Making Sense of Biology
Nothing in Biology Makes Sense Except in the Light of Evolution, Theodosius Dobzhansky (1973). The American Biology Teacher, 35(3), 125-129.
Nature Red in Tooth and Claw…
This line comes from the poem: In Memoriam A.H.H. by the English poet Alfred, Lord Tennyson. It was completed in 1849 and it is a requiem for the poet’s Cambridge friend Arthur Henry Hallam, who died suddenly of a cerebral hemorrhage in Vienna in 1833. I use this line in all of my introductory lectures about natural selection. It drives home the salient point that all individuals, and by extension species, operate in self-interest. This expression is a six word refutation of natural theology; and at the same time an excellent illustration of the problems entailed in the naturalist fallacy.
Natural Theology held that the beneficence of the creator could be seen in the acts of creation. This thinking goes back at least to Sir Thomas Aquinas (1225/7 – 1274), who wrote in the fifth argument of his Summa Theologie that the existence of God is proved by the order and harmony of the world that there must be an intelligent being in charge. This view was further developed by John Ray’s The Wisdom of God Manifested in the Works of Creation (1691) which relies on argument from design utilizing somewhat sound natural history. Over a century later, Natural Theology would develop its highest form in William Paley’s Natural Theology (1803) and Bridgewater Treatises (1832 – 1840.) These works influenced all of Darwin and all his contemporary scholars. Indeed the structure of on the Origin of Species was designed to counter much of the thinking of natural theology. Natural Theology failed because it cannot explain adaptation. Certainly, somewhat obvious adaptations seem readily explained by “an intelligent being.” Fish, Ichthyosaurs, Dolphins all have torpedo shapes. This shape is hydrodynamic, so there is no challenge to Natural Theology here. However, why create an organism whose chief adaptation, intelligence is made possible by a large head (which makes its infant more difficult to pass through the mother’s birth canal?) Real intelligent design would have altered the infant head growth program to make birth easy, and accelerated its growth after to birth to make learning easier. Numerous other examples abound in nature of suboptimal designs, for example why not design humans with eyes in the back of their heads? Or why design so many microbial life forms that easily infect and often kill these same humans? Attempting to unravel adaptation and organismal diversity using this paradigm quickly became unmanageable.
Closely aligned to Natural Theology is that naturalist fallacy which proceeds from the notion that “all things natural are good.” As a corollary to this thinking, those who operate under the naturalist fallacy assume that humans would be better off if we simply left nature alone. Certainly, if we use the current example of the oil spill going on in the Gulf of Mexico, the naturists might have a point. British Petroleum should have understood that offshore drilling at that depth was fraught with danger. Thus this particular accident and the damage it is producing could have been avoided if we simply did not “mess with mother nature.” However, this line of reasoning is fallacious. It is an example of hasty generalization and selective memory. How about all the other oil platforms around the world that are operating without major accidents? And even if major accidents are inevitable when drilling for oil at these depths, what is are the benefits that result from this enterprise and do they outweigh the costs? Indeed, don’t get me wrong here, what I am not saying is that oil drilling or ongoing fossil fuel use is okay, what I am saying is that the naturalist fallacy is not the way to critique or reject this practice.
Case in point, a colleague of mine who I respect a great deal, suggested that humans should treat other animals utilizing the same ethical and moral principles that we apply to other people. Certainly the organization People for the Ethical Treatment of Animals (PETA) would agree with that notion. Yet I argue that this sort of thinking flows from the naturalist fallacy, as well as anthropomorphism. Charles Darwin remarked in The Origin of Species that if any species could be found, whose behavior solely benefited another species, than his theory of natural selection would be false. Indeed Darwin was absolutely correct. The vast majority of animal species are parasites and many are predatory. Biological communities do show species associations were both species benefit (ants and acacia trees, lichens are algae and fungi, mutualism, +, +); however no species associations have ever been found which show a pattern of a species devoting its energy to the well-being of a second with no benefit coming in return.
