The science section of The Testimony has long since ceased to be anything but a liability for our community, with its constant stream of poorly-researched articles. I’ve
repeatedly called out the magazine on this
subject; it hurts our credibility, and gives unbelievers plenty of ammunition
to destroy our credibility. Unfortunately the magazine continues to publish error-riddled articles that peddle the usual long-rebutted special creationist arguments against evolution. This month, The Testimony has published an article on
evolution that resorts to the intellectually dishonest practice of
quote mining.
The article in the November 2013 edition, Genesis and Darwinism by Gary Penn makes innumerable mistakes, beginning with its failure to properly define evolution. Penn makes the mistake of taking a definition from an English language dictionary rather than consult a standard biology text. Incredibly, he takes a definition from the online Oxford Dictionary, and then paraphrases it to arrive at his definition:
A basic definition of evolution is: “the process by which different kinds of living organisms are believed to have developed from earlier forms during the history of the earth.” Put another way, evolution is the belief that simple organisms developed into more complex organisms over many generations.
That is a woefully inadequate
description which fails to differentiate between evolution as fact (common
descent and large scale evolutionary change) and evolution as theory (the
modern synthetic theory of evolution). There is no excuse for Penn to fail to
make that distinction as it has been recognised for over 150 years, as Darwin
himself pointed out on at least two occasions. In 1863, he emphasised that
recognition of common descent was by far the more important principle than the
precise theoretical mechanism behind how descent with modification occurred.
Whether the naturalist believes in the views given by Lamarck, or Geoffroy St.-Hilaire, by the author of the ‘Vestiges,’ by Mr. Wallace and myself, or in any other such view, signifies extremely little in comparison with the admission that species have descended from other species and have not been created immutable; for he who admits this as a great truth has a wide field opened to him for further inquiry.[1]
Eight years later in The Descent
of Man, he was even more explicit in differentiating between common descent,
and natural selection, his proposed theoretical mechanism to explain it:
Some of those who admit the principle of evolution, but reject natural selection, seem to forget, when criticising my book, that I had the above two objects in view; hence if I have erred in giving to natural selection great power, which I am very far from admitting, or in having exaggerated its power, which is in itself probable, I have at least, as I hope, done good service in aiding to overthrow the dogma of separate creations.[2]
Within a few years of the
publication of The Origin of Species, the weight of evidence rapidly persuaded
scholars of the reality of common descent, even if his proposed mechanism of
natural selection fell out of favour by the late 19th century and only made a
comeback in the early 20th with the forging of the modern evolutionary
synthesis. Evolutionary biologist T.R. Gregory points out that the fact of
common descent is simply no longer a matter of discussion as the evidence for
it is overwhelming:
In The Origin of Species, published in 1859, Darwin cited independent lines of evidence such as the biogeographical distribution of species, homology of structure, the occurrence of vestigial organs and atavisms, and the already well established process of extinction as all pointing to a conclusion that species have changed over time and are connected by descent from common ancestors. Through the force of Darwin’s argument and the mass of supporting data he presented, it was not long before the contemporary scientific community came to acknowledge the historical reality of evolutionary descent. As A.W. Bennett summarized the situation in 1870.
The fascinating hypothesis of [descent with modification] has, within the last few years, so completely taken hold of the scientific mind, both in [Great Britain] and in Germany, that almost the whole of our rising men of science may be classed as belonging to this school of thought. Probably since the time of Newton no man has had so great an influence over the development of scientific thought as Mr. Darwin.Over the past 150 years, this initial list has been supplemented by countless observations in paleontology, comparative anatomy, developmental biology, molecular biology, and (most recently) comparative genomics, and through direct observations of evolutionary change in both natural and experimental populations. Each of thousands of peer-reviewed articles published every year in scientific journals provides further confirmation (though, as Futuyma notes, “no biologist today would think of publishing a paper on ‘new evidence for evolution’ ... it simply hasn’t been an issue in scientific circles for more than a century”). Conversely, no reliable observation has ever been found to contradict the general notion of common descent. It should come as no surprise, then, that the scientific community at large has accepted evolutionary descent as a historical reality since Darwin’s time and considers it among the most reliably established and fundamentally important facts in all of science.[3]
Penn never informs
his readers of these facts, but simply paraphrases a dictionary definition of
evolution and fails to make the crucial difference between common descent and
large-scale evolutionary change and natural selection. Instead, he retreats to fundamentalism and fideism:
"As believers in the supremacy of the written Word of God, what should be our attitude to the theory of evolution?”
