This is why evolution as explained today is impossible. It is not possible for death to have entered into the world in any other way than as the scriptures say: "Through one man death came into the world."
If we deny that, then we admit that death is not the result of Adam or mankind's sin (if you go for polygenism). As such, the incarnation loses all of its significance, as does the crucifixion and the entire economy of the incarnation of the Logos. He chose to redeem humanity as the second Adam, but if Adam is not responsible for all, then it is a pointless and empty gesture, and is totally aimed at the wrong source (of death). Theosis becomes impossible, because then the Word incarnate did not become man in order to trample upon death as God-become-man (which loses its entire meaning if death is "natural" and not the result of moral failure), but for no purpose at all. How could he defeat death as the second Adam if it was a part of the order of creation?
No, death must be unnatural, but in order for it to be against nature, it must be foreign to it, and that is not possible unless the order of reality was compromised by free agents. Hence, we come back to Adam and Eve, and the incarnation, and the death and glorious resurrection.