My first and last statements would be "Ultimately, I don't know."

In between, I'd want to observe that the first bits of Genesis aren't written in the manner of a history book; the form is far closer to poetry. That doesn't mean that we should automatically look for a figurative interpretation, but the choice of a poetic form grants the author a little latitude in presenting the sequence of creation events. The order of that sequence has a definite structure to it:

Day 1: Light
Day 2: Separation of waters (into sky and ocean)
Day 3: Creation of land

Day 4: Light organized into celestial bodies, day/night cycle
Day 5: Creation of aquatic creatures
Day 6: Creation of terrestrial creatures

The themes of the first three days (light, water, land) are repeated in the second three days (light, water, land). What is the message of this organization? My guess is that the primary lesson we're meant to get out of it is an understanding of the nature of God as a creator who loves order. If the historical sequence of creation events is intended as well, it's a secondary message.

We should also consider Genesis 2, which portrays a different order of creation in which man is created *before* the animals. Is this a contradiction of Genesis 1? Only if both accounts are trying to convey literal history. But if the primary intent of one (or both) is to teach us something about the nature of God, then that's what we ought to receive from the text, and leave aside the debate over a literal-versus-figurative six days.

Finally, I reiterate that I don't know the answer to "how did it really happen?" Nor does that ignorance trouble me much. :-)

Iss