A unicorn is described as having the legs of a deer, the tail of a lion, the head and body of a horse. It possesses a single horn which is white at the base, black in the middle and red at the tip. Its body is white, its head red, and its eyes are blue. Clearly, the only thing unreal about a unicorn is in the combination of its parts. That is, a unicorn is less than the sum of its parts, assuming, that is (with a prayerful nod to Anselm of Canterbury), that existing in reality trumps existing in the mind, or in this case existing in the mind as in a series of disarticulated parts that are themselves very real.
When an ecosystem is described as greater than the sum of its parts, as it was in Eugene Odum’s holistic conception of it, what is meant is that when the biotic components of ecological communities interact with the abiotic realm (that is, the formerly living and the never-alive), certain properties of the whole emerge that cannot be readily predicted from an analysis of the component parts. This claim, made on behalf of the larger units of nature, was persuasive to generations of ecologists influenced by Odum’s textbook, first published in 1953 and now in its posthumously published 5th edition (2005).[1] However, in as much as Odum’s notion of the ecosystem manifests a Balance of Nature perspective it has almost universally fallen out of favor in ecology and, like the unicorn, is emphatically relegated to myth and fancy.
In one of a number of strenuous critiques of Odum’s holistic conception of the ecosystem, ecologist Dan Simberloff claimed that it resurrected one of ecology’s earliest and now discredited paradigms, the notion of the biotic community as a superorganism.[2] The superorganismic quality of the ecological community was a tenet of one of the first comprehensive theories in ecology where vegetation scientist Frederic Clements likened changes in the plant community over time to the developmental processes of organisms. The appeal of holistic ecosystem ecology with its Clementsian flavor was not, Simberloff argued, because it improved the science, but because it drew upon a myth of enduring appeal, one that derived from the metaphysical conceptions of the ancient Greeks. Less technically, one can say that holistic conceptions of ecology tap into a notion of the Balance of Nature – something, as we’ve seen contemporary ecologists choose not to defend.
