total descendants::1 total children::1 |
ale oplati sa to precitat cele C. GMOs in detail The systemic global impacts of GMOs arise from a combination of (1) engineered genetic modifications, (2) monoculture—the use of single crops over large areas. Global monoculture itself is of concern for potential global harm, but the evolutionary context of traditional crops provides important assurances (see Figure 8). Invasive species are frequently a problem but one might at least argue that the long term evolu- tionary testing of harmful impacts of organisms on local eco- logical systems mitigates if not eliminates the largest potential risks. Monoculture in combination with genetic engineering dramatically increases the risks being taken. Instead of a long history of evolutionary selection, these modifications rely not just on naive engineering strategies that do not appropriately consider risk in complex environments, but also explicitly reductionist approaches that ignore unintended consequences and employ very limited empirical testing. Ironically, at a time when engineering is adopting evolu- tionary approaches due to the failure of top-down strategies, biologists and agronomists are adopting top-down engineering strategies and taking global systemic risks in introducing organisms into the wild. One argument in favor of GMOs is that they are no more "unnatural" than the selective farming our ancestors have been doing for generations. In fact, the ideas developed in this paper show that this is not the case. Selective breeding over human history is a process in which change still happens in a bottom-up way, and can be expected to result in a thin-tailed distribution. If there is a mistake, some harmful variation, it will not spread throughout the whole system but end up dying out due to local experience over time. Human experience over generations has chosen the biological organisms that are relatively safe for consumption. There are many that are not, including parts of and varieties of the crops we do cultivate [12]. Introducing rapid changes in organisms is inconsistent with this process. There is a limited rate at which variations can be introduced and selection will be effective [13]. There is no comparison between tinkering with the selec- tive breeding of genetic components of organisms that have previously undergone extensive histories of selection and the top-down engineering of taking a gene from a fish and putting it into a tomato. Saying that such a product is natural misses the process of natural selection by which things become “natural." While there are claims that all organisms include transgenic materials, those genetic transfers that are currently present were subject to selection over long times and survived. The success rate is tiny. Unlike GMOs, in nature there is no immediate replication of mutated organisms to become a large fraction of the organisms of a species. Indeed, any one genetic variation is unlikely to become part of the long term genetic pool of the population. Instead, just like any other genetic variation or mutation, transgenic transfers are subject to competition and selection over many generations before becoming a significant part of the population. A new genetic transfer engineered today is not the same as one that has survived this process of selection. An example of the effect of transfer of biologically evolved systems to a different context is that of zoonotic diseases. Even though pathogens consume their hosts, they evolve to be less harmful than they would otherwise be. Pathogens that cause highly lethal diseases are selected against because their hosts die before they are able to transmit to others. This is the underlying reason for the greater dangers associated with zoonotic diseases—caused by pathogens that shift from the host that they evolved in to human beings, including HIV, Avian and Swine flu that transferred from monkeys (through chimpanzees), birds and hogs, respectively. More generally, engineered modifications to ecological sys- tems (through GMOs) are categorically and statistically dif- ferent from bottom up ones. Bottom-up modifications do not remove the crops from their long term evolutionary context, enabling the push and pull of the ecosystem to locally extin- guish harmful mutations. Top-down modifications that bypass this evolutionary pathway unintentionally manipulate large sets of interdependent factors at the same time, with dramatic risks of unintended consequences. They thus result in fat-tailed distributions and place a huge risk on the food system as a whole. For the impact of GMOs on health, the evaluation of whether the genetic engineering of a particular chemical (protein) into a plant is OK by the FDA is based upon consid- ering limited existing knowledge of risks associated with that protein. The number of ways such an evaluation can be in error is large. The genetic modifications are biologically significant as the purpose is to strongly impact the chemical functions of the plant, modifying its resistance to other chemicals such as herbicides or pesticides, or affecting its own lethality to other organisms—i.e. its antibiotic qualities. The limited existing knowledge generally does not include long term testing of the exposure of people to the added chemical, even in isolation. The evaluation is independent of the ways the protein affects the biochemistry of the plant, including interactions among the various metabolic pathways and regulatory systems— and the impact of the resulting changes in biochemistry on health of consumers. The evaluation is independent of its farm-ecosystem combination (i.e. pesticide resistant crops are subject to increased use of pesticides, which are subsequently present in the plant in larger concentrations and cannot be washed away). Rather than recognizing the limitations of current understanding, poorly grounded perspectives about the potential damage with unjustified assumptions are being made. Limited empirical validation of both essential aspects of the conceptual framework as well as specific conclusions are being used because testing is recognized to be difficult. We should exert the precautionary principle here – our non- naive version – because we do not want to discover errors after considerable and irreversible environmental and health damage. |
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