The ID Update

The phenomenon of convergence has been recognised in external morphology (e.g. the streamlined shape of sharks and porpoises), structural detail (e.g. the camera-like construction of the vertebrate eye and the octopus eye), and in many other functional aspects of organisms (e.g. the echolocation systems used by bats and whales). In textbooks and popular science writing, convergence is often explained in a Darwinian way, invoking the amazing powers of natural selection. However, far from being a curiosity that pops up from time to time, convergence appears to be a pervasive feature of the living world. Championing this perspective is Professor Simon Conway Morris, an evolutionary palaeontologist from Cambridge University, who is actively contributing to debate and constructing an online database of specific examples.

Similarities between different types of animal and plant are examples of convergence (source here)

Triggering this blog is an opinion piece in EMBO Reports, where Conway Morris draws attention to remarkable examples of convergence drawn from the field of molecular biology. Whether we consider systems for sight or sound or smell, the molecules that are crucial for converting stimuli into electrical signals have some fundamental similarities. To enable vision, for example, opsins are employed throughout the animal kingdom.

"[N]ot only do [opsins] belong to the vast family of G-protein-coupled receptors (GPCRs), but it is no accident that, in ears and noses, related transmembrane proteins with the canonical seven helices are also poised to transduce noise and smells into electrical signals and ultimately awareness."

But the main point drawn by Conway Morris relates to the olfactory systems found in insects:

"One component, concentrated in the coeloconic sensilla, is tasked with detecting molecules such as alcohol and ammonia. Here, the machinery depends on the ionotropic glutamate receptors. This appears to be a classic case of co-option because not only are these receptors ancient, they also show fascinating links to synaptic receptors. However, the bulk of the olfactory capacity looks to a series of transmembrane proteins. At first glance, complete with their seven helices spanning the sensory membrane, they look reassuringly like the ever-reliable GPCRs. Except they aren't! Blink twice and then notice that these proteins are back to front so that the amino-terminal is cytoplasmic and the carboxy-terminal extracellular. This is completely opposite to the GPCRs, but surely it represents a trivial difference? On the contrary. Lurking in the insect 'nose' is a ligand-gated cation channel that at first sight looks practically identical to a GPCR but is completely unrelated."

Insects, then, display a "near perfect mimic" in this element of their olfactory systems. For Conway Morris, the interesting corollary is that replaying the tape of life does not lead to something radically different, for the end results are "very much the same". This is the first of the messages to emerge from convergence.

"With respect to the receptor protein, frankly who cares if it is a GPCR or a ligand-gated ion channel protein? They are completely unrelated, but the far more remarkable fact is that, in terms of transduction, the system evidently has no alternative. The molecule must be a seven-helix transmembrane protein; this is the molecule of choice. Evolution meets design: Darwin and Plato embrace."

Setting Darwin alongside Plato is unusual in contemporary science literature. The comment "Evolution meets design" is similarly noteworthy. What is intended here? Darwinian evolution is normally presented as a full explanation of apparent design, so most Darwinists will scratch their heads and question whether Conway Morris really understands Darwinism. An example of this follows later.

Nevertheless, the implication of Darwin embracing Plato is that these two have been apart for too long and the route to achieve reconciliation is via convergence. Darwinists have developed a perspective on evolutionary transformation that looks like a random walk. There is no direction, no goal, no over-riding architecture. The tensions between this approach and the perspective developed by Conway Morris are well expressed in his opening paragraph:

"How best to describe evolution? A drunkard's walk; a shambling billion-year spree punctuated with prat-falls, accompanied by a Beckettian mumbling? Or a sleek greyhound rippling with suppressed energy, racing along the narrow highways of the Darwinian landscape? "Mumble and shuffle" would be the answer of most biologists, but perhaps next time we open our Darwin we should also turn up The Ride of the Valkyries."

So what relevance is Plato for evolutionary biology? Plato's philosophy invoked a transcendent intelligence, and rationality was associated with mind rather than matter. Although chance and necessity have their place in the world, they are part of a bigger picture goverened by the ultimate wisdom. Plato spoke of ideal Forms which represent the essence of what we see around us. The ideal Forms represent reality; the observed objects are transient derivatives. To a critic who stated: "I see particular horses, but not horseness", Plato replied: "That is because you have eyes but no intelligence." This, then, is Plato's contribution to evolutionary biology: convergence points to an essence beyond the particulars. There is a bigger picture that can easily be missed by those who are unaccustomed to contemplating transcendence or who are ideologically opposed to the concept.

