Gordon Rattray Taylor on the fish-to-amphibian transition

I have been having fun today revisiting my old quotes (and scanning new ones) for my Quotes Book.

Here are three by Gordon Rattray Taylor from his book, "The Great Evolution Mystery" (1983). First on the fish to amphibian transition, which despite claims like "Darwin Would Have Loved It" (i.e. Tiktaalik roseae), by TIME magazine, the transition, as Taylor (a committed fully naturalistic evolutionist) pointed out, was as un-Darwinian as one could imagine:

"When we survey the evolutionary story, from the first multicellular creatures up to man we soon get the feeling that from time to time there was a dramatic change of plan - and indeed of lifestyle - that is quite inconsistent with the slow accumulation of imperceptible changes upon which Darwin based his theory. Evolutionists call such discontinuities 'saltations' (that is, jumps). The study of evolution in this large sense is sometimes called megaevolution, in contrast with the micro-evolution of species; the term macro-evolution is also used but is ambiguous, since some workers use it for evolution only slightly above the species level. ... The most obvious and striking of these major steps was the step from sea to land, a step taken some 360 million years ago. Suddenly, four-legged air-breathing creatures appeared - quite unlike the scaly, limbless, water-breathing fishes which had been the most prolific creatures up to this time. ... So why did the fishes invade the land? No one knows. The real obstacles to such a move were the massive structural changes needed to make life on land worthwhile. To begin with, the fish would need legs simply in order to relieve the pressure of its body on the ground, which would compress the lungs. Equally importantly, the land animal needs a strong pelvic girdle. The fins of fishes are attached only to bony plates beneath the skin and could not support the weight of the body until a link had been provided to transmit their support to the spine. There were problems with the front suspension too, for in fishes the forward fins are firmly linked to the skull. Turned into legs, the animal would have to move its head from side to side with each step, so a new system of suspension had to be provided. Finally, since the weight of the body was no longer taken by the water, the spine itself needed strengthening. We are all so used to the idea of bone that it is hard for us to realise what a milestone the creation of bone was. Without bone, or something very like it, many terrestrial creatures could not support themselves against the drag of gravity. ... And so on to the next step, because land animals must also protect their body from drying out, by swapping scales for an impervious skin. Actually, the skin of some modern amphibians is quite sophisticated: it admits water when the creature returns to that element, the increased permeability being under hormonal control. We do not know if anything of the kind occurred in primitive amphibians. Land animals also need to protect their eyes from drying by a flow of tears and need an eyelid to protect it from dust particles. Similarly the nose must be protected by a supply of mucus. The land animal must also change its sense organs. It no longer needs the curious organ which runs along its side called a lateral line, and this is converted, by an amazing series of steps which I shall shortly describe, into the ear. The eye, too, changes, since the refractive index of air is different from that of water and no doubt there are modifications in the sense of smell ... And then, of course, there is the problem of the legs themselves. Before ever the fish reached the land the structure of its fins began to change. Instead of rays, a series of bones corresponding to the tibia, radius and ulna of the arm appeared. Digits, tarsals and metatarsals evolved (so it is now generally conceded) as wholly new structures, though the point - unwelcome to Darwinians - was hotly contested in the 1930s. The fish which decided to remain fish very sensibly, converted their lungs into swim-bladders with which they could regulate the depth at which they swam. Though we have this clue in the bone-structure of the crossopterygian fin there are no intermediate forms between finned and limbed creatures in the fossil collections of the world. Once again the critical evidence for gradual evolution is missing. The earliest definitely four-footed creatures known were found in strata some 370 million years old in Greenland, which at that time was not icy but had a mild climate. Known as Ichthyostegids, they possessed a five-toed foot but retained the fishy tail and the lateral line of their fishy ancestors. Their skulls, however, were already typically amphibian and their jaws were equipped with teeth. About three feet long, they probably lived in shallow waters and impaled small fish on their sharp teeth. They are the nearest we can get to a 'missing link' in this context." ... All that need concern us is the larger question of whether such an impressive array of coordinated changes could have taken place by chance, and have done so without leaving in the fossil record a single intermediate form to prove the point. As Darwin complained: 'Where are the infinitely numerous transitional links' that would illustrate the action of natural selection? Not here, at any rate." (Taylor G.R., "The Great Evolution Mystery," Harper & Row: New York NY, 1983, pp.55-57, 59-61. My emphasis)

Just note again those "massive structural changes needed to make life on land worthwhile": 1) "the fish would need legs"; 2) "a strong pelvic girdle" with; 3) "a link provided to transmit their support to the spine"; 4) "a new system of suspension had to be provided"; 5) "the spine itself needed strengthening" (leaving aside the original "creation of bone" - see `tagline' below - which "required not one but a whole burst of mutations, all integrated to a single end "); 6) "protect their body from drying out, by swapping scales for an impervious skin"; 7) "protect their eyes from drying by a flow of tears"; 8) "need an eyelid to protect it from dust particles"; 9) "the nose must be protected by a supply of mucus"; 10) "change its sense organs. the lateral line is converted, by an amazing series of steps into the ear" (see further below).

