Such physiologically based preferences, called “epigenetic rules,” channel cultural transmission in one direction instead of another. By this means they influence the outcome of cultural evolution. It is here, through the physical events of cognition, that the genes act to shape mental development and culture.
The full cycle of gene-culture coevolution as we conceived it is the following. Some choices confer greater survival and reproductive rates. As a consequence, certain epigenetic rules, those that predispose the mind toward the selection of successful culturgens, are favored during the course of genetic evolution. Over many generations, the human population as a whole has moved toward one particular “human nature” out of a vast number of natures possible. It has fashioned certain patterns of cultural diversity from an even greater number of patterns possible.
Lumsden and I presented our scheme in several technical articles and two books.* The reviews were mixed; some were enthusiastic, but those in several key journals were unfavorable: Edmund Leach was enraged in Nature; Peter Medawar was contemptuous in the New York Review of Books; Richard Lewontin, by his own later description, was nasty in The Sciences. The subject of gene-culture co-evolution simply languished, mostly ignored by biologists and social scientists alike. I was worried, and puzzled. The critics really hadn’t said much of substance. Had we nevertheless failed at some deep level they saw but we failed to grasp? During the 1980s a handful of other researchers investigated the subject along conceptual pathways of their own devising. Gifted scientists with diverse expertise from genetics and anthropology, they included Kenichi Aoki, Robert Boyd, Luigi Cavalli-Sforza, William Durham, Marcus Feldman, Motoo Kimura, and Peter Richerson. They too met with only limited success, at least as measured by the spread and advance of the total research enterprise. Kimura, Japan’s foremost geneticist, told me that he had received almost no requests for his article on the subject.
It is possible that gene-culture coevolution will lie dormant as a subject for many more years, awaiting the slow accretion of knowledge persuasive enough to attract scholars. I remain in any case convinced that its true nature is the central problem of the social sciences, and moreover one of the great unexplored domains of science generally; and I do not doubt for an instant that its time will come.
*Jerre Levy, “Sex and the Brain,” The Sciences 21, no. 3 (1981): 20–23, 28
*Quoted in Ullica Segerstråle,’ ‘Whose Truth Shall Prevail? Moral and Scientific Interests in the Sociobiology Controversy” (Ph.D. diss., Department of Sociology, Harvard University, 1983).
*Richard C. Lewontin, Biology as Ideology: The Doctrine of DNA (New York: Harper Perennial, 1991), p. 107.
†Ibid.
‡R. C. Lewontin and R. Levins, “The Problem of Lysenkoism,” in Hilary Rose and Steven Rose, eds., The Radicalisation of Science (London: Macmillan, 1976), pp. 34, 59.
*C. J. Lumsden and E. O. Wilson, Genes, Mind, and Culture (Cambridge, Mass.: Harvard University Press, 1981) and Promethean Fire (Cambridge, Mass.: Harvard University Press, 1983). The summary of the theory of gene-culture coevolution presented here is drawn, with minor changes, from our article “Genes, Mind, and Ideology,” The Sciences 21, no. 9 (1981): 6–8.
chapter eighteen
BIODIVERSITY BIOPHILIA
IN 1980 THE EDITORS OF HARVARD MAGAZINE ASKED SEVEN Harvard professors to identify what they considered to be the most important problem facing the world in the coming decade. Four cited poverty arising from, variously, overpopulation, the influx of rural masses into cities, and capitalism. Another, focusing on the United States, cited the welfare state and excessive governmental control. The sixth chose the global nuclear threat.
