Faces of wolf, dog and human (IMAGE)
Caption
Faces of a wild gray wolf, a Golden Retriever domesticated dog, and a human, along with tissue samples from the orbicularis oris muscle for each species. In the photos the dog and human are actively using the zygomaticus and orbicularis muscles (note the dog’s upturned lip, which mimics smiling). The stained muscle samples reveal similarities in muscle content between dogs and people that likely contribute to their facial flexibility compared to wolves.
Credit
Anne Burrows, Duquesne University, top images copyright iStock.
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License
CC BY-NC-ND