The first natural spirits took life forms as part of the materializing process of evolution. All lives are actually spirits in different forms. Spiritual energy has many different levels. The shape of a human being is an expression of inner adjustment and is the result of self-cultivation through many lifetimes. In certain ancient books their illustrations of our ancestors, the first beings, had nine heads on a snake-like body. Possibly each head did one job at a time, like the intellectual mind does now. The beautiful simplification of the human form and mind evolved through millions of years to have many functions, with one head and two hands and feet instead of many invisible feet beneath the belly. The human form is an artistic work of spirit. If the spirit is correct, it will sooner or later take the right shape. This is similar to a great artist who spends years mastering the skills of his art, yet the value lies in what is actually produced with the skills that were cultivated. Skill is not a totally external development. Inside a great master is the spirit which was there from infancy, waiting to be correctly shaped.
-Hua Ching Ni (Teacher)
Although the physical body of a human has changed considerably from its firm formation or involvement with creation, and will continue to change in the future as Mother Nature makes it (the physical body) more adaptable, the inner essence, consciousness, self awareness (real you) has and always will be the same.
It may be possible that throughout evolution the outer body has changed, but the spirit inside has always been the same.
-Pope John Paul II
If one never learns to transcend one's own body and thoughts, one will never become human (humane).