People play with animals, and animals participate whole heartedly – think for example of playing fetch with a dog. This turns out to have deep evolutionary roots.
One of my favorite clips to show students is this, where a little girl called Kayla plays with a baby gorilla at the zoo. Separated by a glass wall, the two gambol from side to side, reach toward each other and approach each other face to face. Here, the similarities of the gestures of the human child and the baby gorilla are very striking. The last common ancestor of humans and gorillas lived about 11 million years ago. Thus, we are looking at a long-conserved behavior.
Shown above is a picture of the famous primatologist Jane Goodall with one of the chimpanzees she studied. The last common ancestor of humans and chimps lived around 5 or 6 million years ago. Here is a baby chimp playing with some feline cubs.
Play is clearly an important component in the lives of mammals, and other species, especially birds, are known to play as well. Some reptiles have been known to play with humans. This suggests that playing has evolutionary roots that go back hundreds of millions of years.