Penn would do well to take the
advice of W.D. Jardine, one of the earliest Christadelphian writers who in 1864
wrote:
The inconsistency spoken of between nature and scripture, arises not from antagonism, but from the misinterpretations of both. It is man’s interpretation of the one set against man’s interpretations of the other. It is not nature versus scripture, but false science against true theology, or false theology against scientific fact. Some scientific men, we believe, view the Scriptures through the distorted medium of “confessions of faith” and doubt them, and theologians view science and call it false, because it does not take to their turn-pike road.[4]
A hyper-literal reading of the creation narratives is flatly refuted by modern science, so Penn would be well advised to take Jardine's advice and read the creation narratives in the light of the overwhelming evidence of an ancient, evolving creation.
It is fascinating, if depressing to see just how advanced the early generation of Christadelphians were in their attitude towards science. C.C. Walker, the second editor of the flagship magazine The Christadelphian recognised that the fossil record was not consistent with either a recent creation or the ‘Gap Theory’:
“If we suppose a sudden and absolute break some 6,000 years ago, or before, resulting in the destruction of all life, and that the creation account of Genesis describes a new creation following, we ought to find some evidence of the break, and we cannot well account for the apparently close relationship that obtains between extinct and existing forms. There are forms becoming extinct in our own day from slow and natural causes. May it not have been so in pre-Adamic times? The professors tell us for instance that some of these ancient birds, whose strides we can see for ourselves from their footprints were from four to six feet long, were like gigantic ostriches.” [5]
Even more amazing is brother Walker’s willingness to
accept that if the scientific evidence was compelling, then interpretations of
Genesis would need to be changed to bring them into harmony with science (emphasis mine):
‘Supposing that it were ever established that they were the actual progenitors of our smaller forms (“There were giants in the earth in those days” might apply to birds and beasts), would the credibility of the Mosaic narrative suffer? Not at all, in our estimation. We should indeed have to revise somewhat our interpretation of the brief cosmogony of Gen. 1.; but should not waver as concerning its divinity.”[6]
This is as close to accepting evolution as our community has ever come, and even today, this article is light years ahead of anything that is published today in terms of honestly engaging with the scientific evidence.
Such intellectual honesty and humility is completely absent from the science section of The Testimony, where a mindless fideism, uncritical adoption of YEC ideas from the evangelical Christian world and outright science denialism pepper the magazine. Penn's article is about as far removed from the spirit of Walker's article as is possible to imagine.
Penn is frustratingly close to recognising that laypeople are simply not in a position to dismiss a scientific discipline if they are ignorant of the basics:
For the nonscientist, this may feel like a real challenge. The material produced in its defence may seem overwhelming—volumes upon volumes of charts, figures, articles, peer-reviewed research papers, boxes with arrows, and so forth.
It is hard not to get angry with
this wilful ignorance. The intellectually honest approach would be to recognise
that he is not an expert, is unable to assess the primary literature, and
therefore should assume that when > 99% of professional biologists and
palaeontologists examine the evidence and conclude that common descent is the
best explanation for the data from palaeontology, comparative genomics,
developmental biology, biogeography and other disciplines, they may actually be
telling the truth. The amount of quality material on evolution in the print and
electronic media aimed at the educated layperson is overwhelming. There is
simply no excuse for ignorance.
Penn’s next step is to resort to
misquoting Darwin:
Natural selection may account for stronger gazelles, but does it explain how the gazelle developed in the first place? Does it explain how individual organs—the ear, the eye, the digestive system—evolved? Darwin himself acknowledged this challenge in his most famous book, On the Origin of the Species: “To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree.”
This is a shamefully dishonest
misquotation of Darwin, who would often pose a rhetorical question, then answer
it. Special creationists often quote the first part of Darwin, but fail to continue the quote, thus
completely changing the meaning of the quote in context. Here is the quote in
context:
To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree. Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered real.
