From our photographic expectations - again, non-existent at the time - from Abraham on is when things start getting closer to attend what *we* would call "historical". Genesis *is* literal in the sense that what it conveys - that One God created all that exists, that sin and death are not His will for us, that we stray from Him in our disobedience, that neither God nor us are not the first cause of evil some pessimists paint , but an exterior, personal individual being, that God loves and cares about us, and acts in our personal lives and in the historical events that mark humanity, this is all literally true.
Now a personal perspective. This is my own interpretation of Orthodox and other sources, so it is but a theologumen.
I do believe that physical laws have changed in time. In fact, I believe the very nature of time has changed. This is a witness that is universal, even outside Jewish-Christian sources. A "Golden Age" where time somehow developed under different rules, where we were "immortal", and the world a kind of garden for us, and we were created by a God (or gods) is widespread in Human cultures. Maybe it is just a psychological issue, a vice of "old times were better", but I think the resurrection is a precedent to think otherwise.
The resurrection claims nothing less than a change in natural law. We were "prisoners of death" and we no longer are. The rules changed. We will resurrect, and physically speaking, this means entropy will be abolished. Now the abolition of entropy has widely reaching consequences. It can only happen with radical changes to space-time as we know it.
One of the assumptions – and indeed dogmas of faith – of modern science is that the physical laws don’t and can’t change. Jesus’ resurrection is a proof that they can and have changed. If that is the case, the pan-religious concept of “eons” where the very rules of existence are different, becomes more plausible. And all these theories – Genesis included – put our origins in this other space-time where we were “killable” but not naturally “dying”. If that is true, then evolution is just a kind of parallax mistake, it is what the origin looks like from this side of the change of eons, if the laws of nature had always been like they are today.
This is what can be called “Triathlon” model where the runners have to change from swimming, to cycling to running. The rules and means of the race change along the competition. If one tried to explain why and how runner A got there first and assumed that they all had been just running all the time, the person would have to make a lot of assumptions about the speed a human being can run to account for the not-seen cycling period and about how we could have crossed that stretch of water. These assumptions would be correct in that they would account for how a man can cross water or run that much faster. Maybe the scientist from the running perspective would say the man had a different density when crossing the water, and that he was faster because he was younger and lighter, but as he got close to the finishing line he got heavier and more dense. Or maybe he would say that there was an alternative, shorter way for the runners and they had never crossed the water or used the road at all. One of these theories would *necessarily* be true, if running was all that the man could do. But it so happens it is not.
I believe that is what happens to the universe. It could do otherwise in the past and it did. And Jesus came precisely to put reality back on track and bring it closer to Him.