It follows that there is no substance to Gould's famous claim that replaying the tape of life would lead to a different set of organic forms. For Conway Morris, replaying the tape of life brings out the same essences - the same ideal Forms. The ubiquity of convergence guarantees it. Even if life were on other planets, it would follow the same patterns:

"Rest assured that on Threga IX - that charming little planet just to the left of Arcturus - eyes will flicker and noses will swivel beneath an alien sun. We can save ourselves all the fuss of an extremely expensive extraterrestrial excursion. In those alien eyes and noses, we can be quite certain that a seven-helix transmembrane protein will be busy telling its owner that the sunset is red and dinner is almost ready."

These issues are highly significant for two reasons. The first concerns the entrenched way Darwinians advance the concepts of randomness, accidents and improbability. At the time of writing, the New Scientist has just published an article on a gene duplication in the hominid lineage that is said to be crucial for understanding human intelligence. The accompanying editorial warms to the idea that humanity's existence is the result of accidental gene duplications. As the excerpt below shows, there is no hint here of Darwin meeting Plato. Instead, this is an example of Darwin slamming the door in Plato's face and insisting that our humanity is all in our genes.

"The more we learn about our evolutionary journey from ape to human, the more astonishing it seems. Around 3.5 million years ago, a gene involved in brain development duplicated itself in one of our ancestors. Around a million years later it did it again. The duplicate genes now play a crucial role in the design of our big, powerful brains. The double duplication joins a handful of other mutations - notably in FOXP2, also known as the "language gene" - that appear to have endowed us with uniquely human traits. It is no exaggeration to say they are the genes that make us human. On one level that is not hugely surprising. The differences between humans and chimps are obviously encoded in DNA, most likely in genes that determine brain architecture. But on another it brings home the sheer improbability of our existence. The essence of humanity largely boils down to a bunch of random mutations, every one of them happening by chance." (Source: We are the improbable ape)

The second reason for saying the issues are significant is because they have educational implications. How are teachers to handle big questions that are actively being discussed in the scientific community? These includes ultimate questions about meaning and purpose, how to understand design in the cosmos, the significance of mankind, the basis of morality and ethics, our experience of consciousness and free agency, and a host of related issues. All of these are receiving attention within scientific disciplines. Focus for a moment on the nature of humanity. Are we improbable accidents of history? Is consciousness explained (in principle) by genetics. It is not difficult to find affirmative responses to these questions coming from scientists. However, any scientists who answers with a "No!" is faced with the charge that they are religiously motivated and that their religious views have no place in the classroom. This has actually happened to Conway Morris. In 2009, he wrote a popular piece in The Guardian, saying things like:

"How to explain mind? Darwin fumbled it. Could he trust his thoughts any more than those of a dog? [. . .] After all, being a product of evolution gives no warrant at all that what we perceive as rationality, and indeed one that science and mathematics employ with almost dizzying success, has as its basis anything more than sheer whimsy. If, however, the universe is actually the product of a rational Mind and evolution is simply the search engine that in leading to sentience and consciousness allows us to discover the fundamental architecture of the universe - a point many mathematicians intuitively sense when they speak of the unreasonable effectiveness of mathematics - then things not only start to make much better sense, but they are also much more interesting. Farewell bleak nihilism; the cold assurances that all is meaningless."

This received several vigorous responses from scientists committed to naturalism (i.e. nature is all there is). One of these was Professor Jerry Coyne, who wrote a blog with the title: Simon Conway Morris becomes a creationist.

"Contra Conway Morris, there are many people who feel that consciousness is "material" in the sense that it arises from purely material causes in a material object: the brain. Understanding how and why consciousness evolved are hard problems, but to throw one's hands up in despair and say, "God made it" is a ludicrous solution. Give biologists another century of work on the brain, for goodness sake! [. . .] Conway Morris is straying from the scientific path here, but he simply can't help himself. He is a committed Christian, and has to find some way to show that the evolution of humans was inevitable."

