Intrinsically ball retrieving wolf puppies reveal standing ancestral variation for human-directed play behaviour

Domestication dramatically alters phenotypes. Standing variation among ancestral populations often drives phenotypic change during domestication, but some changes are caused by novel mutations. Dogs ( Canis familiaris ) engage in interspecific play with humans and it has specifically been suggested that the ability to interpret social-communicative behaviour expressed by humans is a novel dog-specific skill. Thus, wolves ( Canis lupus ) are not expected to engage in interspecific play with a human based on social-communicative cues. Here we report the observation of three eight week-old wolf puppies spontaneously responding to social-communicative behaviours from a stranger by retrieving a ball. This unexpected and novel observation has significant implications for our understanding and expectations of the genetic foundations of dog behaviour. Importantly, our observations indicate that behavioural responses to human social-communicative cues are not unique to dogs. This suggests that, while probably rare, standing variation in the expression of human-directed behaviour in ancestral populations could have been an important target for early selective pressures exerted during dog domestication.