Had Penn bothered to continue the
quotation, he would have shown his readers that Darwin did not regard the evolution of the
eye as being impossible. This is disgraceful. A high school student who handed
in a paper that quoted references in such a shabby way would be failed, yet
Penn and the The Testimony science editor David Burges, under whose watch this article was allowed in print think that this is
justified. It is not. Intellectual dishonesty is never justified.
Darwin continued to show that a range of
plausible intermediates existed then stated:
If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case.
Either Penn has blindly quoted a
special creationist source without bothering to properly check the reference,
which is incompetent scholarship, or he has deliberately misquoted Darwin, which is
intellectually dishonest behaviour.
Penn, had he bothered to do more than misquote Darwin and actually research the subject, would have discovered that the evolution of the eye no longer poses any fundamental problem for biology. Nilsson and Pelger in an article published nearly 20 years ago[7] modelled eye evolution and found that the number of generations required for the evolution of a spherical eye from a light sensitive patch was amazingly short, on the scale of a few hundred thousand years. As the authors pointed out, “in this context, the eye was never a real threat to Darwin’s theory of evolution”[8]
Representation of Nilsson and Pelger’s complete model for eye evolution
Source: http://musingsofscience.wordpress.com/tag/evolution-of-the-eye/
It gets worse. Penn trots out the
long-rebutted special creationist argument that no transitional fossils exist,
then gives us another Darwin
quote mine:
Where is the fossil record of simple life forms in transition to more complex forms? Again, Darwin comments: “Why then is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such finely graduated organic chain; and this, perhaps, is the most obvious and gravest objection which can be urged against my theory.”
This is the full quote in
context:
In the sixth chapter I enumerated the chief objections which might be justly urged against the views maintained in this volume. Most of them have now been discussed. One, namely the distinctness of specific forms, and their not being blended together by innumerable transitional links, is a very obvious difficulty. I assigned reasons why such links do not commonly occur at the present day, under the circumstances apparently most favourable for their presence, namely on an extensive and continuous area with graduated physical conditions. I endeavoured to show, that the life of each species depends in a more important manner on the presence of other already defined organic forms, than on climate; and, therefore, that the really governing conditions of life do not graduate away quite insensibly like heat or moisture. I endeavoured, also, to show that intermediate varieties, from existing in lesser numbers than the forms which they connect, will generally be beaten out and exterminated during the course of further modification and improvement. The main cause, however, of innumerable intermediate links not now occurring everywhere throughout nature depends on the very process of natural selection, through which new varieties continually take the places of and exterminate their parent-forms. But just in proportion as this process of extermination has acted on an enormous scale, so must the number of intermediate varieties, which have formerly existed on the earth, be truly enormous. Why then is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such finely graduated organic chain; and this, perhaps, is the most obvious and gravest objection which can be urged against my theory. The explanation lies, as I believe, in the extreme imperfection of the geological record.
Penn once again has failed to
continue the quotation, which shows once again Darwin’s style of posing a question, then
answering it. In fact, the quote comes from the first paragraph of chapter 9,
“On the Imperfections of the Geological Record” where Darwin addresses the question of the
geological record, and concludes:
For my part, following out Lyell's metaphor, I look at the natural geological record, as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a short chapter has been preserved; and of each page, only here and there a few lines. Each word of the slowly-changing language, in which the history is supposed to be written, being more or less different in the interrupted succession of chapters, may represent the apparently abruptly changed forms of life, entombed in our consecutive, but widely separated formations. On this view, the difficulties above discussed are greatly diminished, or even disappear. (Emphasis mine)
Transitional fossils, contrary to Penn’s assertion, are plentiful. Part of the problem is that special
creationists such as Penn peddle the discredited idea of ‘missing links’ which
reflects a false view of evolution as a ladder (the scala naturae) rather than
abranching tree:
The concept of a "missing link" is an "archaic expression"...tracing back to the Great Chain of Being, a view of the physical and metaphysical world as an unbroken chain. It was later temporalized by the evolutionary thought of the eighteenth and nineteenth century to the idea of evolution as a progressive climb up a ladder... These views of evolution create the false expectation that there should be fossil evidence showing "a complete chain of life from simple to complex"...Creationists rely on such views to support their arguments against macroevolution, in particular by pointing out the "conspicuous" absence of "large numbers of intermediate fossil organisms"...using what is still unknown to question whether evolution has occurred.[9]
Even then, as Louise Mead, author of the above quote notes, there
is still a creationist expectation that 'intermediate' forms must be found, a
view which is unrealistic as such forms would have been outcompeted by
"newly adapting forms." It also shows that creationists
(unsurprisingly) are ignorant of what evolutionary biologists actually look for
when reconstructing evolutionary relationships. Organisms are now classified on
the basis of the presence of ancestral or derived traits:
Rather than trying to find the actual fossil corresponding to the "missing link" between lobe-fins and tetrapods, paleontologists instead look for fossils with characters or features important for an adaptive transition from life in an aquatic environment to life on land and that are shared as the result of common ancestry…
Thinking of evolution as a progression from simple to complex, or ladder-like, furthers the idea that evolution is lineal and that it should be possible to reconstruct a direct line of ancestors. However, the evolution of life, instead of resembling a ladder, is more similar to a branching bush. Darwin's (1859) contribution to phylogenetic analysis indeed was to introduce the concept of a branching tree of life, with organisms related through common ancestry.[10]
One of the best examples of
transitional fossils is that of the Devonian fish Tiktaalik roseae [11] which is a near-perfect transitional between a fish and a tetrapod:
a, Left lateral view; b, dorsal view with enlargement of scales; and c, ventral view with enlargement of anterior ribs. See Fig. 3 for labelled drawing of skull in dorsal view. Abbreviations: an, anocleithrum; bb, basibranchial; co, coracoid; clav, clavicle; clth, cleithrum; cbr, ceratobranchial; ent, entopterygoid; hu, humerus; lep, lepidotrichia; mand, mandible; nar, naris; or, orbit; psp, parasphenoid; ra, radius; suc, supracleithrum; ul, ulna; uln, ulnare. Scale bar equals 5 cm. - Daeschler E.B., Shubin N.H, Jenkins F. “A Devonian tetrapod-like fish and the evolution of the tetrapod body plan.” Nature. 2006; 440(7085):757-63
a, Dorsal view of body with scales removed depicting orientation of ribs as preserved in NUFV 108. b, Lateral view. The ribs are shown in dorsoventral orientation. Number of ribs is estimated from the incompletely preserved series in NUFV 108. - Daeschler E.B., Shubin N.H, Jenkins F. “A Devonian tetrapod-like fish and the evolution of the tetrapod body plan.” Nature. 2006; 440(7085):757-63
Arguably
the most important feature of Tiktaalik is that it has a wrist, which takes its
upper fin even closer to being classed as a limb:
The array of joints in the distal fin is functionally similar to the multiple transverse joints that characterise the carpal, metacarpophalangeal and interphalangeal joints of the tetrapod manus. The distal endoskeleton of Tiktaalik invites direct comparisons to the wrists and digits of limbed vertebrates. The intermedium and ulnare of Tiktaalik have homologues to eponymous wrist bones of tetrapods with which they share similar positions and articular relations. In both Tiktaalik and early tetrapods, the ulnare is block-shaped and articulates with multiple radials or digits, whereas the intermedium is a simple rod. The formation of a mobile transverse joint at the distal margin of these bones in Tiktaalik presages the establishment of a functional proximal carpal joint.”
“As in the digits and phalanges in a tetrapod limb, the inter-radial joints distal to this primordial wrist are more or less transversely aligned and capable of flexion and extension. The occurrence of multiple distally facing radial rows that are capable of flexion and extension is a likely antecedent condition to the dactyly of early tetrapods. The transformation of fins to limbs, then, probably entailed the elaboration and proliferation of structures, joints and functions already present in the fins of fish such as Tiktaalik.”[12]
a, Stereo pair of left pectoral fin of NUFV 108 in dorsal view showing disparity in size and position of anterior (alp) and posterior (plp) unjointed lepidotrichia and the relative position of dermal girdle elements. b, Right pectoral fin of NUFV 110 in anterior view showing preservation of anterior lepidotrichia (alp), clavicle (cl), scales (sc) and endochondral bones in articulation (H, humerus; U, ulna; u, ulnare; r, radials). The anterior lepidotrichia terminate at the elbow, thus allowing a full range of flexion at that joint. c, Right pectoral fin of NUFV 110 in ventral view showing positions of coracoid (co) and endochondral and dermal fin elements. an, anocleithrum; cb, ceratobranchial; clth, cleithrum; int, intermedium; ri, rib; suc, supracleithrum. - Shubin NH, Daeschler EB, Jenkins FA. The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb. Nature. 2006;440(7085):764-71.