It is not my purpose here to analyse these comments, but rather to show their relevance to education. At present, we have Coyne's view regarded by legislators and policy-makers as "science" and Conway Morris' view regarded as "religion". The truth is that both Coyne and Conway Morris have developed positions that can be defended as science, and both bring a religious worldview to their science (Coyne's is atheism, Conway Morris' is Christianity). The real problem is that atheistic scientists have gained too much influence, because they have secularised science and turned it into an instrument for promoting their naturalistic philosophy. This leaves them wide open to confirmation bias - all evidences confirm their naturalistic worldview. Education should not be a battle-ground for worldviews. Let the evidences be taught and teachers should be free to help their students examine all hypotheses with intellectual merit that address these evidences. This means a change of direction for many countries, certainly in the US and certainly in the UK. For more from Conway Morris, a short video clip is here. He argues that the world around us shows abundant signs of being structured, and invites us to consider whether we can identify worldviews that are congruent with these evidences.

Molecules of choice?
Simon Conway Morris
EMBO reports, 13, 281 (28 February 2012) | doi:10.1038/embor.2012.21

[First paragraph is quoted above]

Richard Owen is best known for naming the Dinosauria and for opposing Darwin's "On the origin of species". For the former, he is (usually) celebrated, as the name is in common usage around the world. For the latter, he is reviled as a bigot and his stance allowed subsequent generations of evolutionists to tar him as an obscurantist (although conveniently overlooking his scientific arguments). Owen's statue used to have pride of place in London's Natural History Museum (he oversaw the transfer of the natural history collections to the new South Kensington museum in 1881 and he was knighted in 1884). However, in the lead up to the bicentennial celebrations for Charles Darwin, Owen was moved and a marble statue of Darwin was put in his place. Notwithstanding this treatment, the man does not deserve to be shrouded in the mists of history. His achievements were immense, not least of which was his role in the construction of the Natural History Museum. Owen's expertise was in comparative anatomy applied to living and fossil animals, and his status is that of the best known 19th Century naturalist. Today, few know of his contribution to science by the way he approached the numerous contemporary reports of sea-monsters.

The sea serpent spotted by the crew of HMS Daedalus in 1848 (source here)

From the 1830s, Owen kept a special scrapbook containing letters and newspaper reports of sea-serpents and sea-monsters. He was at pains to point out that he did not have an axe to grind on the authenticity of the claims. He wrote to The Times saying: "I am far from insensible to the pleasure of the discovery of a new and rare animal." We should note that sea monsters were regularly spotted by mariners, that newspapers were keen to run stories on reported sightings, and that these stories captured the interest of readers.

Owen's first public comment came in 1848. The crew of HMS Daedalus was near the Cape of Good Hope when they spotted a serpent-like creature pass their ship. It was 30-40 feet long, had a mouthful of jagged teeth, a mane like a horse and it moved through the water at 15 miles per hour. Several officers witnessed the beast and when the warship arrived back in England, the captain supplied The Times with an account and they went to press on 9th October. Owen's response appeared two days later and pointed out that eye-witness accounts without physical evidence need to be treated cautiously. Without a body or body parts, the possibility of misidentification must be considered very real. The public was fascinated by the story and even the Prince Consort became curious. When Owen suggested to him that the sighting was of a large sea lion or seal, the prince described him as a "sea-serpent killer".

The following year, the Duke of Northumberland took possession of the remains of a monster. Owen identified the specimen as a Ribbon Fish.

"Building upon his growing reputation as a deflater of sea monsters, the magazine Punch ran a satirical poem which read in part, 'who killed the sea-serpent? "I", said Professor Owen'" (page 66).

Sightings continued and Owen continued to dismiss the claims that sea-monsters had been discovered. Believers considered the quality of the observers to be definitive; Owen stood by his argument that the failure to find any bones or bodies was more than an absence of evidence - it was evidence of absence. To give greater credibility to the witnesses, those who supported the veracity of sea monsters took recourse to magistrates and lawyers.

"It had become common practice with sea-serpent sightings to hurriedly collect written eyewitness reports of the events preferably before a local magistrate, lawyer or other official government representative. This was thought an acceptable way of proving the veracity of a creature's existence. Reputable witnesses backed up by the imprimatur of law could not possibly be challenged." (page 67).