As for 6) "legs," "Before ever the fish reached the land the structure of its fins began to change. Instead of rays, a series of bones corresponding to the tibia, radius and ulna of the arm appeared. Digits, tarsals and metatarsals evolved (so it is now generally conceded) as wholly new structures (and note there were two pair, i.e. four-arms and legs), rather than just one pair - arms, which would be all that was needed to flop between pools, not that it needed even that-just stiff fins would have done).

And as Taylor rightly noted by his: 'Where are the infinitely numerous transitional links' that would illustrate the action of natural selection? Not here, at any rate," this did (and does) not support Darwin's theory of the natural selection of random micromutations!

As Taylor observes (and I wholeheartedly agree), this "progressive series of changes" to just one part, the conversion of the fish lateral line into the land animal's inner ear "look more like the refinement of a plan than the result of a series of happy accidents" (my emphasis):

"With all this, of course, went improvements in the brain, most notably the power to compare the times at which signals from one source reach each ear, thus providing a method of estimating the direction in which the source lies. ... In contrast with the case of the eye, where undifferentiated cells were specialised into the required forms, here existing structures have been profoundly modified and even shifted to another position in a progressive series of changes which certainly look more like the refinement of a plan than the result of a series of happy accidents. But the insoluble problem is how and why did a balance organ become an organ of hearing? As van Bergeijk pointedly asks: 'What prompts the fish to begin developing a sensory apparatus that will respond to a stimulus about the very existence of which the fish knows nothing?' ... After describing the last part of this process, the adaptation of the bones linking the jaw to the skull into a chain of ossicles linking the eardrum to the inner ear, Ernst Mayr sweepingly remarks: 'Not all the steps in this process are yet entirely apparent, but I think little doubt is left as to the principle involved.' If by 'principle' one means merely progressive remodelling, the statement is a truism. But if 'principle' means that chance selection brought about these elaborate changes, then there must be very great doubt indeed. Like de Beer, Mayr does not seem to appreciate the elementary point that demonstrating the occurrence of a sequence of events does not explain why they happened. But what kind of mutations could bring about the major changes I have described? Could cause a tube to roll up into a helix? Could cause other tubes to form semi-circular canals accurately set at right angles to each other. Could grade sensory hairs according to length? Could cause the convenient deposit of a crystal in the one place it will register gravity? Even more amazingly, some fishes do not trouble to secrete a crystal but incorporate a bit of sand or stone. What kind of mutation could achieve this - when and only when a natural crystal is not formed? The purpose is fulfilled, the means are unimportant. It just doesn't make sense." (Taylor, ibid., 1983, pp.105-106)

I assume that this in fact was "the refinement of a plan" and (as previously posted here and here) this will form part of my `Construction Project' Design Argument (see here; here and here), when I eventually write my book, "The Design Argument."

Stephen E. Jones, BSc (Biol).
"Problems of Evolution"

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We are all so used to the idea of bone that it is hard for us to realise what a milestone the creation of bone was. Without bone, or something very like it, many terrestrial creatures could not support themselves against the drag of gravity. ... Bone has a precise, indeed an unique, structure, being composed of mineral and living matter interspersed. The strength of bone comes from the mineral component: crystals of hydroxyapatite; the adaptability from the living collagen. The two are arranged in specific patterns, with spaces reserved for living bone-making cells and for blood vessels. You may be one of those who think of bone as inert, stony, almost eternal. In fact it is highly mobile, almost fluid on the evolutionary scale. Bone-building cells add to it here, bone-destroying cells erode it there, until it is sculptured into a different form, even in the span of a single lifetime. On the evolutionary scale, of course, much bigger changes are possible. If one of the larger bones is sliced in half, it is seen to contain a spongework of criss-crossing sheets, the trabeculae, which align themselves in precisely the best way to absorb the stresses to which that particular bone, in that individual, is being subjected. Like the network of girders which support a bridge or a structure like the Eiffel Tower, this gives strength for a minimum of weight. In addition the major bones contain a cavity, lined with a special sheath, which generates the blood cells needed by the blood. Human blood cells have a life of only 120 days, and you and I rely on our marrow providing a stream of replacements. Another membrane covers the exterior. (It is from the internal and external sheaths that the bone-making cells come.) Then there is the mystery of joints with their capsule of cartilage and their remarkable lubricant, the synovial fluid. It is obvious that the creation of bone required not one but a whole burst of mutations, all integrated to a single end - an incredible thing to happen by chance even if nothing else had been going on." (Taylor, ibid, 1983, p.57. My emphasis)