Biology Under the Influence

Dialectical Essays on the Coevolution of Nature and Society

Richard Lewontin, Richard Levins

• Publisher: Monthly Review Press
• Year: 2007
• ISBN:
  9781583673928
• Topic: Scienze biologiche
• Subtopic: Biologia

How do we understand the world? While some look to the heavens for intelligent design, others argue that it is determined by information encoded in DNA. Science serves as an important activity for uncovering the processes and operations of nature, but it is also immersed in a social context where ideology influences the questions we ask and how we approach the material world. Biology Under the Influence: Dialectical Essays on the Coevolution of Nature and Society breaks from the confirms of determinism, offering a dialectical analysis for comprehending a dynamic social and natural world.

In Biology Under the Influence, Richard Lewontin and Richard Levins provide a devastating critique of genetic determinism and reductionism within science while exploring a broad range of issues including the nature of science, biology, evolution, the environment, pubic health, and dialectics, They dismantle the ideology that attempts to naturalize social inequalities, unveil the alienation of science and nature, and illustrate how a dialectical position serves as a basis for grappling with historical developments and a world characterized by change. Biology Under the Influence brings together the illuminating essays of two prominent scientists who work to demystify and empower the public's understanding of science and nature.

PART ONE

1
The End of Natural History?

Biologists in the present century find themselves in a deeply contradictory position on questions of diversity and change. They are the inheritors of a nineteenth-century natural historical and evolutionary tradition in which the immense diversity of organisms and the long-term change that has occurred in the living world were at the very center of interest. There are millions of distinct species now extant representing less than 0.1 percent of all the species that have ever lived, and these too will become extinct. Yet only a minute fraction of all the kinds of organisms that might be imagined have ever or will ever exist. No two individuals within a species are identical, the species composition is always changing, population sizes vary markedly from year to year, and the physical conditions of life are in constant flux.

In the late eighteenth and nineteenth centuries, the ideology of change, central to the bourgeois revolutions and the social upheavals necessary for the growth of capitalism, was transferred easily onto the natural world. Herbert Spencer declared change to be “a beneficent necessity,” and although it made Tennyson sad, he heard nature cry, “I care for nothing, all shall go.” But the bourgeois revolutions succeeded and the Whig interpretation of history has become Whig biology. We are at the End of Natural History. The world has settled down, after a rocky start, to a steady state. Constancy, harmony, simple laws of life that predict universal features of living organisms, and the self-reproduction and absolute dominance of a single species of molecule, DNA, are the hegemonic themes of modern biology. Biologists suffer from a bad case of physics envy, and no branches of biology have been more ruthless in their search for a Hamiltonian, a single equation whose maximization will characterize the entire biosphere, than ecology and evolution. Indeed, the price of admission into “real science” for these natural historical fields has been to give up their concentration on change and contingency and to prove their status as science, rather than mere butterfly collecting, by producing some universal predictive laws. If there must be change, at least let it be caused by some simple law-like force.

On the model of Newtonian physics, change and diversity, rather than being the natural state of things, become deviations from the natural state of rest or regular linear motion, deviations that must be explained by externalities. But there’s the rub. In classical physics, systems are sufficiently isolated from each other so that their ideal motion can be studied in isolation, taking into account the effect of an external impetus. The moon will continue in its utterly predictable course around Earth unless some very large object intrudes from outer space. But every population, species, and community, indeed the whole damned biosphere, is constantly changing in what appear to be unpredictable ways. Nor are the boundaries between the system and outer space so clear. How are we to explain system change as a result of unpredicted externalities if we are not sure what is external?

There have been two responses, one from a prescientific tradition, and one from the bowels of physics itself.

The first kind of response denies the constant turnover and instability of living organisms while it alienates the human species from the rest of nature and reasserts the reality of the distinction between artificial and natural. Human technological society, disturbing the natural world from its normal state of harmony and balance, becomes the externality. In a transformation of quantity into quality, what was in the early stages of its evolution just another part of the harmonious balanced whole, escapes into another sphere of action and becomes an autonomous actor dominating and exploiting the rest of nature from the outside. It does this, of course, at its peril, since, like any exploiter, it may extinguish both itself and the system that supports it by imprudent exploitation. Under this model, the task of science is to uncover the laws of behavior of the unperturbed natural world and to use these laws to hold in check the effects of the external perturbing force.

