In the old Christian understanding held by most prior to the age of scientific investigation, (“ancient science” in high cultures just wasn’t the same in purpose and means) Genesis 1 begins with the literal beginning of the known world. Probably it meant that to the ancient Israel too, but with ancient Israel in center and a great deal more appreciation of ANE and covenant symbolism.
With the modern scientific insight, the known world expanded. Before you know there are galaxies, you don’t look for them. Before you know the literal world couldn’t have been literally drowned, simple theology will easily lead you to conclude God did drown the world and so on.
Reading the early Genesis chapters with modern eyes, the symbolism, non-scientific nature and ethnocentrism stands out so clear. We are dealing with the introduction to what would become Israel and world and people outside the mysterious garden is included as implications in the early Genesis chapters. The modern expansion of the known world is irrelevant to the exegesis of the ancient text and its originally intended audience. Nevertheless the ancient records seem prepared for the modern evolution story. In the beginning God created….. God was before creation. Paul speaks of to him exclusively unknown times as before the eons/ages/time/world began in 1 Corinthians 2:7 and other places. We know a bit more but the mind boggling concept of the God that always was outdo any timeline in evolution and is as much a mystery thousands of years ago as today.