Sunday, August 06, 2006

Part II: How is Darwinian Evolution Connected to Natural Resource Management?

(Here is Part II of the article I wrote concerning the relationship of natural resource management with evolution (. Remember, it was written with a general audience in mind. Commenters on Part I have already pointed out some of the glaring errors of IDT, but my intent was to start with the premise that IDT is valid and then ask the question later, IF it is valid, THEN it should have some bearing on basic aspects of every day science such as determining whether land management agencies use prescribed fire or "thin from below". This is part where I start to show that the emperor has no clothes...).

Was Darwin Right? And Should the Forest Service Care?

Part II: How is Darwinian Evolution Connected to Natural Resource Management?

There can be no mistake that natural resource management is based on Darwinian evolution. Pick up any major scientific journal covering forestry ecology and management issues and it becomes readily apparent that the contents are imbued with Darwin’s ideas, although the connection may not be obvious to the lay reader. Terms like “natural selection” and “evolution” are likely to be absent, and even Darwin’s name will be missing from most articles. In several randomly picked articles from recent (2005 or in press) issues of Forest Ecology and Management, I noted that the terms “Darwin”, “evolution” or “natural selection” occur only three times. However, terms like “adaptation”, “competition”, “differential reproduction”, “variability”, “mutation”, “mortality” and “survival” are mentioned in abundance. These are principles of evolutionary biology and depend on the broader concepts of Darwinian evolution in order to make sense. “Adaptation”, for example, has no biological meaning outside of an evolutionary context. I found these evolutionary principles further codified in more colloquial management language that also frequents research articles on which agency officials depend: “shade tolerant”, “fire-dependent”, “historical trajectory”, “best fit to existing conditions”, “trajectory of forest types”, “selective harvesting”, “fires favor the largest trees with the thickest bark”. The list goes on. These are clearly describing management applications of variability, competition, differential survival and reproduction, all bedrock principles of evolutionary theory. The language of forest management belies its Darwinian framework.

In an effort to be fair to IDT advocates I limited my perusal of resource management articles to those that had clear management implications and did not already clearly invoke evolutionary principles in their titles or abstracts. In reality, it is difficult to find examples of forest management research that do not explicitly invoke evolutionary assumptions. My point is that research articles not explicitly stating their evolutionary framework are clearly still assuming Darwinian principles to discuss management practices that would give us healthier forest resources. The research and management arms of the USDA Forest Service and other agencies tasked with land and species management cannot escape Darwin’s legacy.

But what of IDT as an alternative to Darwinian evolution? If IDT is a scientifically valid theory on a par with evolution, as its advocates insist, then what implications would this idea have for forest management? What mechanisms does IDT purport to offer as replacements for evolutionary theory? The problem is divining what IDT really is. Even allowing IDT the benefit of the doubt as a scientific proposal this is no easy task. Amongst ID proponents there is no consistent definition as to what IDT looks like as a scientific endeavor. Components of IDT are often criticized as a “moving target”, and clearly with justification. IDT proponents seem to generally accept the idea that species have a history and have changed through time; however, this position is not always clear. Many IDT advocates accept this premise for some species but are uncomfortable applying it to others (there seems to be no problem that camels exhibit an evolutionary trajectory, but there appears to be some discourse over whether the same can be said for humans). Some reject it outright. There is also some suggestion that this component of IDT is largely a fa├žade, made to make IDT more palatable as a scientific idea and to avoid entanglements with religious ideas of creationism that are rejected by the court system.

Assuming IDT accepts Darwin’s concept of “descent with modification”, what it probably does not accept is its mechanism, although here again IDT is a moving target. IDT proponents appear to largely reject natural selection as a mechanism driving species change, suggesting that life particularly at the cellular level is too complex to have been derived by “natural” mechanism such as Darwinian selection. Many biological structures are considered “irreducibly complex” in that if one component is removed the system completely stops functioning. Given the apparent complexity of some biological structures, natural selection would have had to create the entire sequence with all of its parts in a single event. Or so the argument assumes. Clearly, they argue, natural selection is incapable of such a feat. Instead they suggest creation of species is guided, at least at some level, by an undefined Designer, and not through Darwinian natural selection. If natural selection is inherently flawed, as IDT proponents suggest, then concepts of adaptation, competition, and variability have no useful application under IDT. Natural resource management strategies essentially become nothing more than “shot in the dark” efforts.

IDT advocates would probably counter that some combination of natural selection mechanisms and IDT principles is possible, but again they offer nothing more than another moving target, against which it is impossible to draw testable hypotheses. That still begs the question of exactly where in the natural system mechanisms are thwarted by intelligent design imposed from above. IDT may or may not accept a historical relationship between species and it may reject natural selection as a mechanism driving species change, but either way IDT cannot describe functional relationships among living organisms that exist in absence of natural selection. IDT proponents are not specific about the instances, locations and conditions under which Darwinian mechanisms are overridden by Designer intervention, because the idea is immune from testable propositions.

Instead, IDT’s main argument falls on criticism of evolutionary theory. They constantly repeat the mantra: many biological features are irreducibly complex and cannot be the product of natural selection; the Cambrian explosion indicates the sudden occurrence of major animal body plans that cannot be explained by Darwinian principles; and no transitional fossils exist in the paleontological record to indicate species change as the result of an accumulative process like natural selection. Irreducible complexity seemed to initially catch the evolutionary research community off-guard when it was proposed in the early 1990s, but only for a moment. Solid research has since demonstrated time and again that supposed irreducibly complex systems can be reduced further and easily explained by natural selection. Components of supposed irreducible biological systems are now found to function quite well without some parts of the system, find “short-cut” pathways to accomplish the same function, or simply serve other functions. IDT activists have covered up the paleontological reality of the Cambrian explosion to give the impression that birds, reptiles, mammals, fish and insects arose suddenly some 500 million years. Not only did the so-called “explosion” last for tens of millions of years, but new research in the Pre-Cambrian period is showing a steady rise of complex features in organisms. Further, IDT advocates purposefully (or ignorantly) misuse the term “body plan”: no birds, no mammals, no insects, no reptiles and no fish are to be found in the Cambrian. These “groups” as we know them today all arise much later in time, their fossil histories marked in many cases by clear transitional steps. The suite of transitional fossils familiar to paleontologists in all areas of research belies the claim made by IDT advocates that none exist. The pine tree forests managed by the Forest Service are just such an example. The fossil record shows transitional steps from their origin in the Jurassic some 150 million years ago. Their slow accumulations of characters adaptive to drier (and more fire prone) ecosystems is clear. The fact that managers today take advantage of those adaptive characteristics is testament to the fact that evolutionary theory offers practical applications for ecosystem restoration and restoration of “healthy” forests. In contrast, IDT offers resource management nothing of practical value.

I have attempted to give IDT the benefit of the doubt as a scientific endeavor on a par with evolutionary theory as its advocates would like. It is clear, however, that IDT proponents cannot answer basic questions about their supposed theory, because there is nothing about ID for which one can form testable hypotheses. It violates a primary requirement of theory: that it generate testable hypotheses to determine its ability to explain natural phenomena. Its proponents will cry foul and claim a bias against IDT bordering on abject prejudice, simply because it has religious connotations. But the reality is that IDT is not science. IDT exists not because it has advanced scientific knowledge but because its proponents have waged a successful public relations campaign (much like astrology). It has used popular dislike of evolution and manufactured “controversies” in evolutionary theory to camouflage its lack of a scientific approach and inability to offer anything of scientific value.

1 comment:

Health News said...

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