Which one is different: gravity, continental drift or evolution?
|October 29, 2010||Posted by vjtorley under Intelligent Design|
Newton’s theory of gravity, Wegener’s theory of continental drift and Darwin’s theory of evolution all have one thing in common: they have all been ridiculed as impossible at one time or another, because they lacked a plausible mechanism. So which theory is different from the rest? I shall argue that Darwin’s theory is unique, in that it has won widespread acceptance despite the existence of weighty scientific arguments showing that its mechanism is incapable of accounting for the phenomena that it purports to explain. However, if Darwin had formulated his theory of evolution in the same way that Newton formulated his theory of gravity, Darwin’s theory would have been invulnerable to these scientific difficulties. It is also a curious fact that although Darwin’s original theory has undergone radical transformation, like those of Newton and Wegner, many scientists and philosophers are proud to call themselves “Darwinists,” whereas no modern scientist would refer to him/herself as a “Newtonian” or “Wegnerian.”
In this short essay, I also address the fierce resistance in scientific circles to teaching Intelligent Design in high school classrooms, and I propose a legal strategy for neutralizing the Darwinian crusade.
Newton’s theory of gravity
In ancient times, gravity was viewed not as an external force acting on bodies, but as an inherent tendency of heavy bodies to fall towards the center of the universe. Experimental evidence in the sixteenth and seventeenth centuries overturned the traditional view. The first modern attempt to formulate a systematic theory of gravity was that of Isaac Newton (1642-1727).
From the very beginning, Isaac Newton realized that his theory of gravity, while empirically valid, lacked a plausible physical mechanism, as it seemed to require action at a distance. In his fourth letter to Richard Bentley (dated February 25, 1692/3), he wrote: “It is inconceivable that inanimate brute matter should, without the mediation of something else which is not material, operate upon and affect other matter, without mutual contact, as it must do if gravitation in the sense of Epicurus be essential and inherent in it. And this is one reason why I desired you would not ascribe ‘innate gravity’ to me. That gravity should be innate, inherent, and essential to matter, so that one body may act upon another at a distance, through a vacuum, without the mediation of anything else, by and through which their action and force may be conveyed from one to another, is to me so great an absurdity, that I believe no man who has in philosophical matters a competent faculty of thinking can ever fall into it. Gravity must be caused by an agent acting constantly according to certain laws; but whether this agent be material or immaterial, I have left to the consideration of my readers.” (Emphasis mine – VJT.)
To make matters worse, Newton’s theory assumed that gravity propagated instantaneously across space: each particle responds instantaneously to every other particle, regardless of the distance between them. Small wonder then, that to some of his contemporaries, Newton’s theory made gravity sound like a spooky, occult force. Indeed, according to two of his friends, Nicolas Fatio de Duillier and David Gregory, Newton himself seems to have thought at one time that gravitation was based directly on the will of God (Van Lunteren, F. (2002), “Nicolas Fatio de Duillier on the mechanical cause of Gravitation”, in Edwards, M.R., Pushing Gravity: New Perspectives on Le Sage’s Theory of Gravitation, Montreal: C. Roy Keys Inc., pp. 41–59); while on two other occasions (in 1675 and 1717), Newton tried to explain the action of gravity in terms of basic mechanical processes propagating through the aether, thereby avoiding the need for action at a distance.
Since he was unable to experimentally verify the motion that produces gravity, Newton wisely refused to link his theory of gravity to any scientific hypothesis as to the cause of this mysterious force. In his General Scholium of 1713, which was published in the second edition of Newton’s Principia, he wrote: “I have not yet been able to discover the cause of these properties of gravity from phenomena and I feign no hypotheses… It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies, and of our sea.” (Emphasis mine – VJT.)
Although Newton’s theory of gravity has been rendered obsolete by Einstein’s general theory of relativity, which was first proposed in 1915, Newton’s theory continues to be widely used because of its mathematical convenience and the fact that it works satisfactorily in normal circumstances, at velocities well below that of light.
Wegener’s theory of continental drift
Although the notion that continents drift was first suggested as far back as 1596, the German scientist Alfred Wegener was the first to formally publish the hypothesis that the continents had somehow moved apart, in 1912. He expanded on his ideas in his 1915 book, The Origin of Continents and Oceans. Wegener marshaled a great deal of evidence for continental drift in his book. However, most geologists found his theory unpersuasive, as it lacked a plausible mechanism. As we have seen, Newton’s theory of gravity also lacked a mechanism, but at least it was supported by observational evidence. Wegener, unlike Newton, was unable to point to observations showing that the continents are currently drifting, and it was not until 1984 (some fifty-four years after Wegener’s death) that NASA was able to release the first direct measurements of continental drift, showing that the Atlantic is gradually widening, and that Australia is receding from South America and heading for Hawaii.
