One thing I forgot to mention in the last chapter is a moderately popular theory amongst some theological circles, which is that the flood (what we will see shortly) was the first time in world history that water fell from the sky. The basis of this claim is Genesis 2:6, where it says that "a mist used to rise from the earth and water the whole earth's surface". By implication, some scholars claim that this means there was no rain from the sky until the flood occurs when the "floodgates of the sky were opened" (Gen 7:11).
The only problem I have with this theory is that it relies entirely on inference. The bible does not say that water *only* rose from the ground, and it doesn't say that the flood is the first time water fell from the sky either. Given that early Genesis has a strong tendency towards omitting what the author perceives as irrelevant content, I think it's absolutely possible and perhaps even likely that it could have been raining for thousands of years and given that it isn't important to the storyline, be left out.
Nevertheless, the claim that the flood is the first time the world experienced rain makes for good moralizing, as people imagine Noah's disbelief at being told water would fall from the sky, that he had to build the boat by faith, not knowing what would come, and that everyone around him thought him insane for building a boat to protect against something unknown. (This last one is actually pretty realistic. Even if they were used to rain from the sky, building this massive boat to protect against a worldwide flood seems very extravagant and would definitely appear foolish.) So I have some skepticism towards this theory also, even though the lessons drawn from it are usually pretty reasonable.
Now, for chapter 7. God first tells Noah that he will bring a pair of every animal onto the ark, to save it from the floodwaters. This brings me to another point I forgot to mention about the last chapter, which is the effect of human wickedness on nature. While it may seem almost tautological these days to assert that bad human behavior is destroying the planet, this is not always evident in the past, before the mechanized destruction of species that began sometime around the 18th to 19th centuries. What this passage tells us clearly demonstrates otherwise, as human wickedness results in the destruction of nearly all animal life on the planet. In my opinion this is clearly related to the mandate found in chapter 1, to rule over the earth and subdue it.
This leads into the broader issue of human dominion which I cannot address due to space constraints, but to summarize for this passage, humans were given authority over the earth to do good. However, they chose to do evil and since they hold authority, their evil resulted in broad destruction over the earth. While some skeptics may say that the flood came from God and not man, it is clear from chapter 6 that the flood is the result of human wickedness on the earth, so in truth it really is caused by man. We still have this power today, and that's why there is so much destruction on the earth today. In the extreme, some environmentalists just want all humans gone from the earth, but in truth we really just need to return to balance and peace with God, and then peace with the earth will follow.
In a similar vein, the obedience of Noah results in saving a pair of every animal as well, so even though the sins of a generation destroys nearly all the animals, the righteousness of one man preserves a remnant of them.
Some non-literalists question the possibility of having a pair of every animal, as they claim X number of species of elephants and so forth. This is again interpolating a modern viewpoint about the technical term "species" being equivalent to "animal" here, when the original Hebrew is not nearly as strict, as an "animal" could reasonably correspond to any level of the biological tree, whether that be genus or phylum or whatever biologists use today to differentiate creatures. Given the pendulous fluctuations in so-called modern biology, you'd think naturalists today would be more lenient to the ancients who were not gifted with our modern debates and acrimony. Anyway, that's not something I care about, so I will move on.
From verse 7, we discover that the righteousness of Noah results in saving not only himself, but his entire family of dependents. This gets back to the issue of authority/dominion. Since he was (in accordance with the culture of the time) the authority figure over his wife, children and their dependents, then his righteousness or wickedness would spill over into their lives. In this case, him walking with God results in them being saved from the flood as well.
Another thing to note is that before the flood, the animals were at peace with man. It is stated in chapter 1 that man only ate fruit and vegetables from the trees. It is only later (in particular, after the flood which we will see later) that man begins eating meat. Before the flood, there is no warfare between man and animal because they lived in harmony in accordance with the will of God. This is not directly stated, but it is easy to infer from all of the animals peacefully walking into the ark and neither being afraid of Noah nor attacking one another. So it is possible that none of the animals would attack each other before the flood. This implies that there were no carnivores before the flood, or more accurately, that the "carnivores" as we understand them today simply didn't eat meat then and somehow got by on a different diet. Or as Isaiah 11:7 puts it, "and the lion [ate] straw like the ox". While Isaiah 11:6-9 is a forward-looking prophecy, it can be reasonably applied as a backwards-looking statement regarding pre-flood Eden.
The rest of the chapter is a description of the flood and the ark and it possesses quite a bit of specific measurements about the flood's duration and scope. Unlike the description of the ark, these are observations and not directions, so they aren't exactly the same "kind of numbers". Nevertheless, one can reasonably wonder how the author would have this level of detail. There are really just three answers: he made it up (what most naturalists say), God told him (what most evangelicals say), or it was passed down from generation to generation (I have no idea who says this). The last one is probably the least likely, though given the oral culture of the time, it perhaps not completely out of the question. Ironically, if one looks at the larger story (the flood as a whole), then it becomes increasingly likely to be an oral tradition, so perhaps I shouldn't write off option #3. It's just that maintaining an accurate level of detail over hundreds or even thousands of years is very difficult. Even written tales get corrupted gradually, and oral traditions tend to be much more malleable.
Of course, this comment does not just relate to Gen 7. It can be equally applied to all of the events in early Genesis (before chapter 11 or so), which everyone agrees (including conservative scholars) was written long after the events it describes. So to anyone who ascribes to biblical literalism, you have to deal with the difficult provenance issue: how can a story be passed down for so long with no mistakes? The answer invariably falls to something like #2, God told the author what to write, and what he was told was perfectly accurate.
My perspective is that this whole debate over literal accuracy is, at least with respect to the numbers, arguing a whole lot over a whole little. I don't really care if the water was 15 cubits over the mountains or 30 cubits or whatever. The broad strokes are important, but the specific details that get fought over so much really don't impact the interpretation of the chapter.
Anyway, that's all I can think of. We will continue with the flood story in chapter 8.