As might be anticipated, Owen objected to this practice. For him, it was essential for the eye-witness accounts to be supported by physical evidence. His experience told him that eye-witnesses could be wrong. There is a link here with his museum work. Natural history is a discipline based on evidence, and museums are the places to archive evidence of interest to scholars, to educators and the public. Owen was committed to evidence-based science and he found nothing of substance in the "rival expertise of jurisprudence".

It is something of a paradox to find Owen presented here as championing evidence-based science as the antidote for speculation, whereas his critique of Darwinism is usually portrayed as Owen in speculative mode in the face of evidence-based science! No doubt there is a resolution of this paradox that vindicates Owen from inconsistency, but first we shall consider more closely one aspect of the sea-serpent controversy noted above. It is curious to find that magistrates and lawyers were approached to add their authority to eye-witness accounts of sea-serpents.

Today, we might think this a foolish practice because we know instinctively that the skills of magistrates and lawyers are unsuited to underwriting the authenticity of witnesses of sea-monsters. Yet something similar has happened in recent years when US courts have been asked to make judgments about creationism and intelligent design (ID) in science education. At stake is not just state influence over what teachers can and cannot bring before their students, but also the status of the scientific claims of creationism and ID. In particular, the Kitzmiller vs Dover case in 2005 is widely considered to have inflicted a mortal blow to the credibility of ID. The courts are being used by organisations and individuals with a secularising agenda to gain legal authority for their stance and thereby enhance their credibility. Richard Owen would not have been impressed. He would have stressed the importance of evidence-based scholarship. Scientists are supposed to be good at weighing evidences and testing hypotheses. This is where the emphasis should be placed - in education as well as in the laboratory. (for more, go here).

It is this focus on evidence-based science that explains Owen's critique of Darwinism. Despite the claim to have collected a vast array of evidence to support his theory, Darwin was regarded by many of his peers as strong on hypothesis but light on evidence. To treat any critic coming with this perspective as religiously motivated and anti-scientific is to indulge in rhetoric, not scientific discourse. Owen deserved better. There is nothing paradoxical about his cautious approach to sightings of sea-serpents and his critique of Darwin - he was consistently arguing for evidence-based science. Since rhetoric confirmed by legal judgments has become the norm in the US, the recent ruling by Tennessee State to protect teachers who introduce their students to critiques of Darwinism is justified and is to be welcomed.

Richard Owen and the sea-serpent
Brian Regal
Endeavour, Volume 36, Issue 2, June 2012, Pages 65-68 | http://dx.doi.org/10.1016/j.endeavour.2011.12.001

Abstract: The well known naturalist, Richard Owen, had a career long engagement with monstrous creatures. In the 1830s he famously christened large fossil reptiles, Dinosauria. He investigated fossil marine reptiles as well as the giant moa. He also looked into the sea-serpents and sea monsters then drawing wide public attention. He actively collected letters and analyzed correspondence on the topic, consulted with the admiralty on reports of Royal Navy encounters and sightings, and commented in the public press. He concluded that such reports were based upon misidentifications of whales and other large marine mammals, and not run-ins with mythological creatures. His work on the sea-serpent shows that rather than discount the idea out of hand, a number of high profile naturalists were intrigued by monsters and attempted to understand what they were. His work is key to understanding the skepticism over monsters held by modern mainstream science. This skepticism opened the field to later amateur investigators.

See also:

Tyler, D. Remembering Richard Owen as a "non-evolutionary biologist" (ARN Literature Blog, 8 February 2008).

Tyler, D. Evolution, Museums and Society (ARN Literature Blog, 15 November 2008).

Visitors to the Grand Canyon, and especially those who hike to Plateau Point at the end of Bright Angel Trail, will see a major change in rock type when looking into the inner canyon. The steep walls reveal metamorphosed basement rocks, but resting on these are the horizontally-bedded fresher looking Tapeats Sandstones. The linear boundary between them is known as the "Great Unconformity". There are many other unconformities to be found in the Grand Canyon, but this one is by far the most dramatic. It can be traced as far as the eye can see - and beyond. It is found on most continents:

"The Great Unconformity is well exposed in the Grand Canyon, but this geomorphic surface, which records the erosion and weathering of continental crust followed by sediment accumulation, can be traced across Laurentia and globally, including Gondwana, Baltica, Avalonia and Siberia, making it the most widely recognized and distinctive stratigraphic surface in the rock record."

