selected for in years of domestication.