1. God commanded the creatures to be "Fruitful and Multiply." However, as thousands of species, including countless microbes, insects, worms, rodents, etc. obeyed this command and reproduced unchecked (without physical death), the entire earth would soon be awash in a horrific mass of exponentially exploding populations. Indeed, considering the reproduction rates of many invertebrates alone (some producing thousands of offspring in a single generation), within days to weeks at most the Garden of Eden would become a veritable hell on earth. Peace and tranquillity would quickly be replaced with unimaginable overcrowding, pestilence and starvation. A bizarre paradox would also ensue. Soon animals would have no food to eat, nor space in which to live, and yet no ability to die. This is not only an absurdity and logical paradox, it is at direct odds with God's stated plan for a "good" creation.
Obligatory predators: Great White shark,
scorpion, sabre-tooth Cat, rattlesnake,
Widow spider, Lion's Jellyfish,
2. Obligatory carnivores present a serious problem for the "no physical death" positon. Many animals have extensive anatomic features that have little if any use except for capturing, killing, and eating other animals. Whereas some strict creationists assert that some apparent carnivores might have used their sharp claws and dagger-like teeth for grasping or shredding plants, in many cases the features in question seem far better suited, or only suited, for predation. For example, almost all spiders spin webs to capture prey and bear sharp fangs with poison glands to paralyze or kill their victims before devouring them. Likewise, jellyfish, sea anemones, and other Cnidarians have stinging tentacles and stinging cells. Such features are hardly needed for subduing plants. Many other animals have fangs, poison glands, stingers, or other specializations for stunning, capturing and/or eating prey. Numerous bat species have echo-location systems specifically tuned for small insect prey. Owls not only have talons, sharp beaks, and binocular vision well suited for predation, but also special feathers that allow for silent flight while hunting at night. Would they have originally launched stealth attacks on melons and apricots?
Among aquatic animals, obligatory predators include sharks, killer whales, barracudas, and piranhas, just to name a few. Even toothless whales have baleen structures for straining out millions of krill (mostly tiny crustaceans) with every mouthful of water. (Even if one imagined these whales originally fed on some kind of plants, countless small sea animals would inevitably be swallowed with the plants).
Even in the plant kingdom, some species such as sundews and Venus Fly Traps obtain much of their nutrition by trapping and digesting insects and other small animals. Some creationists have countered that perhaps many organisms were changed after the Fall--citing God's curse on the snake to thereafter crawl on its belly. But in many cases the creatures in question would have to be redesigned in such major ways (including the creation of new structures, not just reduction or elimination of old ones) that it would contradict another basic tenet of strict creationism: that God did all his creative work on the first six days, and thereafter rested. Jonathan Sarfati suggests that "since God foreknew the Fall, He programmed latent genetic information that would be switched on at the Fall." However, this raises some sticky theological arguments, and ignores the evidence discussed above that the Bible itself acknowledges the existence of carnivores before the Fall. Also, other problems arise: for example, without physical death the Fall would have been required the Fall to avert a catastrophic population explosion, meaning that humans would loose either way --a concept I doubt most thelogians would endorse.
As an aside, it is obvious that death for plants was part of the creation plan, since Genesis indicates that God gave creatures plant as food (but does not say only plants). While some animals only eat parts of some plants, in many other cases entire plants are routinely uprooted and eaten by a variety of animals. Clearly then, many plants died before the Fall. Some creationists assert that plants are not fully "alive" in the same sense that animals are alive, and therefore cannot "die." However, even if we disregard plants altogether, severe problems remain in a world without physcial death.
3. Many animals have defense mechanisms or structures to fend off predators. These include everything from sharp spikes and spines (as on porcupines and puffer fish) to highly offensive odors (skunks), to poisonous glands in their skin (various amphibians) to corrosive or toxic sprays (skunks, cobras, etc.) to protective armor (turtles, armadillos, etc). Some creatures employ more than one defense mechanism. For example, puffer fish not only have sharp spines, but can inflate their bodies to extend the spines when threatened or attacked.
Sea urchin, porcupine, puffer fish, skunk
Leaf insect and walking stick
Other defense mechanisms include camouflage and mimicry, where creatures like cicadas and "walking sticks" often closely resemble parts of plants or other animals, in order to conceal themselves or repel predators. Poisonous animals are often brightly colored, as well, which evidently serves as a warning to predators. What would be the need for any of these defense systems if all creatures were herbivores? Ironically, strict creationists often cite the Bombardier beetle, which shoots a noxious chemical mixture at predators, as an example of a wonderfully designed creature. But again, what would be the purpose of such a defense system if there were no predators?
4. Animals routinely squash and inadvertently injest other organisms as they walk, eat, and carry out their daily activities. With every meal, even obligatory herbivores typically swallow a multitude of tiny animals such as aphids, mites, insect larva, etc, besides millions of microbes. Are we to assume that not a single elephant, cow, or rhino (let alone dinosaur) would ever accidentally ingest or step on a single ant, spider, or worm, or that God was continually rescuing millions of tiny animals from such fates? On a smaller scale, billions of bacteria and other microbes are continually reproducing and dying as part of the normal microecology of larger animals, within their digestive and disease fighting systems. Why would disease fighting systems even exist if no creatures could ever die?
5. Many animals (and humans) die every day from a variety of accidents (falling, choking, suffocating, etc). For this to never occur, we would have to assume that none of the originally created creatures were capable of errors in judgment, balance, movement, etc., or that God continually saved them from any accidental deaths. But there is no Biblical or scientific justification for these secondary assumptions. Indeed, Genesis says that the original Creation was "good," not perfect. Only the latter would prevent accidental deaths.
6. Physical immortality would require a total cessation of all aging processes. The problem is, as long as their were sunlight, background radiation, bacteria, etc. in the original creation, its hard to imagine how absolutely zero aging would occur, unless there was a continuous and perfect rejuvenation process. But again, God did not say the original creation was perfect, just good. Moreover, as already discussed without aging and death, the original creation could not stay "good" for very long, and would soon become unimaginably hellish with exponentially exploding population growth.
7. As noted by Glenn Morton, if creatures were meant to be immortal, there would be no need for reproduction. God could simply have created the optimal number of creatures of each kind, and they would have lived forever. Reproduction is thus tied to the cycle of life and death. Reproduction is needed to replace dying individuals. Death is also needed to avoid unchecked reproduction and its devastating results, as already discussed, and is ecologically important (point 8 below).
8. Death is ecologically important. It allows for the dissipation and recycling of nutrients in the environment. For example, when plants and animals die, their bodies are decomposed by other organisms (mostly microbes and fungi) which return nutrients to the earth, allowing plants to grow. Stop all death, and such cycles eventually stop, preventing plants from growing. Without plants, many animals which eat only plants cannot live. And yet if there is no death, then they cannot die, and we are left with another absurdity and paradox.http://paleo.cc/ce/nodeath.htm