Hi all
We frequently hear beekeepers claim that "natural selection" is the ideal way to bring about the best bees, that the wisdom of nature is vastly better than humankind, that "everything works if you let it," ad nauseum. When scrutinized with a clear eye, these concepts fall far short. Here is an excerpt from an essay on "DARWINIAN AGRICULTURE" by R. Ford Dennison of UC Davis:
SHOULD AGRICULTURE MIMIC NATURE?
The argument for mimicking natural ecosystems is unclear. Natural ecosystems may have "withstood the test of evolutionary time" but the test criteria were not stated explicitly. No natural terrestrial ecosystem has exported as much human food per hectare, over millennia, as rice fields in Asia. Some agricultural ecologists appear to assume that natural ecosystems somehow have been optimized, perhaps by natural selection. Others apparently assume that natural selection operates, if not for the benefit of an entire ecosystem, at least for the benefit of a species as a whole. Most evolutionary biologists, however, would reject these assumptions as inconsistent with modern evolutionary theory.
Individual plants and animals contain genes that have repeatedly passed through the screen of natural selection, but has anything analogous to natural selection also improved the structure and function of the ecosystems where those species live? Even the few evolutionary biologists who think natural selection may operate on groups of plants generally agree that natural selection is unlikely to consistently improve ecosystem function, when the collective interests of species in the ecosystem are in conflict with individual competitiveness.
But do undisturbed natural ecosystems actually excel in those functions relevant to agriculture, such as the ability to export food sustainably? The greater year-to-year stability of nut production by almond orchards (7,500 to 12,800 kg/ha) relative to oak forests (0.4 to 55 kg/ha) seems inconsistent with this. In one study, total seed yield of native prairie ranged from 7 to 525 kg/ha over three years (Brown 1943), a small fraction of the 1988 average world grain yield of 2480 kg/ ha. We consider it unlikely that natural ecosystems will consistently outperform agricultural systems, by most agricultural criteria.
We conclude that "Nature’s wisdom" resides mainly in the sophisticated adaptations of individual plants and animals, not in ecosystem structure. Any given feature of a natural ecosystem may be there "for a reason," in the same sense that earthquakes happen for a reason, but that does not mean they are there for a purpose. Mindless mimicry of natural ecosystems reveals ignorance of, not respect for, ecological principles.
Denison, R. F., Kiers, E. T., & West, S. A. (2003). Darwinian agriculture: when can humans find solutions beyond the reach of natural selection?. The quarterly review of biology, 78(2), 145-168.
Contributed by PLB
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