Monday, May 01, 2006

Natural Selection on Center Stage: Part Three

Here is more of Princeton University President Shirley M. Tilghman's George Romanes Lecture at Oxford University on 12/1/05. The speech entitled 'Strange Bedfellows: Science, Politics and Religion' is referenced at the following URL:

"A common weapon that is used to advance the "theory" of intelligent design is to posit that evolutionary biology cannot explain everything — that there remains uncertainty in the fossil record and that there is as yet no consensus on the origin or nature of the first self-replicating organisms. This, too, reflects a basic misunderstanding about how science works, for, in fact, all scientific theories, even those that are approaching 150 years of age, are works in progress."

[Bradford]: More accurately, advances in scientific knowledge are a continuing work in progress. Such advances can lend credence to a theory or detract from its credibility. The assumption that future knowledge favors a predetermined outcome indicates that objectivity has been compromised.

"Scientists live with uncertainty all the time and are not just reconciled to it but understand that it is an integral part of scientific progress. We know that for every question we answer, there is a new one to be posed. Indeed, the very word, "theory," is misunderstood by many who take it to mean an "idea" that has no greater or lesser merit than any other idea. The fact that Darwin's "ideas" on natural selection have stood the test of time through keen experimental challenge does not give his theory special status in their eyes."

[Bradford]: That lethal genetic changes are selected against is not in dispute. But where is experimental support for the concept that life arose through selected chemical outcomes or that universal metabolic pathways evolved through a selection process? How was a minimal genome selected and where is experimental support for the contention that the irreducibly complex translation function evolved? Add hundreds of other irreducibly complex biological systems to that list.

"There are also those who exploit the fact that scientists often disagree over the interpretation of specific findings or the design of experiments to argue that nothing is settled and thus anything is possible. The fact of the matter is that fierce disagreement is the stuff of scientific inquiry, and the constant give-and-take is needed to test the mettle of our ideas and sharpen our thinking. It is not, as many would claim, prima facie evidence for deep fissures in the central tenets of natural selection.

Of course, the real test of whether intelligent design is a scientific theory, comparable to Darwin's theory of natural selection and worthy of equal consideration in the biology classroom, is whether it poses testable hypotheses. Here the answer is self-evident — it does not — and therefore it has no place in the science curriculum of America's public schools, which rest on the premise that the state has no constitutional authority to impart supernatural truths."

[Bradford]: Let's take the last part first. What supernatural truth is revealed in the contention that the sequential order of nucleotides in nucleic acids, rather than their chemical composition, imparts their selective value? How is the position that this is relevant to whether a minimal genome would arise in a prebiotic environment, without intelligent input, a supernatural truth? There is nothing supernatural about DNA with encoding properties. There is however something amiss in assuming that on a planet devoid of both life and nucleic acids, an unspecifed series of chemical interactions not only led to the formation of nucleic acids but also to at least one with both encoding properties and a biochemical means to translate and replicate the same.

It is by no means "self-evident" that no testable hypothesis can be consistent with an intelligent design paradigm. One can devise counter hypotheses related to an identical biological system. An irreducibly complex system would consist of interacting proteins and their corresponding encoding genes. It could also be accompanied by a hypothesis as to how the component proteins sequentially evolved. Knock out encoding genes in a way consistent with their hypothesized evolution and place the organism (one with a high reproductive rate) in an environment conducive to the application of selective pressure for sufficient time. Observe the system evolve- or not do so. Back to the Tilghman speech-

"Rather than searching for explanations for the complexity that is surely present in each living organism, intelligent design accepts that this complexity is beyond human understanding because it is the work of a higher intelligence, leading logically to the conclusion that experimentation — the tried and true basis for scientific progress — is pointless. The result is an intellectual dead end."

[Bradford]: Baloney. ID does not claim that biological systems are beyond human understanding because they are the work of a higher intelligence as alleged. This kind of straw man promotes intellectual dishonesty. Who made this claim? Dembski? Behe? Stephen Meyer? IDers are as curious as anyone to uncover the unknown and are not excoriated because they differ as to the components of a biochemical pathway, the nature of a cellular system or anything of scientific significance. They are criticized for believing intelligence better explains the origin of particular biological systems. The impact of this is felt more in the realm of the philospophical than in science. Antagonism toward ID can also be traced to extra-scientific motives.

"In fact, because there is no prediction that can be tested, the future of intelligent design is dependent on the failure of experiments designed to test other hypotheses."

[Bradford]: Another misconception. If data is capable of supporting a paradigm that is dependent on the adaquacy of biological mechanisms to generate sufficient selected changes over long time eras then data that contravenes this is data that can be used to support an alternative paradigm.

Stephen Meyer cited numerous studies in his paper 'Intelligent Design: The Origin of Biological Information and the Higher Taxonomic Categories'1 to butress his points that proteins and their encoding genes are highly specified to their functional roles and correspondingly sensitive to loss of function caused by sequence alterations. Limitations on amino acid residue variation when combined with mutation rate data and evolutionary time frames can suggest that a design paradigm is more consistent with what we know. Meyer cited one study indicating loss of protein function invariably occured in cases involving multiple amino acid substitutions. Tilghman may claim such references illustrate a dependency on "failure of experiments" but the concern is not a failure of science to advance in knowledge but rather evidence of concern for a "failure" of data to support a preferred outcome.

More recently other papers have been published indicating data that supports an ID point of view. Richard Robinson's 'Mutations Change the Boolean Logic of Gene Regulation' (PLOS Biology) is an example.2 So is a steady stream of new discoveries related to "junk DNA." Junk DNA was a prediction formed from evolutionary expectations and based solidly on our ignorance rather than our knowledge. Back to Tilghman-

"It is ironic that intelligent design's reliance on negative proof exacerbates what religious historians have called the "shrinking God" problem. Each time a natural phenomenon that has been attributed to divine inspiration is explained by scientific exploration, the role for an intelligent designer is diminished. In other words, they are setting up God to fail."

[Bradford]: Now we are treated to the author's theological concern. It is also another straw man; a variation of the God of the gaps charge. Lack of knowledge as to how x occurs is the basis for a belief in a divine cause or so it goes. Actually most IDers, be they Christian Muslims or Jews, believe the universe functions in an orderly manner that was preordained by God. The implication being natural phenomenon operate this way independently of our knowledge. Attribution of divine causality is not dependent on scientific developments. That is not the same as saying that intelligence is indetectable. That's Ken Miller's position and he is entilted to his theology. What he and others are not entitled to is maintaining that scientific evidence precludes intelligence as a causal component of biological origins.

The "shrinking God" argument is a strange one. It's indicative of motive and a hidden one at that. If Darwinists wish to make the argument that either there is no God or that it is impossible to link natural phenomenon to intelligent causality then let them not hide behind science in doing so.




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