Evolution by Nutritional Selection

Evolution by Nutritional Selection

Animals need food. They cannot survive and reproduce without it. They therefore have adaptations that ensure that enough food is consumed: traits that enable them to find food and consume it. This is not selfishly confined to the individual animal; animals also procure food for their young, often going without themselves. You have heard about the survival of the fittest; well, this appetite for food is the survival of the fattest—the fullest, the foodiest. The animal that eats well lives the longest and produces the most babies (which it feeds). Evolution by natural selection revolves around food. It is the original biological imperative: eat, eat, eat! Eat or die. And it is constant (unlike sex and reproduction)—the hunger, the searching, the gathering, the consuming. Animals are basically eating machines. They do it in different ways, but they all do it—there are no non-eating species. It is a biological universal (unlike sex and horns). For animals need energy and energy comes in the form of food (originally from the Sun). Animals need fuel (the Sun is their gas tank). The most successful animal, accordingly, is the best eater—the one that always has food available and is able to digest it effectively. This animal will be the most prolific propagator. Evolution is by nutritional selection (not so much sexual selection or aggression selection or intelligence selection).

We can put all this in terms of genes. The selfish gene is the greedy gene—the gluttonous gourmet gene. The greedy gene likes to be well fed; not the individual animal, mark, but the gene itself. Because the selfish gene is equally concerned about identical genes in other bodies, especially offspring. The greedy gene will help build a mother that feeds its descendant genes—it will produce good and plentiful milk for the babies that carry that gene. In mating the greedy gene will favor mates that will best feed its offspring; it will select a mate that brings home the bacon. The male will make the best food gatherer and the female will produce the finest milk. A good parent is one that puts food on the table. Siblings will fight for food, also following genetic imperatives. The genes are food-obsessed because food provides the indispensable fuel for genetic reproduction. A selfish gene with no appetite for food will not survive long in the gene pool.[1] It must build bodies that are ravenous for food and skilled at getting it. Evolution has been perfecting food consumption from its earliest days—from hunting to digesting. Find the food, swallow it down, then effectively digest it (then excrete the remains). The whole ecosystem of an animal (and its genes) is a food ecosystem. Animals copulate, compete, and fight—but mainly they eat. When an animal is described as territorial that is a misnomer; the animal (or its genes) doesn’t care about owning property—it cares about the food that is found on that property. Not territory but the accompanying comestibles; if the animal could get the food without the area it is found in, it wouldn’t bother defending that territory. Who wants to wander round all day defending a piece of land (you can’t eat that)? People used to say that nature is red in tooth and claw; maybe so, but it is also mashed in mouth and belly. Saliva not blood, and violent in the service of eating (as well as mating). Life on earth is all about getting enough to eat.

What about humans? We are a very successful species, probably the most successful in terms of world domination. We are also accomplished eaters: we produce our own food, of all kinds, distribute it, and devote ourselves to consuming it. We have a food economy, restaurants, chefs, TV programs, the works. We are fat to the point of ill-health (is there an obesity problem in any other animal species?). Our huge population growth is made possible by our food productivity. We are not held back by food shortages. We have a food-oriented brain. It is sometimes supposed that we got rid of Neanderthals by making war on them, but perhaps we just out-ate them. We had a better food delivery system. We have taken food to an advanced level, far beyond any other species. We have made food an art and a science. We actually cook (fire was surely crucial in achieving food supremacy). Our culture is centered around food. We now live to eat while other animals eat to live (and do what exactly?). We are the foodie species. We eat everything and we put a lot of thought into it. Our hands are well designed for food gathering and preparation, as well as actual eating. Our tools are often food related. Without our human hands we might not have become so expert in the business of food. Thus, our bipedal gait is a pre-adaptation for food dominance, freeing up the hands for food activity. The hands are perfect instruments for food gathering, food preparation, and food insertion. We even supplement them with utensils (very rare in the non-human world). We go on dinner dates to fancy restaurants with the express purpose of seeing how potential mates conduct themselves around food. Marriage is all about providing and sharing food. Food and sex are closely intertwined. There is also the matter of children: who will be better at feeding them? Back in the day the ideal man would be healthy and strong, good at providing food, while the ideal woman would be good at feeding babies. We might speculate that the attraction of large breasts has something to do with providing plentiful milk for babies; those selfish greedy genes will have their beady eyes on the most nourishing breasts. Big muscles, big breasts—plenty of good grub for all concerned. The naked ape is a hungry ape and wants to be assured of a reliable food supply. Fear of food shortages is a constant anxiety, given the ruthlessness of nature, so you want all the information you can get with regard to a potential mate. Mate selection is nutritional selection, just like natural selection. Animals are selected according to their nutritional fitness. A hopelessly skinny half-starved animal will not do well in the battle for survival and reproduction; it’s survival of the fattest out there. The presence of fat is a guarantee that you won’t starve to death. Given that obesity isn’t generally a problem in the animal world, fat is better than thin, ceteris paribus.

What is an animal? What are the fundamental mechanisms of evolution? These are clearly interconnected questions. One image has it that animals are violent power-hungry brutes out for domination over their fellows; this image reflects social conditions in capitalist Victorian England. Another image views animals as filthy crude pre-human beasts wallowing in squalor; this perhaps reflects the condition of peasants in the Middle Ages, as seen through the eyes of the upper classes. A third image depicts them as libidinous creatures perpetually primed for sex; this picture seems to have taken hold during the 1960s (see Desmond Morris’s The Naked Ape). The present image, derived mainly from TV documentaries, is that of an anxious creature always searching for food—a kind of sentient eating machine. This animal is long-suffering but driven—driven to spend its days in the pursuit of something to eat. I think this view is less anthropocentric than the others: animals really are victims of a mindless evolutionary process that compels them to seek out food or die. They are tragic beings, though in many ways admirable—not violent filthy sex maniacs. Even the apex predators are caught in a cycle of deprivation and lucky relief from starvation (like many unfortunate humans). They eat or die. That is the basic fact of animal life.[2]

[1] The same line of reasoning applies to memes, but I won’t go into this. All replication requires fuel of some sort.

[2] Life on Earth is perhaps unusual compared to other inhabited planets. We are the only civilized eaters on Earth, but on other planets there may be many species with our degree of culinary sophistication (see Star Wars for documentation). There may be even more expert eaters elsewhere with greater planetary domination (galactic domination). The food might be better and more plentiful in these places. The well-fed aliens might have bigger brains, fleeter feet, greater flexibility, and superior morals. We are at the culinary pinnacle here on Earth, but so what?