None of these scholars mentioned the environment. None gave more than fleeting attention to the impact that problems of the 1980s might have on future generations. As the only natural scientist I chose a radically different subject, and a broader time scale: species are going extinct in growing numbers, I wrote; the biosphere is imperiled; humanity is depleting the ancient storehouses of biological diversity. I was thinking like an evolutionary biologist, in evolutionary time. “The worst thing that can happen, will happen,” I said, “is not energy depletion, economic collapse, limited nuclear war, or conquest by a totalitarian government. As terrible as these catastrophes would be for us, they can be repaired within a few generations. The one process ongoing in the 1980s that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats. This is the folly our descendants are least likely to forgive us.”*
This article marked my debut as an environmental activist. I was, I will confess now, unforgivably late in arriving. Biodiversity destruction had troubled my mind for decades, but I had made little overt response. In the 1950s, as I worked my way around bare red-clay gullies in Alabama and sought the vanishing rain forests of Cuba, I knew something was terribly wrong. My apprehension grew as I pored over the list of extinct and endangered animal species in the Red Data Books of the International Union for Conservation of Nature and Natural Resources. In the 1960s the picture darkened further when Robert MacArthur and I found that a reduction of habitat is inexorably followed by a loss of animal and plant species. Very roughly, we learned, a 90 percent reduction of forest cover—or prairie, or river course—eventually halves the number of species living there.
Adding to my concern was the Dream. It was literally an anxiety dream, and one that I occasionally experience to this day. I am on an island near an airport or in a town. I recognize the place immediately: from one night to the next, either Futuna or New Caledonia, both in the South Pacific. I’ve been there alone for weeks, and now, as my surroundings take increasingly detailed form, I remember that the hour of my departure is approaching. I realize that I have not examined the fauna and flora of the island, nor have I made any attempt to collect the ants, most of whose species remain unknown to science. I begin a frantic search for native forest. In the distance I see what looks like the edge of a copse and run to it, only to find a row of exotic trees planted as a windbreak, with more houses and fields stretching beyond. Now I am in an automobile. I speed down a country road; nothing but houses and fields appear on either side. There are mountains far to the north—in every dream always to the north. Perhaps some forest remains in the mountains. I fumble with a map and locate the access road, but I cannot go; my time has run out. The dream ends, and I awaken knotted with anxiety and regret.
Knowledge and dreams notwithstanding, I hesitated, confining myself in the waking world almost entirely to research and writing on other subjects. As the 1970s passed I wondered, at what point should scientists become activists? I knew from hard experience that the ground between science and political engagement is treacherous. I was gun-shy from the sociobiology controversy. Speak too forcefully, I thought, and other scientists regard you as an ideologue; speak too softly, and you duck a moral responsibility. I hesitated on the side of caution, taking some relief from knowledge that nonacademic organizations were already active in the conservation of biological diversity. They included the World Wildlife Fund and the International Union for the Conservation of Nature, global in their outlook and highly competent and respected. There was also the Organization for Tropical Studies, a consortium of universities and other institutions dedicated to the training of young biologists, which I had helped found in 1963. Many of these new professionals, I knew, were going into conservation science. I thought, let the next generation do it. Still, the movement needed the voices of senior biologists.
The decisive impetus for me came when, in 1979, the British ecologist Norman Myers published the first estimates of the rate of destruction of tropical rain forests. After adding up data country by country, he calculated the global loss of cover to be a little under one percent per year. This piece of bad news immediately caught the attention of conservationists around the world. The rain forests were and are of crucial importance as reservoirs of diversity. They teem wit
h the greatest variety of plants and animals of all the world’s ecosystems, yet at the time of Myers’ report they occupied only 7 percent of the world’s land surface. Their area was thus about the same as the contiguous forty-eight United States, and the amount of cover removed each year was about equal to half the area of the state of Florida. The reduction in area translated, in terms of the general relation between habitat area and diversity worked out in other ecosystems, to roughly one-quarter of a percent of species extinguished or doomed to early extinction each year. The cutting and burning appeared to be accelerating as a result of incursions by land-hungry rural populations and the increasing global demand for timber products.
