Okay, here is what seems obvious to me. First, this whole account of how the earth was made, "This is 'the history of the heavens when they were created, in the day that the Lord God made the earth and the heavens..." Genesis 2:4--We see that this is a history, not anything more. Also, because of other scriptures like how the tree of life and the tree of the knowledge of good and evil are actual trees in which they were not to eat, then I have to take that metaphorical. Plus, the above scripture says that it was a day that the earth was made, where the chapter earlier says it was six days. Surely the whole "Day" thing is figurative, and not litereal. In fact, I would say that it probably was a literary device used by Moses when communicating with the Hebrews. Moreover, this account was assureadly a oral tradition for hundreds of years before recoreded by Moses. Yes I do believe that it was God speaking through Moses when he wrote this down, but you must consider where Moses, as the leader of a escaped slave culture that was deeply in a heathen pagan culture, and there was a need to make sure that they were NOT Egyption. If you check out chapter one, you can see that when we were created in the Image of God, it was for the purpose to filling the earth and subdue it. There is a command given in Chapter one, and that command is to be fruitful and mulitiply, fill the earth and subdue it. No where does it comment that this command was broken. In fact, the first command that was broken was to disobey concerning the tree of the Knowledge of Good and Evil. If that command in Chptr one wasn't broken, then what is to say that there were not thousands of men and women that existed before the fall. What is to say that "Man" or "Adam" isn't figurative. There has to be a point in which to fulfill the reasoning of Christ, there has to be a geneology to prove that Christ was from Mankind and God. He (Christ) is the anti-Adam, for he never partook of the tree of the knowledge of good and evil. Even if Adam were a certain person, there must be an established geneology, and that is what the whole Abel and Seth thing is comming from. There is too much figurative and allagorical language to not say that it isn't to be considered on these terms. Yes I believe that it is certain truth, but it is truth that we must seek by our own relationship with Christ, and then these answers will come to you. I think it is a mix of allagorical and literal accounts of what happened, but I think Moses, filled with the Spirit, used tactical literary devices that brought in the Hebrews to form a national identification, and to show that they are above the animals, which were not to be worshiped, and different from Egypt culture and their influences. So, in consideration of all this, we must look at what was trying to be said by this account, and not intertwine our own cultural values and look for literal language to explain life.
I digress, they were commanded to "be fruitful and mulitply" and there is no evidence to say they did otherwise...