|The divine comedy|
Custance described the process of supernatural selection as form of selection which has the purposefulness of artificial selection but also introduces supernatural forces. He dicussed the hypothesis of supernatural selection in his book Evolution or Creation (1981). According to Custance:
“”The term "Supernatural Selection" be taken to mean that God intervened within Nature, sometimes by acting directly upon the environment to change the conditions of life, sometimes providentially to change the directions of life (as when overruling the chance division of genes in the dividing cell), and sometimes creatively to introduce entirely new forms of life when the total ecology had been suitably prepared to accommodate them. And I believe that this makes better sense of the evidence and is more in harmony with the Christian world view than either blind evolution or fiat creation.
Not theistic evolution
Custance made it clear that supernatural selection should not be confused with the view of theistic evolution, it is not an evolutionary process. According to Custance God acted "creatively, in the most distinct and positive manner conceivable, throughout the whole of geological history, introducing new species as they became appropriate, and removing others when they ceased to be."