Primed by Myers’ report, I was finally tipped into active engagement by the example of my friend Peter Raven. A distinguished scientist and director of the Missouri Botanical Garden, increasingly a public figure, Peter was determined and fearless. He had no qualms about activism. By the late 1970s he was writing, lecturing, and debating those still skeptical about the evidences of mass extinction. In 1980 he chaired a National Research Council study of research priorities in tropical biology, putting stress on the urgent problems of deforestation and biological diversity. More than anyone else Raven made it clear that scientists in universities and other research-oriented institutions must get involved; the conservation professionals could not be expected to carry the burden alone. One day on impulse I crossed the line. I picked up the telephone and said, “Peter, I want you to know that I’m joining you in this effort. I’m going to do everything in my power to help.” By this time a loose confederation of senior biologists that I jokingly called the “rain forest mafia” had formed. It included, besides Raven and myself, Jared Diamond, Paul Ehrlich, Thomas Eisner, Daniel Janzen, Thomas Lovejoy, and Norman Myers. We were to remain in frequent communication from then on.
A short time later I joined the Board of Directors of the World Wildlife Fund-U. S. and became their key external science adviser. I encouraged the staff to strengthen further their programs in scientific research while broadening the organization’s coverage to include entire ecosystems and not just individual star species such as the giant panda and bald eagle. I joined in promoting the “new environmentalism” being formulated within WWF. This more pragmatic approach combines conservation projects with economic advice and assistance to local populations affected by efforts to salvage biological diversity. Nature reserves, we knew and argued, cannot be protected indefinitely from impoverished people who see no advantage in them. Conversely, the long-term economic prospects of these same people will be imperiled to the degree that their natural environment is destroyed.
I lectured and wrote widely on the problems of ecosystem destruction and species extinction, and on possible socioeconomic solutions. In 1985 I published an article in the policy journal of the National Academy of Sciences titled “The Biological Diversity Crisis: A Challenge to Science,” which received widespread attention.* The following year I gave one of several keynote addresses at the National Forum on BioDiversity, held in Washington under the combined auspices of the National Academy of Sciences and the Smithsonian Institution. I then served as the editor of the proceedings volume, BioDiversity, which became one of the best-selling books in the history of the National Academy Press. The forum was the first occasion on which the word “biodiversity” was used, and after the publication of the book it spread with astonishing speed around the world; by 1987 it was one of the most frequently used terms in conservation literature. It became a favorite subject of museum exhibitions and college seminars. By June 1992, when more than a hundred heads of state met at the Earth Summit in Rio de Janeiro to debate and ratify global protocols on the environment, “biodiversity” approached the status of a household word. President Bush’s refusal to sign the Convention on Biological Diversity on behalf of the United States brought the subject into the political mainstream. Finally, the continuing controversies over the Endangered Species Act and the northern spotted owl made it part of American culture.
Biodiversity, the concept, has become the talisman of conservation, embracing every kind of living creature. So what exactly does it mean? The definition soon agreed upon by biologists and conservationists is the totality of hereditary variation in life forms, across all levels of biological organization, from genes and chromosomes within individual species to the array of species themselves and finally, at the highest level, the living communities of ecosystems such as forests and lakes. One slice of biodiversity among the near infinitude possible would be the variety of chromosomes and genes within one species of freshwater fish found in Cuba. Another would be all the freshwater fish species of Cuba, and still another would be the fishes and all other forms of life living in each river in Cuba studied in turn.
Because I edited the volume BioDiversity in 1988, it is widely thought that I also coined the term. I deserve no credit at all. The expression was put into play by Walter Rosen, the administrative officer of the National Academy of Sciences who organized the 1986 Washington forum. When Rosen and other NAS staff members approached me to serve as editor of the proceedings, I argued for “biological diversity,” the term I and others had favored to that time. Biodiversity, I said, is too catchy; it lacks dignity. But Rosen and his colleagues persisted. Biodiversity is simpler and more distinctive, they insisted, so the public will remember it more easily. The subject surely needs all the attention we can attract to it, and as quickly as possible. I relented.
