Biodiversity & Biotechnology
by Lorna Salzman
Earth Day 2000 comments to US Club of Rome
Having been asked to pick up some slack at the March 20 NYC meeting of the USA Club of Rome, I ventured into a mine field of my own making: hypothesizing a relationship between biodiversity and biotechnology. Soon after I began pondering this, my tendency to resort to Darwin and evolutionary theory paid off and the proverbial light bulb lit up. It was as if Theodosius Dobzhansky's famous statement had been incarnated: " Nothing in biology makes sense except in the light of evolution".
Since biotechnology involves the manipulation of genetic material (DNA), it seemed obvious to me that the field of transgenics - the insertion of a gene from one species into the genome of an unrelated species - was seriously meddling in the evolutionary process by which all living things have come into being. Instinctively I sensed that transgenic biotechnology is profoundly counter-evolutionary. To understand why it is necessary to understand the reason for and importance of biological diversity, and to understand an important fundamental truth: biological diversity is both the prerequisite for and result of evolution.
Biodiversity exists on several levels, and at least four of these stand out: genetic diversity, population diversity, species diversity and ecosystem diversity. Genetic diversity lies within the genome, the full complement of genes possessed by each living thing. The genome of no two individuals is alike (save identical twins).Such diversity provides a hedge against catastrophic environmental change, insuring that some individuals will have the capacity to survive such change. These variants confer greater fitness on the individuals possessing them, enabling them to survive and reproduce more successfully. Genetic diversity provides the basic components for evolution to occur.
Population diversity is really genetic diversity write large, or species diversity writ small. A population is a distinct subgroup within a species which may share particular traits not manifested by other populations, but together all populations manifest the genetic diversity of that species. Because populations vary genetically and in their ability to adapt to the environment, they are a kind of insurance policy for the species as a whole. If a cataclysm occurs, the existence of numerous populations in a species makes it likely that at least one will survive. Thus, in order to save species, we need to save its individual populations.
Ecoystem diversity means having a diversity of systems that perform important ecological services, and whose components not only contribute to that system but interact with each other. Often ecosystem components are symbiotic with other organisms, and sometimes they are co-dependent or co-evolved with them, to the point where the survival of each one depends on that of the other. These systems also contain flagship or indicator species, without which that system would not exist or function. When one recognizes this hierarchy of types of biodiversity, one fact becomes clear: that the most urgent task before us is the maintenance of unimpaired evolutionary processes and the ecological viability of populations.
But the threats to all types of biodiversity are grave. They include pollution, disease, overharvesting, invasive alien species, habitat fragmentation and habitat destruction. Virtually all of these are human induced or a result of human activities. Habitat destruction is, however, the most definitive factor in reducing biodiversity because a species only exists within a biotic community or ecosystem and within the relationships to its neighbors, predators and prey. Outside of these, as in zoos, it really is just an artifact. Once a species' home is destroyed, it has nowhere else to go. Its numbers decline into what is called a population bottleneck, with too few breeding individuals, and so does its genetic diversity, leaving it vulnerable to deformities, defects and disease as a result of inbreeding. Thus, it is crucial to maintain enough habitat to maintain enough populations so as to preserve the evolutionary potential of that species to survive and reproduce. You don't save species; you save habitats.
Thus, the loss of biodiversity is a devastating blow against the process of evolution, because it reduces the raw materials needed for natural selection to operate. Once genetic and population diversity are lost, remaining populations are fewer and more vulnerable to environmental change. It is very much like a bunch of twigs; a large bundle is almost impossible to break but a handful is easily snapped in two.
So I will move now to biotechnology and genetic engineering. Not all biotechnology involves transgenics, the transfer of genetic material from one species to another. Much of it has medical applications involving human disease. But here there is also more than one kind: somatic and germ cell. Medical intervention involving body cells (somatic) is quite different from that involving the germ cells or gametes. The former can theoretically mitigate or cure a defect in a single individual but is not passed on to future generations. The latter, however, involves the germ line, and changes made to gametes are indeed passed on forever. This is in essence a revival of eugenics, which would allow the social and behavioral engineering of our descendants - literally "designer genes". But even somatic medical intervention is risky because it would tend to promote the notion that those who possess some defect or condition are somehow inferior to other people.
Transgenics now are being applied to non-human animals and plants, mainly by agro-chemical corporations for the purposes of controlling seeds and food supplies. Because of meretricious patent laws, those who make a change in the genetic makeup of a particular plant or animal are considered to have created a "novel" organism and are entitled to control and uses of that organism. So agro-chemical corporations are moving full speed ahead to take control of the major food crops of the earth by "improving" these through transgenics that in theory are more productive, resistant to pests, contain more vitamins, etc. Such things have always been done over millennia by traditional breeding methods in which farmers could breed varieties of the same species that were well suited to local climate, soil and hydrology (land races). In Peru over 800 varieties of potatoes have been developed, each of which has different traits than the others. The same is true of Asian rice varieties. All of these worked within the constraints and opportunities of evolution and natural selection, without crossing genomic and species boundaries.