To make matters worse, the mechanisms proposed by Wegener in his book were nowhere near powerful enough to move the continents. As Stephen Jay Gould narrates in his essay, The Validation of Continental Drift (in Ever Since Darwin: Reflections in Natural History, 1977, W. W. Norton & Co. Inc.):
All the original drifters [proponents of continental drift – VJT] imagined that continents plow their way through a static ocean floor. Alfred Wegener, the father of continental drift, argued early in our century that gravity alone could put continents in motion. Continents drift slowly westward, for example, because attractive forces of the sun and moon hold them up as the earth rotates underneath them. Physicists responded with derision and showed mathematically that gravitational forces are far too weak to power such a monumental peregrination. So Alexis du Toit, Wegener’s South African champion, tried a different tack. He argued for a local, radioactive melting of oceanic floor at continental borders, permitting the continents to glide through. This ad hoc hypothesis added no increment of plausibility to Wegener’s speculation. Since drift seemed absurd in the absence of a mechanism, orthodox geologists set out to render the impressive evidence for it as a series of unconnected coincidences.
In the end, writes Gould, “the classical data for drift … played no role in validating the notion of wandering continents; drift triumphed only when it became the necessary consequence of a new theory.” That theory was plate tectonics. As far back as 1920, the English geologist Arthur Holmes had proposed that plate junctions might lie beneath the sea, and in 1928, he had suggested that convection currents within the mantle might be the driving force. But what finally swung geologists behind the theory of plate tectonics was the publication of several scientific papers between 1965 and 1968, which defined the key concepts of the theory and which modeled the Earth’s surface as a set of a dozen or so moving plates. The all-embracing explanatory power of the new theory made it immensely attractive to scientists. Continental drift, in turn, was “demoted” from being a theory in its own right to a mere entailment of the new theory of plate tectonics.
Darwin’s theory of evolution
Darwin’s theory of evolution by means of natural selection was not the first scientific theory of evolution to be proposed, but it was by far the best-argued. In his monumental work, The Origin of Species, Darwin not only put forward his case for evolution by natural selection; he also anticipated scientific objections to his theory and attempted to rebut them.
The reaction to Darwin’s book was varied, but there was a widespread feeling that he had overstated his case. While many of Darwin’s scientific contemporaries were willing to affirm common descent, they were far more skeptical of Darwin’s claim that the driving mechanism was natural selection, acting on random variation.
Perhaps the most penetrating critique of Darwin’s views was Fleeming Jenkin’s Review of The Origin of Species, published in The North British Review, June 1867, 46, pp. 277-318. (Warning: Jenkin’s views on racial equality are odious and very much the product of their era.) Despite his disagreement with Darwin’s theory, Jenkin admitted to “feeling the greatest admiration both for the ingenuity of the doctrine and for the temper in which it was broached.” However, Jenkin argued that the theory was mistaken for several reasons:
(i) the variation possible within each species of plant and animal is limited and not infinite, so there is a limit to how far evolution can go;
(ii) within each species, there is a strong counter-evolutionary tendency for individuals to revert to the norm;
(iii) the fact that natural selection can improve existing organs within a species does not imply that it can create or develop new organs, or that it can generate new species;
(iv) even if abnormal variations (sports) are capable of generating new organs or habits, the traits would subsequently be diluted by interbreeding with individuals lacking the new trait;
(v) whereas Darwin’s theory requires countless ages during which the earth was habitable, the scientific evidence from thermodynamics and the cooling of the stars suggested that the Earth is no more than a few hundred million years old; and
(vi) contrary to what Darwinists assert, it is not particularly surprising that species can be arranged in a graduated series, with numerous intermediates, as all animals are constituted from combinations of the same basic body parts.
Another criticism of Darwin’s theory was voiced by the anatomist St. George Mivart, who argued that natural selection could not explain complex structures such as the eye, since they would only be beneficial (and selectable) when fully formed. Darwin was certainly alive to this objection, which he attempted to rebut by pointing out that the eyes of organisms living today exhibited varying grades of complexity, forming a series.
Darwin’s theory of evolution: the current state of the evidence
Discoveries in genetics have rendered moot Jenkin’s fourth objection to Darwinism (which Darwin regarded as the most telling one, against his theory), and geologists now agree that the Earth is about 4.5 billion years old. Additionally, the existence of (mutually consistent) nested hierarchies in the genetic and anatomical traits of organisms lends strong support to the hypothesis that all living things share a common ancestry. Fossil evidence of intermediates remains sparse, but is consistent with the family tree that scientists have constructed from the nested hierarchies of traits found in organisms.
Having said that, Jenkin’s first three objections continue to retain their force today, as does St. George Mivart’s argument relating to the emergence of complex structures. Indeed, the strength of these objections has increased during the 140 years since they were first voiced.