Generally, all individuals attempt to maximize their fitness, resulting in their species increasing its abundance and geographical distribution. This often has the impact of decreasing its competitors. This may occur intentionally or unintentionally. Consider the case of our hominid relatives. Modern humans are descended from a lineage that occupied the world with other intelligent hominids. For example, 200,000 years ago the world included the Australopithecines, as well as H. neanderthalensis, H. erectus, and possibly a dwarf human species, Homo floresiensis, found in Java, Indonesia. Archeological evidence exists that suggests that modern humans entered Europe around 55,000 ybp. At that time, their skeletal dimensions suggested that they had tropical physical features, including the possibility that they retained their original dark skin. That evidence also suggests that H. neanderthalensis had temperate/arctic physical features and the MC1R (red hair, light pigmentation gene) has been isolated from Neanderthal DNA. Artifacts associated with both species suggest that H. sapiens was more culturally advanced. New DNA analysis suggests that between 1 – 4% of the DNA of modern Europeans may have originated in Neanderthals1. This means that there had to have been some interaction between these species. We cannot infer that the interaction was aggressive or warlike; however shortly after modern humans arrive in Europe the Neanderthals went extinct. The hypotheses revolve around the competitive exclusion principle of ecology (Gause 1932.) That is, two species which are very close in resource utilization cannot coexist in the same environment. The human/Neanderthal interactions could have included direct warfare, competition for scarce resources, disease, or just chance. Given the ice age conditions of Europe at that time, it is hard to image that there wasn’t some competition; especially since both species would have been hunter gatherers. One model suggests that the modern human capacity for trade to augment scare resources might have given our species an edge in the competition with the Neanderthals2.
One can ask would it have been possible for modern humans and Neanderthals to have treated each other in an ethical manner. Possibly, especially when one considers that they might have been able to communicate via sign language or gestures (we do not know if Neanderthals had speech.) The FOXP2 gene is shared in both humans and Neanderthals; however the anatomy which allowed full speech did not appear until about 50,000 ybp and is never found in Neanderthal fossils3. The idea that humans might as a whole treat other species in an ethical fashion is undermined by our own history of unethical and immoral treatment of each other. Indeed, it is argued that the domestication of animals was a key event in the creation of patriarchal societies in our species. Certainly we do have a consistent history of ethical/moral behavior towards human outsiders; indeed such actions have been the exception and not the rule.
What has been the history of the interaction of humans with non-human species? This is no different from the interactions of any other species in the web of life (e.g. eat or be eaten.) For example, many large bodied predatory mammals were direct dangers to our ancestors (leopards, lions, hyenas, bears, wolves, etc.) For over 95% of our existence, these species dined on many unfortunate humans. In turn, our ancestors dined on smaller or less dangerous mammals (although one has to wonder about the sanity of the Pleistocene humans who hunted the great Mastodons!!) With the domestication of animals and the development of stable agriculture our reliance on hunting declined. Also as our technological abilities grew (smelting of metal, development of projectile weapons) our ability to defend ourselves against large predatory mammals increased. Ancient societies began to breed animals for food. In modern industrial society, humans now breed animals for food on a massive scale. For example, in 2008 the United States beef industry produced 26.56 billion pounds of beef, resulting from the slaughter of 34.4 million head of cattle! Most of this beef is consumed in the United States, that same year only 7.1% of the production was exported. The average American pet receives more animal protein per day than that available to the vast majority of the world’s people! American pets are so well fed, that 25 – 40% of dogs and cats are obese. Thus for most of the world, as the comedian Chris Rock once exclaimed: “Don’t eat no red meat…no, don’t eat no green meat!” Vegetarianism is a luxury that most of the world’s poor and hungry people cannot afford. Case in point, it is hypothesized that the HIV virus may have entered the human population through the practice of butchering “bushmeat” in central Africa. Bushmeat is derived from various monkey species captured, butchered, and sold for consumption. Ironically, bush meat is considered a delicacy by some, and one recent examination of bush meat smuggled in the US has found it contaminated with a HIV-like virus.
Is carnivory a moral choice?
For the vast majority of organisms this is not a question. As Dr. Allan Grant stated in the film Jurassic Park, “the other kind, do what they do.” He was referring to the behavior of Tyrannosaurus rex, which evolved as a stealth/sit and wait predator and wasn’t making moral choices when it attempted to eat Lex and Tim. Throughout the history of life, such predators had no other means of survival. Humans evolved as omnivores. It is hard to reconstruct Paleolithic diets; however we suspect that our ancestors ate whatever they could find including animals, edible plants, especially fruits and nuts. This fact is important in understanding how modern pseudoscientific diet fads are contributing to disease7. Carnivory is not a moral choice for other animals because they do not have the mental capacity to make moral choices. In the words of another movie character, Matt Hooper: “Sharks swim, eat, and make baby sharks. That’s all they do!” Humans on the other hand can decide that they do not wish to eat other animals. Vegetarian diets are possible, although to remain healthy they require planning, since there are some essential amino acids that are hard to get from plants. However, is choosing to be a vegetarian or vegan a moral choice?