To summarise the above comments from the research paper:
- The bones in the pectoral fin of Tiktaalik perform similar functions to those in the tetrapod upper limb
- Furthermore, these bones are homologous to those in the tetrapod limb
- Although Tiktaalik is a fish by definition (it has scales and the presence of rays means it has fins instead of limbs), structurally and functionally, it is clearly transitional between fish and tetrapod to the point that it blurs the transition and fully warrants the name ‘fishapod’
a, b, Anterolateral view. c, d, Ventral view. a, c, Resting posture with the fin partially flexed at the antebrachium. In this position the radius is slightly more flexed than the ulna. b, d, Resistant contact with a firm substrate entails flexion at proximal joints and extension at distal ones. The shoulder joint is flexed by ventral muscles, including the trans-coracoid muscle. The elbow is flexed (d, arrow 1), with slight pronation of the radius (d, arrow 2) and rotation of the ulna (d, arrow 3). The transverse joints distal to the ulnare and intermedium are extended (d, arrows 4). - Shubin NH, Daeschler EB, Jenkins FA. The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb. Nature. 2006;440(7085):764-71.
As the authors note:
The pectoral skeleton of Tiktaalik is transitional between fish fins and tetrapod limbs. Comparison of the fin with those of related fish reveals that the manus is not a de novo novelty of tetrapods; rather, it was assembled in fishes over evolutionary time to meet the diverse challenges of life in the marshes of Devonian aquatic ecosystems.[13]
Tiktaalik is only one of many
transitional fossils which confirm the reality of large-scale evolutionary
change. That Penn never once tells his readers these facts alone is enough to
destroy the credibility of his article.
Conclusion
As with the quote on the
evolution of the eye, Penn has either copied the quotation from another special
creationist source, or deliberately misquoted Darwin for apologetic purposes. To do it
twice is simply appalling. It also stands as an indictment of the abysmal quality of material published in the science section which is under David Burges’ editorship. I am embarrassed and angry that such an intellectually dishonest,
poorly researched article could ever be published in a Christadelphian magazine, particularly considering what we used to publish over 100 years ago. One can hope that The
Testimony apologises for allowing such a fundamentally dishonest
article to see print and misleading its readers on this subject.
References
[1] Darwin CR. Origin of species [Letter]. Athenaeum 9
May: 617; 1863.
[2] Darwin
C. The descent of man, and selection in relation to sex. London: John Murray; 1871.
[3] Gregory T.R. “Evolution as Fact, Theory and Path” Evo
Edu Outreach (2008) 1:46-52
[4] Jardine W.D “The Bible as a Law of Life and
Immortality” The Ambassador of the Coming Age (1864) 1:93
[5] Walker CC “Genesis” The Christadelphian
(1910): 47:501
[6] ibid
[7] Nillson
D, Pelger S “A Pessimistic Estimate of the Time Required for an Eye to Evolve” Proc. R. Soc. Lond. B (1994) 256:53-58
[8] Ibid, p 58
[9] Mead LS
"Transforming our Thinking About Transitional Forms" Evo Edu
Outreach (2009) 2:310–314
[10] ibid p
311
[11] Daeschler
E.B., Shubin N.H, Jenkins F. “A Devonian tetrapod-like fish and the evolution
of the tetrapod body plan.” Nature. 2006; 440(7085):757-63
[12] Shubin
NH, Daeschler EB, Jenkins FA. The pectoral fin of Tiktaalik roseae and the
origin of the tetrapod limb. Nature. 2006;440(7085):764-71.
[13] Shubin,
Daeschler, Jenkins. op cit, p 769
