"In the beginning" of what?
Mankind, in our current image and likeness, has been around for 200,000 years. There was a flood as recently as 9000-12,000 years ago. So there is two civilization periods. The book of Genesis starts at somewhere before the first civilization... in the beginning of that time period.
The earth was empty, as in void, as in no land sticking up out of the water. So God had totally flattened the earth, which means the oceans would have covered it to an average depth of 1 1/2 miles. We are not told why he did that, or what pissed him off that time, or if it was just a big mistake. But we are told that God gathered the land together, populated it, then separated the land into continents, and it is terribly obvious that the continents all fit back together. There's a rock cycle, so don't believe any dates in the billions of years for rocks. Maybe believe that dating for stars, but stars aren't rocks, capice?
So God tells man to go "replenish" the earth.
replenish: fill (something) up again. restore (a stock or supply of something) to the former level or condition.
Be fruitful and multiply. So the whole intent in creating man all over again was to reproduce a working civilization. It's a do-over. When a potter goofs up a vase, he smashes the clay down, adds more water, and starts over.
Something like 30,000 to 40,000 years ago, we had some very high tech civilization going on. Which means it was around for another 15,000 years minimum, to reach that point. I'm inclined to believe that the entire 200,000 years played out in the last two civilizations. IOW, there was no cave man bull shit in the past 200,000 years. Man was created intelligent. And there was mankind before this time, but he may not have been made in God's image and likeness. He may have been a cave man... but I doubt it. Even the animals have intelligence, so why would you expect mankind to be less intelligent than the animals? What would be the point in creating animalistic mankind? Again, don't believe any dates in the millions of years for human skeletons. I only believe mankind predates the book of Genesis because the book of Genesis tells me that he did. There is no way a human skeleton survived whatever catastrophe reduced the earth to a perfect sphere covered with water. For that matter, there is no way any skeleton of any creature survived that, except if they were fossilized by it, which they would have, if it was a sudden inundation.
How were the floods created? The land was flattened. Bring down the mountains, bring up the sea floor, and the oceans will cover everything. The first flood was an absolute leveling. The 2nd flood was a partial leveling. The deep trenches in the ocean floor were raised and then dropped, the mountains may have been lowered somewhat and then raised back up, but the water did not cover everything in Noah's flood, it was a docile enough flood for a wooden boat to survive. It would have, no doubt, melted the ice that had formed in North America into the Great Lakes. And it would have created fossils.
So now you see that there was two floods in the Bible. The first one which finished off all mankind and Noah's flood which did not finish off all mankind. The Bible records there were giants before Noah's flood and that they survived the flood, heck, there was still some smallish giants in the land of Canaan in David's time. In Moses' time there was real giants in the land, maybe 12 feet tall, maybe 20 feet tall, before Noah's flood some were 30 feet tall, even 35 feet tall. Figure that was something like 5000-7000 years after the flood, and likely longer. So, there's little doubt that more than Noah's family survived the flood.
Just as there is little doubt that mankind was already on the earth before God created Adam... heck the lands already had names, and already had people in them, so Adam wasn't even the beginning of the civilization before Noah's flood, he was inserted into it. If you think about it, man was created upon the land in chapter one, then God goes back and creates Adam and Eve in a garden he planted eastward in e-den, so civilization was well under way already.
