Answer: Paul wrote, “By one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned.” (Rom. 5:12).
We are taught, and accept by faith, that when man was created, God breathed into his nostrils the breath of life, a thing never said of animals. Death was to be the result of failure to obey God’s word. Beasts are described as perishing beings — “The beasts that perish.” (Ps. 49:20) Peter says, “Natural brute beasts, made to be taken and destroyed.” (2 Peter 2:12).
Darby makes an interesting observation: God does not answer our curiosity as to the condition of the animals prior to the fall or man. We are told that the creature has got into misery and ruin by our fall, and will not be restored till we are manifested in glory; and this is true even of our bodies. This is morally important for us to know, so that we might be humbled by the way in which man has dragged the animal creation with him. Things will be restored; our glory would be the occasion of the restoration of blessing for all creation. For we know that the whole creation groaneth and travaileth in pain together until now. (Rom. 8:22