There are two main atheistic creation models, seeding and simulation.
Seeding (Accidental and Intentional)
This model would be similar to the ‘old earth creationism’ idea by which a superior extra –terrestrial intelligence has set in motion an evolutionary process which would gradually result in intelligent life. The accidental model would involve a chance event such as a comet or meteor striking the Earth which delivers the necessary biological ‘ingredients’ for triggering evolution.
This model would be similar to the ‘young earth creationism’ idea in which the universe we know is brought into existence in an instant. The reality that we perceive is a highly complex computer generated virtual reality.