All materialization in the natural world are the manifestation and derivation of the inherent duality of the physical universe.
As citizen of the natural world, our physical form are governed by the dualistic forces of the universe. As we exist in the physical body, our perspective of the world is based on the our observation and experience within the physical world. Duality is the subjective state of mind, while the mind conscious assess the input from the world from an egocentric viewpoint.