The Food Chain

1. Photosynthesis and Trophic Levels
2. Why Aliens Probably Wont Eat Us
3. The Design of Life's Food Chain is Evil
4. What Vampires and Zombies Teach Us About Ourselves
5. Conclusions

Photosynthesis and Trophic Levels

There are two polar extremes of life on Earth. Life started deep in the crust of the Earth, where the oxidation of sulphur occured under the metaphorical steam provided by the intense heat from below. These ancient thermophiles eventually multiplied, diversified and evolved to cope with colder and colder climates. When a chance mutation resulted in the production of light-sensitive chemicals, life eventually emerged on the surface and floated in the cooling oceans.₁. Micro-organisms are still the most diverse and successful forms of life on the planet.

“A spoonful of good quality soil may contain ten trillion bacteria representing 10 000 thousand different species! In total, the mass of micro-organisms on Earth could be as great as a hundred trillion tonnes - more than all the visible life put together.”

"The Origin of Life" by Paul Davies (2003)₁

Forgetting the ancient thermophiles, the Sun is the engine that has since kept surface life on Earth sustainable. Photosynthesis converts radiation from the sun into chemically stored energy, creating organic molecules in the process, and expiring oxygen into the atmosphere. The rate of plant growth is called 'production'. Production is measured in grams per meter squared per year. For example, shallow waters produce 2500g/m²/yr. By dividing living creatures into layers, we can examine how energy from the sun makes its way up the food chain in the form of biological chemicals. These 'layers' are called trophic levels:

“The fate of energy can be followed through a consideration of a simple energy transfer model, called a food chain. Each stage in the chain is called a trophic level. Plants are the first level in the chain and are called producers. [...] Herbivorous animals are the second trophic level and are called primary consumers. They in turn are eaten by the third trophic level. [...] At each trophic level a conversion to heat takes place, which means that less energy becomes biomass at the succeeding trophic level. [...] This explains why most food chains are limited to four or five trophic levels, and why the animals at the end of the food chain, for example lions, have to roam over large areas to obtain their food, because one small area cannot support many of them.”

"The Nature of the Environment" by Prof. Andrew Goude, p225-227

Depending on how you count, bacteria makes up nearly 50% of the biomass of the whole Earth₂. That's right - nearly half of all life is bacterial (and over half is microscopic₁). This provides a massive first-layer, primary food source for slightly complex multicellular life forms. Consumption, like all mechanical engines and chemical pathways, is not 100% efficient. Far from it. At all stages, energy is lost to inefficiency, wasteful digestive systems, and heat production. Prof. Dawkins, the foremost evolutionary biologist, informs us that only ten percent of the energy from one trophic level makes it to the next level up₃.

This implies that at most trophic levels, the total biomass must decrease, the feeding/hunting area must be bigger, and the digestive systems have probably evolved to be more complicated in order to digest more complicated fats and sugars. It turns out to be true. Bacteria feed over a very small area, plants and primary producers feed over a wider area but in total, less biomass is held in plants than in bacteria (that make up 50%), and eventually, the predatory animals hunt over wide areas, and are massively fewer in number than their prey.

Why Aliens Probably Wont Eat Us

1. Aliens couldn't digest us (or any other life on the top trophic levels) efficiently enough to have become natural prey to us.
   Energy Efficiency (assuming alien life is a little similar to ours): Life on alien planets could also be dividable into trophic levels; that the greatest abundance of biological chemicals is contained within unicellular lifeforms is great pressure for hungry multicellular species to evolve in a direction that involves digesting single-cell lifeforms. The result is a trophic system. It is also likely that on other planets, as on Earth, the evolution of digestion isn't optimal. The jury-rigged nature of evolution does not mean that the most-efficient routes are always evolved. What works, may survive. In short, there is a maximum limit to the amount of trophic levels you can have. Humans, who shop for food over massive distances (the whole planet), exist at the top level alongside other big omnivores. The footprint of the top hunters is huge, and by and large it is too inefficient for hunters on the top layer to spend time hunting each other. If plankton only process 10% of the sun's energy efficiently, and millions are eaten by fish at only 10% efficiency, etc, it is more efficient for predator fish to eat the next layer down in order to 'collect' the same quantity of plankton-food-mass. To eat each other would result in no net gain of energy into that trophic layer; so, much energy must be obtained from the layers below. At each layer, the storing of fats and sugars gets more complicated. The more complicated the biological chemicals, the harder it is to digest them. That's why bacteria doesn't eat chocolate, but we can. At the top trophic layer, our digestive systems can break-down chocolate into the smaller chemicals prevalent in lower trophic layers, and digest it. We then reassemble it into complex proteins, etc. If aliens visited Earth, they would be unlikely to eat us because the digestive or processing time would be very large (if, of course, they could digest us at all).