I am not sure now just why I resisted the word at all, in view of the quickness with which it acquired both dignity and influence. After all, in 1979 I had invented a very similar term, “biophilia,” for use in a New York Times article on conservation.* Later, in 1984, I employed it as the title and pivotal idea of my book Biophilia. It means the inborn affinity human beings have for other forms of life, an affiliation evoked, according to circumstance, by pleasure, or a sense of security, or awe, or even fascination blended with revulsion.
One basic manifestation of what I called biophilia is a preference for certain natural environments as places for habitation. In a pioneering study of the subject, Gordon Orians, a zoologist at the University of Washington, diagnosed the “ideal” habitat most people choose if given a free choice: they wish their home to perch atop a prominence, placed close to a lake, ocean, or other body of water, and surrounded by a parklike terrain. The trees they most want to see from their homes have spreading crowns, with numerous branches projecting from the trunk close to and horizontal with the ground, and furnished profusely with small or finely divided leaves. It happens that this archetype fits a tropical savanna of the kind prevailing in Africa, where humanity evolved for several millions of years. Primitive people living there are thought to have been most secure in open terrain, where the wide vista allowed them to search for food while watching for enemies. Possessing relatively frail bodies, early humans also needed cover for retreat, with trees to climb if pursued.
Is it just a coincidence, this similarity between the ancient home of human beings and their modern habitat preference? Animals of all kinds, including the primates closest in ancestry to Homo sapiens, possess an inborn habitat selection on which their survival depends. It would seem strange if our ancestors were an exception, or if humanity’s brief existence in agricultural and urban surroundings had erased the propensity from our genes. Consider a New York multimillionaire who, provided by wealth with a free choice of habitation, selects a penthouse overlooking Central Park, in sight of the lake if possible, and rims its terrace with potted shrubs. In a deeper sense than he perhaps understands, he is returning to his roots.
Balaji Mundkur, an anthropologist and art historian at the University of Connecticut, has suggested a parallel explanation for another peculiarity of human taste: our fascination with snakes. These reptiles are among the features of mankind’s ancient environment for which people can easily acquire phobias. Other strong phobia inducers are spiders, wolves, heights, closed spaces, and runn
ing water. Just one frightening experience with snakes—as mild as a scary story—is enough to instill the aversion in a child. The fear experienced thereafter is marked by the onset of panic, nausea, and cold sweat, reactions of the autonomic nervous system beyond ordinary rational control. The responses are quickly acquired, yet strangely difficult to eradicate.
The highly directed reaction against snakes appears to have a genetic foundation. In evidence is the remarkable fact that people rarely acquire phobias toward the objects of modern life that are truly dangerous, such as guns, knives, electric sockets, and speeding automobiles. Our species has not been exposed to these lethal agents long enough in evolutionary time to have acquired the predisposing genes that ensure automatic avoidance.
People everywhere are not just repelled by snakes. They are fascinated by them, and if they can do so safely, they draw close to inspect them. Snakes are the wild animals that appear most often in dreams, and, designated as mystical serpents, in religious symbolism. Variously hybridized with humans or other animals, plumed, twinned, grown gigantic and swift and all-seeing, the dream-mutants are gods who both avenge and transmit wisdom according to the vagaries of mood and circumstance. The caduceus, the staff entwined by a pair of serpents and carried by Mercury as messenger of the gods, now serves as the emblem of the medical profession.
The ultimate source of our attention to snakes may be the same as that of the fear and fascination they excite in other primates: their deadly nature. Poisonous species occur throughout the world, in the Northern Hemisphere as far north as Canada and Finland, and are an important source of mortality in most places where people live close to natural environments. The chain of biophilic evolution, as I interpreted it in 1984 from Mundkur’s evidence, runs as follows. The deadliness of some kinds of snakes resulted through evolutionary time in an innate aversion and fascination among human beings. Hence they regularly disturb our dreams with ambiguous symbolism. Shamans and prophets report their own dreams as divine revelation and install the imagery in mythology and religion. From these sacred redoubts the glittering transformed serpent has invaded story and art.
Naturalist 25th Anniversary Edition Page 33