But transgenic technology in effect bypasses evolution and replaces natural selection with artificial human selection. Instead of developing local strains and varieties to meet local conditions, genetic food scientists are inserting genes from alien species in order to make the plant resistant to pests or to cold, or more particularly to pesticides and herbicides. This kind of resistance means that agrochemicals can be broadcast amply and freely over fields to kill weeds but the food crop will not be killed. However, it is not as simple as this because natural selection ultimately triumphs as the most resistant weeds survive the spray, reproduce and pass on their chemical resistance to future generations so that hardy weeds can multiply prolifically. Meanwhile, pesticide resistance genetically engineered into food crops quickly finds its way off site as pollen blows far away and pollinates wild relatives who then become resistant themselves. This is especially true of rapeseed(canola) which is in the large mustard family.
Antibiotic resistance may be the Black Plague of the 21st century, as a result of transgenics. When a foreign gene is inserted into another species, it is accompanied by an antibiotic "marker gene" which tells the scientists whether the foreign gene has successfully been implanted. But that marker gene doesnt disappear. It is now incorporated into the genome of the second species. And if this is a plant species, it is sooner or later ingested by insects, butterflies, bees, who as pollinators are at the bottom of a food chain. In Germany bacteria and fungi in the stomachs of honeybees were found to contain a gene that had been inserted into a genetically engineered rapeseed (canola) plant, something scientists denied could ever occur. We already know that antibiotic resistance is one of the most serious health problems we face today; tuberculosis and malaria have become resistant to almost all the drugs formerly used to treat them. The antibiotic marker genes in genetically modified food can only exacerbate this problem.
The problem of alien species was mentioned earlier. Alien species brought from abroad enter an environment free of predators and enemies, and thus have a competitive reproductive advantage. They can colonize habitats and ecosystems freely, and are almost impossible to extirpate. The list of these is long: purple loosestrife, Lantana, Kudzu, Asian beetles, zebra mussels, meloleuca trees, starlings and more.They take over lakes, marshes, forests, roadsides and nest holes, outcompeting native species and running rampant, destroying landscapes and impairing the functioning of natural systems, which can deteriorate or disappear, taking all their component species with them.
In effect, transgenics creates alien species. By introducing foreign genetic material into the genome of an entirely different species, genetic scientists and chemists are literally creating new life forms that never existed, which never appeared through the evolutionary process, but now exist thanks to the circumventing of evolution and natural selection. Because of the absence of any evolutionary history or relationships in the new environment, and because the effect of inserting one gene into a genome cannot be predicted, transgenics creates potential monsters . No one knows whether the transplanted gene will function, or, more important, how and where it will function as part of the genome. A worst-case scenario would envision creating a new organism with a malevolent ecology for which no control can be found, a genetic monster outcompeting its neighbors, reproducing uncontrollably like an alien plant species, or coding for a lethal protein, a chimera that can never be recalled or dissolved. It is truly science fiction brought to life. Genetic pollution, unlike that from chemicals, remains forever...and reproduces forever.
Now let us go back to the original hypothesis linking biodiversity with biotechnology. What does the loss of biodiversity have in common with genetic engineering, in particular transgenics? In a word, simplification. We have already learned the severe drawbacks of monocrop culture, which clears away all natural vegetation to create vast acreage of a single crop which, in turn, becomes a hearty feast for pests, blights and climatic aberrations, and which then necessitates newer and more powerful chemical poisons, on an eternal treadmill to compensate for the increasingly resistant insects and fungi.
In the case of biodiversity the destruction of habitat means that populations decline, the availability of different genomes is severely reduced, species are reduced to small numbers vulnerable to disease and inbreeding, ecosystem functions falter and fail, and an ecological void or desert is the result. In the case of biotechnology, human needs and objectives replace the process of evolution through natural selection by creating a genetic artifact on a large scale in place of the genomic variation that is normal to all species. Instead of a single crop, genetic scientists have focused on a single new gene to their narrow specification - enhanced growth, freeze or disease resistance, rejecting all the other offerings of evolution. Thus, both industrial monocrop agriculture and transgenics reject everything but their single product. This is simplification carried to a deadly extreme. It is precisely the opposite of what evolution intends and offers us. Transgenics stops evolution in its tracks and re-directs it, following the orders of corporations and genetic engineeers. And though we are all passengers none of us know where we are headed.