The other response does not attempt to identify externalities that cause unpredictable irregularities in an otherwise simple law-like system, but denies the very existence of the irregularities and asserts the predictability of the biosphere from simple generating principles. There have been three such attempts in the last twenty-five years, whose names are metaphors for the anxiety of meaninglessness that has engendered them. They are catastrophe theory, chaos theory, and complexity theory. All are attempts to show that extremely simple relationships in dynamical systems will lead to what seem at first sight to be unpredictable changes and extraordinary diversity of outcome, but which are, in fact, utterly regular and law-like.

Catastrophe theory—developed in the 1960s by the mathematician Rene Thom—shows that in some systems, which are changing in time according to quite simple mathematical laws, the changes observed may be continuous and gradual deformations of the state at a previous instant, and at a critical point the entire shape of the system will undergo a “catastrophic” change and then continue its development along a totally new pathway. Many physical deformations under continuously increasing force will reach a critical point at which they will break like a bent branch. The classic example, known by sometimes painful experience to the denizens of the Malibu beach, is the breaking wave. As a swell develops into a deep convex curve there is a continuous deformation of shape whose tubularity is suddenly and catastrophically lost at a critical point in its roll, and the wave comes crashing down. The practitioners of catastrophe theory hoped that it would provide the explanation of changes in shape during the development of individual organisms, and of the extinction of species, among other things, but there is currently no trace of this theory in biological practice. Indeed, the externalities view has more recently triumphed in the claim that truly “catastrophic” events, meteor impacts, rather than mathematical catastrophes, have been responsible for a major part of species extinctions. The fascination with the possibility of these external catastrophes has resulted in a complete neglect of the question of why every species goes extinct, with or without meteors.

In the 1980s, chaos theory was introduced to show that some very simple dynamic systems may go to equilibrium or undergo regular oscillations in one range of parameters and in other ranges will pass from one state to another in what appears to be a totally random fashion, but which in fact can be exactly predicted, moment by moment, from the equations of motion. So an uncertain and diverse world is really the solution to a trivially simple equation. In particular, mathematically chaotic regimes were offered as an explanation for the unpredictably varying population sizes that species typically display from generation to generation. Where chaos theory reigns, historical contingency disappears. The entire demographic history of a population from its initial condition is already immanent in the deterministic equation of its growth and is completely fixed by processes internal to the organisms that make up the population. No reference need be made to historical processes in the outside world or to random variation that arises from the finiteness of real populations. Thus far, biologists have been unable to make use of chaos theory outside of the speculative realm, because no one knows how to reconstruct these hypothetical ahistorical equations of motion from data that appear as random.

Most recently the thinkers at Santa Fe Institute have begun to develop a theory of complexity which, they promise us, will generate the dazzling variety of life histories from the behavior of networks of simple entities with lots of simple connections. Not wanting to break with previous speculations, they also claim that living systems are “at the edge of Chaos.” There will be “laws” of complexity of which life will be one example, but only one. Complexity theory is yet another attempt to produce a theory of order in the universe, though one that is vastly more ambitious than astrophysics. Not only was the entire history of the stars immanent in that millionth of a second when the universe began but the history of life as well. It is not simply that we have reached the end of history, there never was any history to begin with.

None of these theories, all meant to tame diversity and change, and most important, to expunge historical contingency, envisions the alternative, that living beings are at the nexus of a very large number of weakly determining forces so that change and variation and contingency are the basic properties of biological reality. As Diderot said, “Everything passes, everything changes, only the totality remains.”

2
The Return of Old Diseases and the Appearance of New Ones

A generation ago, the commonsense position of public health leaders was that infectious disease had been defeated in principle and was on the way out as an important cause of sickness and mortality. Medical students were told to avoid specializing in infectious disease because it was a dying field. Indeed, the Epidemiology Department at the Harvard School of Public Health specialized in cancer and heart disease.

They were wrong. In 1961, the seventh pandemic of cholera hit Indonesia; in 1970, it reached Africa, and South America in the 1990s. After retreating for a few years, malaria came back with a vengeance. Tuberculosis has increased to become the leading cause of death in many parts of the world. In 1976, Legionnaires’ disease appeared at a convention of the American Legion in Philadelphia. Lyme disease spread in the Northeast. Cryptosporidiosis affected 400,000 people in Milwaukee. Toxic shock syndrome, chronic fatigue syndrome, Lassa fever, Ebola, Venezuela hemorrhagic fever, Bolivian hemorrhagic fever, Crimean-Congo hemorrhagic fever, Argentine hemorrhagic fever, hanta virus, and, of course, AIDS, have confronted us with new diseases. The doctrine of the epidemiological transition was dreadfully wrong. Infectious disease is a major problem of health everywhere.