2. Alien biological compounds could be comprised of different chemicals to ours, meaning we cannot obtain useful chemicals from eating each other, and probably don't have the right enzymes to digest each other.
   Incompatibility (assuming alien life started-out its evolution with different chemicals in the atmosphere to what we had on Earth): Proteins, carbohydrates and sugars all 'make sense' to animal digestive systems because all life on Earth has evolved from common sources, in an environment rich in their constituent molecules. On an alien planet where advanced life has evolved, if the starting-point was different, the nature of life's building-blocks will be different. Duplicating molecules, the stuff that causes evolution, grows up to use the molecules that are available. The environment shapes the resultant structure of life. We cannot eat silicon-based chemicals, but we can digest carbon-based ones. If a hot planet produces aliens that eat silicon, they might find all life on Earth to be far too insubstantial, and all but inedible. Given the fussiness of what we can eat, and even the dangerous nature of eating food that is too far removed from our historical diets (i.e., fish, plants, small animals, etc), we could probably not eat life that didn't evolve on Earth, nor could they eat us.

But despite these formidable problems, there is another possibility. We know that life can evolve on planets where carbon and other CHOMSP chemicals are abundant and available. It might be that this particular combination is the only efficient way for life to evolve. Of all the planets, life might only evolve on those with the right mix of chemicals. These means that all life could be comprised of many similar chemicals to ours. Not only might there be aliens that can digest us... but all aliens might all be able to digest each other, including us! Although this means that universal cuisine is going to be much more fascinating than planet-by-planet dishes, it also means we haven't quite finished our examination of whether aliens will eat us.

Sometimes, Humans eat each other. We tend to be a food-orientated species. Meals, cooking, meats, sauces, all kinds of plant life and fish, are palatable to us. It might be that we see no reason why we can't eat aliens. Some of us, I dare say, would strive to do so. Some aliens might be similar to some Humans: They would love to find out what an alien tastes like! And, legal or illegal, moral or immoral, they might proceed to do so! What if, then, the first aliens that discover Earth are a species, or even just a group of rogues, who are searching in particular for things to eat? And what if life in the universe is largely carbon-based, and we're edible? Perhaps we would engage in some prisoner exchanges, where instead of cremating criminals who have been executed, we part-exchange them for alien meat!

But, rogues aside, I think it more likely that the more organized alien species are the ones likely to find us, and also these species are less likely to have rogue spaceships wondering around. The foremost evolutionary biologist, Prof. Richard Dawkins, points out (2006) that as species-bias decreases in advanced species, we will seek more and more to avoid harming all other animals. This process is of course evident in Earth history. Alien neurology will lead them to understand that animals and foreign species have feelings like theirs, and will eventually evolve culturally to a point where they seek to avoid pain and harm to others. As a result, the chances are alien governments will not try to eat us. Observe the way that the most advanced countries are the least barbaric, and have the most processed, unnatural foods. If this continues, we will stop eating anything that comes from living material. If aliens continue to evolve technologically, they will likely arrive at the same point. Space travel, especially, requires long-term sustenance on non-living food. Advanced space travellers will probably not eat us, after all, and their governments will probably reign-in any rogue aliens that do try to, just like Human societies monitor their own cannibals and bloodsports practitioners.

So in summary: It is unlikely that aliens would be able to obtain enough energy from us efficiently in order to need to eat us. In addition, if life evolves under various conditions in the universe, aliens will probably have a biochemical make-up so different from ours that we are mutually inedible and potentially very poisonous to each other. But, if life all over the universe is carbon-based and can not evolve elsewise, we might find aliens can digest us (or us them). However, as advanced society relies less on living food and increasingly processes its food, and continue towards non-violence and non-harm towards an increasing range of animals (apes, baboons, Yorkshiremen, etc), and space-travel is (probably) only possible if you can survive on such processed food, it is very likely that space-faring aliens will not be seeking to eat us. Especially as advanced species probably watch out for transgressions amongst themselves, just like advanced moral countries prevent animal cruelty and bloodsports. In short, if we find aliens they probably can't eat us, and wouldn't.

Now, enough about aliens, and back on to purely Earthly and Human concerns, although concerns that are of no less a spurious and otherworldly nature.

The Design of Life's Food Chain is Evil

Many single-cell lifeforms survive off of sunlight, water, and transient chemicals found in the oceans. These simple lifeforms are a Buddhist ideal: They harm no other creatures and feed on nothing living. In a perfect world, all life would have evolved to survive in such a way. With modern technology, we can produce energy to make digestion mostly unnecessary if only we'd have evolved in a way that didn't evolve eating-other-life. All animal life has evolved in a way that makes killing other things necessary. I think that not a single multi-cellular species on Earth survives without directly harming other living life. The Buddhist author Ken Jones describes this as 'ecological violence' and states that it is problematic for Buddhists, who do not want to harm any living thing, that life itself requires violence:

“Ecological 'violence' can equally be seen as ecological 'harmony' and balance. One animal supports the life of another by becoming its prey. 'Violence' harmoniously sustains the life-affirming food chain. Humankind, [...] was part of this harmonious balance of violence-and-peacefulness. [...] Taizan Maezumi, a contemporary Zen Master has observed that if we think of the Buddhist First Precept 'on a common sense level of "Do not kill" or "Do not take any form of life", how could we survive? [...] Survival of life itself depends on killing other forms of life. [...] 'Violence' and 'harmony' [...]. When each disappears, what is there then?"”

