If the universe operated under different laws at one time, it would in fact, be an entirely different universe. Such a universe would present an alternate reality. We are products of, and function in, the reality we know as the present universe.
You don't know that, in fact, if man was created, that would not be true. The universe being in an eternal, stable state, then having the spiritual seperated from the physical would not be an alternate reality. It was still man, and we are their children. We simply live in a ver different world. Lifespans, plant growth rates, light, and etc.
But there was still light then, and trees, and sex, and creatures, and a sun, and stars, and cities, and buildings, and etc etc.
It's not only fruitless to speculate on how an alternate reality might operate, but any attempt at connecting such a past with the present cannot be done.
It is easy. The spiritual was simply temporarily seperated.
If Adam and Eve lived in such an alternate reality, we could not call them people. They would be beings, but people are a result of, and exist in the reality we know today.
We are not defined by the prison in which we may live, or the decor of the building, etc. To some extent, we live in a somewhat different world than a few generations ago, when there was no cars, tv, cell phones, computers, nukes, planes, etc etc.
This idea is fodder for fairy tales, science fiction and fantasy writers, nothing else. It's not only incomprehensible, but discussing a universe that doesn't exist, from our reality-trapped minds, is illogical. Our logic applies to this universe.
The past does not exist, or the future, does it??? Yet thet did, and will. It is your present trapped mind that sets the limits, largely.