Why was public health caught so completely by surprise?

Part of the answer is that science is often wrong because we study the unknown by making believe it is like the known. Often it is, making science possible, but sometimes it is not, making science even more necessary and surprise inevitable. Physicists in the late 1930s were lamenting the end of atomic physics. All the fundamental particles were already known—the electron, the neutron, and the proton had been measured. What more was there? Then came the neutrinos, positrons, mesons, antimatter, quarks, and strings. And each time, the end was declared.

But the explanation demands something more than the obvious fact that science will often be wrong. Before we can answer why public health was caught by surprise, we have to ask: What made the idea of the epidemiological transition seem so plausible to the theorists and practitioners of health?

There were three main arguments:

1. Infectious disease had been declining as a cause of death in Europe and North America for nearly a hundred and fifty years, since the causes of mortality were first systematically recorded. Smallpox was almost gone, tuberculosis was decreasing, malaria had been driven out of Europe and the United States, polio had become a rarity, and the childhood scourges of diphtheria and whooping cough were on their way out. Women were no longer dying of tetanus after giving birth. Just look ahead: the other diseases would go the same way.

2. We had ever better “weapons” in the “war” against disease: better laboratory tests to detect them, drugs, antibiotics, and vaccines. Technology was advancing, while the germs had to rely on their only ways of responding—by mutations. Of course, we were winning.

3. The whole world was developing. Soon all countries would be affluent enough to use the advanced technologies and acquire a modern health portrait.

Each of these arguments was loosely plausible, and each of them wrong. The problem is that although they seem to be historical arguments, they completely lack an understanding of historical contingency or the way in which historical changes alter the conditions of future change.

First, public health professionals had too short a time horizon. If instead of counting only the last century or two they had looked at a longer period of human history they would have seen a different picture. The first confirmed eruption of plague—the Black Death—hit Europe in the time of the Emperor Justinian when the Roman Empire was in decline. The second plague spread in fourteenth-century Europe during the crisis of feudalism. What the relation of economic and political events was to these outbreaks is unclear, but when the historical record is more complete the causal paths are easier to follow. The great plague of northern Italy at the beginning of the seventeenth century was directly consequent to the famine and widespread movement of armies during the dynastic wars of the period. And the most devastating epidemiological event we know of accompanied the European conquest of the Americas, when a combination of disease, overwork, hunger, and massacre reduced the Native American population by as much as 90 percent. The Industrial Revolution brought the dreadful diseases of the new cities that Engels wrote about in relation to Manchester in his The Condition of the Working Class in England.

So instead of the claim that infectious disease is in decline forever, we have to assert that every major change in society, population, use of the land, climate change, nutrition, or migration is also a public health event with its own pattern of diseases.

Waves of European conquest spread plague, smallpox, and tuberculosis. Deforestation exposes us to mosquito-borne, tick-borne, or rodent-carried diseases. Giant hydroelectric projects and their accompanying irrigation canals spread the snails that carry liver flukes and allow mosquitoes to breed. Monocultures of grains are mouse food, and if the owls and jaguars and snakes that eat mice are exterminated, the mouse populations erupt with their own reservoirs of diseases. New environments, such as the warm, chlorinated circulating water in hotels, allow the Legionnaire’s bacteria to prosper. It is a widespread germ, usually rare because it is a poor competitor, but it tolerates heat better than most, and it can invade the larger but still microscopic protozoa to avoid chlorine. Finally, modern fine-spray showers provide the bacterium with droplets that can reach the furthest corners of our lungs.

Second, public health was narrow in another way: it looked only at people. But if veterinarians and plant pathologists had been consulted, new diseases would have been frequently seen in other organisms: African swine fever, mad cow disease in England, the distemper-type viruses in North Sea and Baltic mammals, tristeza disease of citrus, bean golden mosaic disease, leaf-yellowing syndrome of sugarcane, tomato Gemini virus, and the variety of diseases killing off urban trees would have made it obvious that something was amiss.