The trail to Plateau Point on the Tapeats Sandstone (above the Great Unconformity) is in the foreground. A cross-section through the rocks, showing the Great Unconformity, can be seen on the other side of the inner gorge. (Source here)

Not only is the unconformity visually striking, but also it occurs at a special horizon in the rock record: above it are fossils of hard-bodied animals - the unconformity marks their first appearance all over the world. So, this feature is much more than a lithological discontinuity: it is also a faunal discontinuity known affectionately as the "Cambrian Explosion". This distinctive feature of the fossil record has engaged the minds of geologists since it was first recognised. The debate has been whether the "explosion" of life forms was an abrupt punctuation of Earth history, or whether the Great Unconformity hides an inferred record of gradual transformation. Geologists in the 19th Century were unduly influenced by James Hutton and Charles Lyell who set out a view of Earth history that involved endless cycles ("we find no vestige of a beginning, - no prospect of an end"). However, as Gould has admirably explained, geological time is more accurately represented by an arrow, the view that was advanced by some of Lyell's contemporaries.

"Lyell and the catastrophists were locked in a fascinating debate of substance about the way of our world, not a wrangle about methodological aspects of uniformity. Their struggle pitted a directional view of history as a vector leading toward cooler climates and more complex life, and fueled by occasional catastrophes, against Lyell's vision of a world in constant motion, but always the same in substance and state, changing bit by bit in a stately dance toward nowhere. This real debate, so lost at our peril in the success of Lyell's rhetoric, was the grandest battle ever fought between the visions of time's arrow and time's cycle." (page 132)

In a recent paper, two geologists have suggested that the processes involved in forming the Great Unconformity provided a trigger for the Cambrian Explosion.

"The magnitude of the unconformity is without rival in the rock record," Gaines says. "When we pieced that together, we realized that its formation must have had profound implications for ocean chemistry at the time when complex life was just proliferating." "We're proposing a triggering mechanism for the Cambrian explosion," says Peters. "Our hypothesis is that biomineralization evolved as a biogeochemical response to an increased influx of continental weathering products during the last stages in the formation of the Great Unconformity." Peters and Gaines looked at data from more than 20,000 rock samples from across North America and found multiple clues, such as unusual mineral deposits with distinct geochemistry, that point to a link between the physical, chemical, and biological effects." (Source here)

The research has examined sediments in North America overlying the Great Unconformity. These are known collectively as the Sauk sequence. The impact of erosion to produce these rocks on seawater chemistry has been assessed comprehensively. The researchers have consider all the major ionic products of weathering and different depositional environments. Carbonate sedimentation is distinctive:

"The signal of enhanced continental crustal weathering is perhaps most conspicuously expressed by precipitation of carbonate sediments, which reached a Phanerozoic peak in shelf burial flux during the Sauk transgression. In Laurentia, the large quantity of Cambrian-Early Ordovician carbonates is known as the 'Great American Bank'. Precipitation of carbonates is an important sink for alkalinity that is derived from chemical weathering." [. . .] "[Their] results are consistent with a recent model of the Cambrian carbon cycle, which demonstrated that unusually large absolute rates of carbon throughput are required to explain global carbon isotopic excursions."

Alongside the carbonate data are analyses of deposits of glauconite, a potassium-, silica-, and iron-rich mineral that is rarely formed today. These findings confirm the same narrative of extensive continental weathering and have led to the proposal of a "trigger" for the Cambrian Explosion.

"The influx of ions to the oceans also likely posed a challenge to the organisms living there. "Your body has to keep a balance of these ions in order to function properly," Peters explains. "If you have too much of one you have to get rid of it, and one way to get rid of it is to make a mineral."
The fossil record shows that the three major biominerals -- calcium phosphate, now found in bones and teeth; calcium carbonate, in invertebrate shells; and silicon dioxide, in radiolarians -- appeared more or less simultaneously around this time and in a diverse array of distantly related organisms."

