Now entire complexes of possibilities could be played with, rather than only individual units. The adventurous play of the life forms burst into the bewildering and sublime diversity of the past five hundred million years. All of this profusion of being and beauty is the outcome of play, of risk, of surprise. The creation of new life forms is not determined, but is the outcome of life's intrinsic freedom. Nor is play's manifestation limited to activity at the genetic level.
Life forms play, especially the young of species.
In mammals there is a recognizable difference between the young and the old, not only anatomically, but behaviorally as well, and the most conspicuous behavioral difference is the propensity and ability to play. The young come into the Earth's system of life as if play were what they were created for. They explore, cross the normal limits of things, leap about without reason, climb too far out on limbs, and fall in the water when their curiosity fastens on something new and strange there. Now let's consider the human in all this. Biologists have discovered that in the primate order there is little genetic difference between species.