The third way public health was too narrow was in its theory: not paying any real attention to evolution or the ecology of species interactions. Theorists of public health did not realize that parasitism is a universal aspect of evolving life. Parasites usually don’t do too well in free soil or water and so they adapt to the special habitats of the inside of another organism. They escape competition (almost) but have to cope with the partly contradictory demands of that new environment: where to get a good meal, how to avoid the body’s defenses, and how to find an exit and get to somebody else. The subsequent evolution of parasites responds to the internal environment, external conditions of transmission, and whatever we do to cure or prevent the disease. Large populations of crops, animals, or people are new opportunities for bacteria and viruses and fungi, and they keep trying.

A deep problem is the failure to appreciate the evolutionary change that occurs in disease organisms as a direct consequence of the attempts to deal with them. Public health theorists did not consider how the bugs would react to medical practice, even though drug resistance had been reported since the late 1940s and pest managers already knew of many cases of pesticide resistance. The faith in magic bullet approaches to disease control and the widespread use of military metaphors (“weapons in the war on …”; “attack”; “defense”; “come in for the kill”) made it harder to acknowledge that nature, too, is active, and that our treatments necessarily evoke some responses.

Finally, the expectation that “development” would lead to worldwide prosperity and major increases in resources applied to health improvement is a myth of classical development theory. During the Cold War, challenges to the World Bank/IMF approach to development were marginalized as communist. In the actual world of dominance of already formed rich economies, the poor nations obviously could not close the gap with the rich, and even when their total economies grew it did not mean that the mass of people prospered or more resources were devoted to social need.

More deeply, social processes of poverty and oppression and the actual conditions of world trade were not the stuff of “real” science that deals with microbes and molecules. So a cholera outbreak is seen only as the coming of cholera bacteria to lots of people. But cholera lives among the plankton along the coasts when it isn’t in people. The plankton blooms when the seas get warm and when runoff from sewage and from agricultural fertilizers feed the algae. The products of world trade are carried in freighters that use seawater as ballast that is discharged before coming to port, along with the beasts that live in that ballast water. The small crustaceans eat the algae, the fish eat the crustaceans, and the cholera bacterium meets the eaters of fish. Finally, if the public health system of a nation has already been gutted by structural adjustment of the economy, then the full explanation of the epidemic is, jointly, Vibrio cholerae and the World Bank.

So, at one level of explanation, the failure of public health theory identifies mistaken ideas and too narrow a vision. But these in turn require further explanation. The doctors who looked only at the last 150 years were educated people. Many studied the classics. They knew that history did not begin in nineteenth-century Europe. But earlier times somehow did not matter to them here. The rapid development of capitalism led to ideas about the unique novelty of our own time, immortalized by Henry Ford as “History is bunk.” They share American (and less extremely, European) pragmatism, an impatience with theory (in this case evolution and ecology). Therefore they did not see the commonality of plants and people as species among species. Ministries of health do not talk to ministries of agriculture. Agriculture schools are rural and state supported, their students often drawn from farm communities. Medical schools are urban and usually private, and their students come from the urban middle class. They do not fraternize or read the same journals. The pragmatism of both groups is reinforced by the sense of urgency to meet an immediate human need.

The development of a coherent epidemiology is thwarted by the false dichotomies that permeate the thinking of both communities: the either/ors of biological/social, physical/psychological, chance/determinism, heredity/environment, infectious/chronic, and others that we will discuss in other chapters.

One more level of explanation helps us understand the intellectual barriers that led to the epidemiological surprise. Narrowness and pragmatism are characteristic of the dominant ways of thought under capitalism, where the individualism of economic man is a model for the autonomy and isolation of all phenomena, and where a knowledge industry turns scientific ideas into marketable commodities—precisely the magic bullets that the pharmaceutical industry sells people. The long-term history of capitalist experience encourages those ideas that are reinforced by the organizational structure and economics of the knowledge industry to create the special patterns of insight and ignorance that characterize each field and make inevitable its own particular surprises.

3
False Dichotomies

Our understanding of nature is deeply constrained by the language we need in talking about it, a language that is itself the result, as well as the replicator, of long-standing ideological practice. All of science, even “radical” science, is plagued by dichotomies that seem unavoidable because of the very words that are available to us: organism/environment, nature/nurture, psychological/physical, deterministic/random, social/individual, dependent/independent. A remarkable fraction of the radical reanalysis of nature that we ourselves have engaged in has revolved around a struggle to cut through the obfuscations that have arisen from those false oppositions.

One aspect of the dichotomies of general/particular and external/internal is the relation betwe...