Some cautionary words are now worth making. The authors have demonstrated a convincing association of changing seawater chemistry and the first appearance of a great diversity of hard-bodied animals. It is reasonable to propose connections between these observational data. The word "trigger" can be used to describe this association. However, the researchers are proposing more than this. They are claiming that the changing environment drove adaptive change in organisms such that they constructed biominerals: bones and teeth, shells and tests. This additional proposal is unsupported by evidence. Whilst we know that organisms today can extract ions from seawater and make minerals, we do not know that organisms lacking the internal systems to make minerals can adapt to changing environments and somehow develop the necessary internal systems. This is not supported by empirical work today, and any talk of it happening in the past is no more than story-telling. This approach brings the same problems as some other proposed "triggers": the higher levels of oxygenation of seawater and the evolution of eyes.

The "adaption to biomineralization" hypothesis can be tested using the data known to us. By studying the way organisms adapt to environmental change, we can assess the potential for the evolution of systems to build hard body parts. The evidence we have points to extinction rather than adaptive change: natural selection can tweak existing parameters affecting morphology and physiology, but biomineralization requires complex specified information - something that natural selection has not been able to provide. Furthermore, we know something of the life forms living before the Cambrian Explosion, and palaeontologists have found it very difficult to show any direct links between these organisms and the Cambrian animals. In 2007, Adolf Seilacher wrote: "The notion that the majority of Ediacaran fossils do not represent stem groups to modern metazoan phyla is now increasingly accepted." (source here). The Ediacaran fauna is still an enigma. A more viable hypothesis for the proposed "trigger" is that changing seawater chemistry was the reason for most of the Ediacaran species becoming extinct.

In a situation like this, where a convincing correlation has been documented but causation is in great need of critical discussion, there is a strong case for multiple working hypotheses. This is needed to remind researchers and students that proposed causation mechanisms are tentative, if not speculative. Alternatives to that suggested in this paper are urgently required. This blog has advanced an alternative perspective on understanding faunal and floral changes found in the fossil record: the concept of ecological succession constrained by environmental factors. This theme has been discussed here in the context of the Cambrian Explosion, and has appeared in numerous other blogs addressing fossilised animals and plants. The research paper discussed above developed the arguments previously advanced. The implication of pursuing the ecology hypothesis is that the fossil record is not so much a record of evolutionary transformation, but a record of colonisation of Earth environments by the diversity of living things.

Formation of the 'Great Unconformity' as a trigger for the Cambrian explosion
Shanan E. Peters & Robert R. Gaines
Nature, 484, 363-366 (19 April 2012) | doi:10.1038/nature10969

The transition between the Proterozoic and Phanerozoic eons, beginning 542 million years (Myr) ago, is distinguished by the diversification of multicellular animals and by their acquisition of mineralized skeletons during the Cambrian period. Considerable progress has been made in documenting and more precisely correlating biotic patterns in the Neoproterozoic-Cambrian fossil record with geochemical and physical environmental perturbations, but the mechanisms responsible for those perturbations remain uncertain. Here we use new stratigraphic and geochemical data to show that early Palaeozoic marine sediments deposited approximately 540-480 Myr ago record both an expansion in the area of shallow epicontinental seas and anomalous patterns of chemical sedimentation that are indicative of increased oceanic alkalinity and enhanced chemical weathering of continental crust. These geochemical conditions were caused by a protracted period of widespread continental denudation during the Neoproterozoic followed by extensive physical reworking of soil, regolith and basement rock during the first continental-scale marine transgression of the Phanerozoic. The resultant globally occurring stratigraphic surface, which in most regions separates continental crystalline basement rock from much younger Cambrian shallow marine sedimentary deposits, is known as the Great Unconformity. Although Darwin and others have interpreted this widespread hiatus in sedimentation on the continents as a failure of the geologic record, this palaeogeomorphic surface represents a unique physical environmental boundary condition that affected seawater chemistry during a time of profound expansion of shallow marine habitats. Thus, the formation of the Great Unconformity may have been an environmental trigger for the evolution of biomineralization and the 'Cambrian explosion' of ecologic and taxonomic diversity following the Neoproterozoic emergence of animals.

See also:

Evidence for a Geologic Trigger of the Cambrian Explosion, ScienceDaily (18 April 2012)

Luskin, C., Does Lots of Sediment in the Ocean Solve the "Mystery" of the Cambrian Explosion? (Evolution News & Views, 27 April 2012)

Tyler, D. Mapping the appearances of Cambrian animals, (ARN Literature blog, 23 December 2010).

This story by Ashley Powers of the LA Times is a fair summary of the story and trial involving David Coppedge and JPL.

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