How would you respond to the late Henry Morris’s comments in his book The Genesis Record?:
In the first place, the order of creative events narrated in Genesis 1 is very different from the accepted order of fossils in the rocks representing the geological ages….
Second, as already pointed out when discussing the gap theory, the geological ages are predicated on the fossil record, and fossils speak unequivocally of the reign of suffering and death in the world. The day-age theory, therefore, accepts as real the existence of death before sin, in direct contradiction to the Biblical teaching that death is a divine judgment on man’s dominion because of man’s sin (Romans 5:12). Thus it assumes that suffering and death comprise an integral part of God’s work of creating and preparing the world for man; and this in effect pictures God as a sadistic ogre, not as the Biblical God of grace and love.
Please remember that Morris is a Calvinist. In other words, he accepts predestination and Original Sin. These are not biblical theology. We do not inherit sin genetically from Adam. We are responsible before God for the sins we commit, not sins committed by a person many thousands of years ago.
Many YEC believers unwittingly (or perhaps wittingly) insert their false teaching on Original Sin and total depravity as if they are Christian. That is what is going on here. Calvinists believe that physical death was the result of Adam’s sin. However, this is a very dubious doctrine. I believe that the death inherited by Adam and Eve was spiritual death. Because they sinned, they came under judgment and therefore died spiritually. All of us, also were dead in our sins before we were baptized (Ephesians 2). I do not believe that Adam and Eve were immortal when God created them. They were intended to be eternal, but not immortal. Our physical bodies were not intended to last forever. The curse on Adam and Eve was physical pain and labor, as well as separation from God, as symbolized by being expelled from the garden. The Calvinist assumption that physical death did not exist before the sin of Adam and Eve is not biblical. Besides, it does not even make sense. What were those lions eating? Grass? What about the tiny protozoans and zooplankton? What were whales eating? Plants? Calvinism, and specifically the teaching that animals and plants did not die before Adam and Eve is a false doctrine. It certainly is not evidence against the day/age theory.
My suggestion: Read Romans 5:12 and ask yourself if Paul is speaking about spiritual death or physical death. I believe it is clear. If you are not certain, just read a few more verses along in which he calls baptism a death. Is baptism a physical death? Does your heart stop beating?
I hope this helps.