"The Social Face of Buddhism" by Ken Jones, p284-285

The author then states that Buddha-nature in us is the cure to this inherent problem, that ethical enlightenment and a Middle Way solves the problem of Human nature. However... all religions think that they have the answer to the problems of Human evil. In the case of Buddhism, it could be said that its solution is exactly the same as common-sense would dictate: Intelligence, moral thinking and societal training are the solutions to redirect out-of-date and antisocial instincts. The best intentions, however, do not change the fact that it is not just Humans that hunt and kill for food and fun, but animals too. Ecological violence is a fundamental part of the cycle of life. All life dies, and all life requires the death of others, in order to live. This 'victory of death' is hailed by Satanists as a supreme sign that if there is a God, it is an evil one:

“If life was created, and not simply the result of undirected unconscious evolution (as seems sensible), this is surely the worst possible way to have created life. It appears very much that life cannot survive without causing suffering for other life. A god could not have created a more vicious cycle if it tried: Tying the very existence of life with the necessary killing of other life is the work of an evil genius, not of an all-powerful and all-loving god, that could choose if it wanted to sustain all life immediately and forever with manna from heaven. But it seems such an all-powerful good god doesn't exist.”

"If There is a God, It is an Evil God" by Vexen Crabtree (2003)

What Vampires and Zombies Teach Us About Ourselves

“Small animals feed on insects. Large animal predators feed on small predators. This is natural. This is normal. We are not surprised when, one level up, we find that we eat "lower" animals, such as rabbits. It's how it is. Our intelligence and development has made us the arbiter of life on this planet. We value Human lives much more than animal life. So, we side strongly with the survivors of zombie plagues and we feel they have every right to survive by killing zombies, because the living are so much better than them. Through several levels of the food chain, we are happy to admit that it is normal for the higher species to use lower species. But why, then, do we draw the line at our level? Vampires, and the elite, are a level better than the untermensch, so why are we appalled when "they" use us according to the natural laws that we accept? We accept natural laws to justify our using of lower species, so how come we find it so repugnant when higher species use us? The reason is that our justification for the food chain is fake; the real reason is necessity. We will do what it takes to keep on top. Likewise, so will vampires. And so will the human survivors of zombie films: They will kill, in order to keep in power.

Zombie and vampire films therefore, teach us much about humanity and the will to power. We learn that the 'natural laws' that we use to justify our existence at the top of the food chain are not the real justifications, and that we are simply self-interested, species-biased and paradigm-biased. Anything better than us we fight against, and anything weaker than us we exploit.”

"Zombies and Vampires" by Vexen Crabtree (2006)

Prof. Richard Dawkins, a foremost biologist and expert in evolution, explains that Human culture has a history of species-ism:

“The feeling that members of one's own species deserve special moral consideration as compared with members of other species is old and deep. Killing people outside war is the most seriously regarded crime ordinarily committed. The only thing more strongly forbidden by our culture is eating people (even if they are already dead). We enjoy eating members of other species, however. [...] We cheerfully countenance the shooting without trial of fairly mild animal pests. Indeed we kill members of other harmless species as a means of recreation and amusement. A human foetus, with no more human feeling than an amoeba, enjoys a reverence and legal protection far in excess of those granted to an adult chimpanzee. [...] The foetus belongs to our own species, and is instantly accorded special privileges and rights because of it.”

"The Selfish Gene" by Prof. Richard Dawkins, p10

Conclusions

What appears at first to be a purely technical matter; studying the rise of energy from basic single-cell life forms through the trophic levels to the predators that gather food over massive areas, can lead us to some serious exobiological, philosophical and even theological debates. Firstly, advanced alien life is likely to find it hard to gain enough energy to survive from digesting us alone, so probably won't be inclined to try. But alien life may well use different metabolic pathways and different biological chemicals so we may find each other utterly inedible and potentially very poisonous. If life in the universe is generally carbon-based, then, it is possible aliens could digest at least parts of us. But they probably won't, as space-faring advanced species have probably out-grown genuine carnivorous diets, as perhaps we are doing by relying on increasingly processed food (eventually grown in vats) coupled with increasing care for animal rights. Now, dietary exobiology aside, the very fact that life evolved from its unconscious, automatic beginnings, to rely on a cycle of life and death (where life survives by killing other life) indicates that if the cycle of life has a 'designer', such a God is an evil one. Only an evil God would design life so that to stay alive, animals have to kill other animals. This 'victory of death' is the exact opposite of what a good god would have designed, where all animals and plants survive on mystical energy from heaven without need for killing or competing for food ('victory of life').