Moral reasoning involves making decisions about what we ought to do. What we ought to do depends upon one’s values. Philosophers claim that moral values are those that are worthwhile for their own sake. Our ability to make moral value judgments results from the way our brain evolved and thus were ultimately produced by the selective pressures that made human social life and structure possible. These selection pressures are classically thought of as kin-selection (altruism favoring closely related individuals) and reciprocal altruism (altruism that occurred between unrelated allies that benefited both parties.) While our moral reasoning capacity evolved via genetically based selection, our moral norms evolve via cultural evolution8. For example, some cultures have no problem eating dogs and cats (a practice abhorrent to Americans.) Yet, our consumption of beef cattle is abhorrent to many Hindus. Some Alaska Native tribes still hunt whales for cultural and food purposes. Japan, Norway, and Iceland maintain high volume whaling industries for food consumption. In 2005, Japan was taking 440 minke whales a year from Antarctic waters9. If whale consumption is not abhorrent enough, some cultures have practiced cannibalism. Mostly this practice had shamanist significance, although it is thought that our cousin species the Neanderthals might have eaten their old and sick for survival purposes. With all this said, when does the consumption of other species become a moral choice?
As shocking as this may sound, one species eating another is not a moral issue. One can even argue that people eating other people is not a moral issue (so long as the human bodies involved were not murdered.) In extreme survival situations, this has often occurred. For example, the story which inspired Herman Melvin’s Moby Dick, is based on a real case. In 1820, an American whaling ship (the Essex, captained by George Pollard out of Nantucket, MA) was sank by a sperm whale in the Pacific Ocean. The survivors were stranded on Henderson Island with inadequate food and water. Eventually some took to their boats in an attempt to be rescued. With only four men left in Captain Pollard’s boat (Coffin, Ramsdell, Ray, Pollard) they decided to draw lots to see which of them would be sacrificed to allow the others to live. Charles Ramsdell shot his friend Owen Coffin, and the remaining three lived off his body. After Ray died, Pollard and Ramsdell gnawed the bones of the two skeletons until picked up by Nantucket ship Dauphin 95 days after the sinking of the Essex9.
Might the day after arrive where carnivory might become a moral issue for humans? Possibly, should we ever develop the technology to fully supply the proteins required for human life without the consumption of animal tissue. One can even argue that there are moral (if not scientific) issues concerning how food production is currently achieved. For example, is it morally wrong to feed grain to cattle so that they can be slaughtered to feed the wealthy? I would argue yes, especially if more people can be fed with the grain you gave the cattle. Cows are capable of converting cellulose to protein, so they don’t need to be fed grain. There are range lands that are only suitable for growing cows, sheep, or goats. These animals can produce protein for human populations that are protein limited. It is inefficient to feed grain to livestock. There are other moral concerns in food production; including how mass housing of cattle requires the use of antibiotics to maintain cattle yield. The increased yield comes at the cost of producing more antibiotic resistant bacteria, which endanger human life. The immoral part of this process results from the profit motive associated with this means of producing meat. These are acceptable moral reasons for criticizing the industry, but they do not amount to a moral argument for vegetarianism.
1. Green, R., Krause, J, Briggs, A.W….Paabo, S., A Draft Sequence of the Neandertal genome, Science 328: 710-722, 2010.
2. Horan, R.D, Bulte, E, Shogren, J.F, How trade saved humanity from biological exclusion: an economic theory of Neanderthal
Extinction, Journal of Economic Behavior & Organization, 58(1): 1-19, 2005.
3. Lieberman, P, The Evolution of Human Speech: Its Anatomical and Neural Bases, Current Anthropology 48 (1): 39-66, 2007.
5. Laflamme, D.P, Understanding and Managing Obesity in Dogs and Cats, Veterinary Clinics of North America: Small Animal Practice 36(6): 1283- 1295, 2006.
6. Stonington, J., Bushmeat Presents Latest Food Scare: Researchers Find Strains of a Virus Related to HIV in Illegal Imports of Primate Flesh, a Delicacy to Some Africans, Wall Street Journal, April 14, 2010:
7. Lindeberg, S, Food and Western Disease: Health and Nutrition from an Evolutionary Perspective, (West Sussex, UK: Wiley Blackwell), 2010.
8. Ayala, F.J, The biological roots of morality, Biology and Philosophy, 2(3): 235-252, 1987.
9. Gales, N.J, Kasuya, T, Clapham, P.J, and Brownell, Jr, R.L, Japan’s whaling plan under scrutiny, Nature 435, 883-884, 2005.
10. Philbrick, N, In the Heart of the Sea: The Tragedy of the Whaleship Essex, (New York, NY: Penguin Publishers), 2001.