I was especially struck by this when listening to the recent radio debate between Professor Michael Behe and Professor Keith Fox. Time and time again, Behe put forward experimental evidence demonstrating the causal inadequacy of natural selection, which large-scale experimental trials have shown to be incapable of generating complex structures in organisms. He also cited a recent scientific paper entitled A golden age for evolutionary genetics? Genomic studies of adaptation in natural populations by N.J. Nadeau and C.D. Jiggins (Trends in Genetics, November 2010; 26(11):484-92. Epub 2010 Sep. 28) in which the authors admit that “most studies of recent evolution involve the loss of traits, and we still understand little of the genetic changes needed in the origin of novel traits.”
Additionally, in his recent book, The Edge of Evolution (Free Press, 2007), Professor Michael Behe has argued that the scientific evidence to date suggests strongly that there is a biological limit to how far evolution by natural selection can transform populations of organisms. Certainly, it can create new biological species and probably new genera, but as Behe argues, there are good grounds for believing that natural selection is incapable of creating new classes. The “edge of evolution” has not yet been precisely identified, but it appears to lie somewhere near the taxonomic level of the family or super-family.
In the meantime, the science of biochemistry has revealed a host of complex systems within the cell, which can only be described as cellular machines. In the words of molecular biologist Michael Denton: “Although the tiniest bacterial cells are incredibly small, weighing less than 10^(-12) grams, each is in effect a veritable micro-miniaturized factory containing thousands of exquisitely designed pieces of intricate molecular machinery, made up altogether of one hundred thousand million atoms, far more complicated than any machinery built by man and absolutely without parallel in the non-living world” (“Evolution: A Theory in Crisis,” Adler & Adler, 1985, p. 250). The problem of how these cellular machines originated as a result of blind natural processes is more intractable than ever, as Professor Behe has recently demonstrated in his discussion of the bacterial flagellum in The Edge of Evolution. The eye, too, continues to yield surprises, too, as scientists have uncovered regulatory switches that trigger the development of the eye in nearly all kinds of animals – but at the same time, they haven’t a clue how these complex regulatory cascades originated.
Finally, the cell itself appears to be unfathomably complex – a city seems to be the best metaphor we can construct for it at present, but I suspect that no human metaphor will ever do it justice. As Nicholas Talbott has argued in a recent article in The New Atlantis, the scientific quest for a non-lifelike foundation for life is a misbegotten one: “In the study of organisms, ‘It’s life all the way down.'”
Natural selection, then, appears woefully inadequate to account for the complexity we find in living things; and it appears incapable of radically transforming organisms beyond the taxonomic limits of the family. The experimental evidence massively contradicts Darwinism as a scientific theory. Living things appear to have evolved from a common stock; but natural selection is incapable of making living things evolve much at all.
Why is Darwin’s theory still revered in scientific circles?
Yet Darwin’s theory still revered in scientific circles, while Newton’s theory of gravity and Wegener’s theory of continental drift have been cheerfully cast aside by scientists, in favor of better theories. In this respect, Darwin’s theory is strikingly different from the other two theories. Why is this? And what can we do about it?
Stephen Jay Gould, in the essay quoted above, wrote that “The lesson of history holds that theories are overthrown by rival theories.” The problem in this case is that the rival theory (Intelligent Design) is unpalatable to most scientists. Hence the exaggerated reverence for Darwin displayed in academic circles.
At the present time, Intelligent Design proponents have to contend with a wall of scientific prejudice against the notion of life’s having had a Designer, and there remain formidable legal hurdles to Intelligent Design theory even getting a hearing in American high school science classrooms. An alternative strategy, however, might be to neutralize the theory of evolution taught in high school classrooms. How? By “Newtonizing” it.
Newton, it will be recalled, refrained from linking his theory of gravity to any scientific hypothesis as to its cause. As he wrote in his General Scholium of 1713: “I have not yet been able to discover the cause of these properties of gravity from phenomena and I feign no hypotheses… It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies, and of our sea.” (Emphasis mine – VJT.)
Nested hierarchies exist, and they are a pervasive feature of organisms. Their mutual consistency, coupled with their compatibility with the fossil evidence, strongly implies common descent. What nested hierarchies do not imply, however, is Darwinism. If scientists were honest, this is what they would teach in high school classrooms:
“We have not yet been able to discover the causes of the various complex properties of organisms from observed phenomena, and we feign no hypotheses… It is enough that nested hierarchies really do exist, that they are mathematically describable, and that they apply to all of the features of living things, suggesting common descent.”
Now that would be a curriculum change for the better. Will we see it happen? Time will tell. But I think it would definitely be a legal avenue worth pursuing.
What do readers think?