Morphic field
The theory of morphic fields conjectures that all living beings have a field associated with them which defines their entire biology. Morphic fields provide a force that guides the development of an organism as it grows, making it take on a form similar to other species. DNA is not the source of structure itself, but rather a "receiver" that translates instructions in the field into physical form.
The fields are but a minor part of a singular universal morphic field encoding the "basic pattern" of all life on every planet.
Morphic fields are reinforced by every successive generation and Gallifreyans were the first sentient life to form in this universe, as a result they created a morphic field for humanoids. (NA: Lucifer Rising)
Behind the Scenes
The theory of morphic fields and resonance originated as a serious Real World scientific proposal. However, most in the scientifc community does not widely accept the idea and most in the scientific community regard it as a fringe science or pseudoscience.
