The Fishy Story of Fish History

Logistical Problems with the evolution of fish 

There are two main problems confronting the proposition that fish evolved from some other non-fish kind. Firstly, there is no evidence that fish had any non-fish ancestors.  The Cambrian explosion when interpreted through evolutionary timescales indicates that there were no precursors to sea creatures.  According to Bertha Bell, “The earliest fishes to appear in the fossil record were odd-looking jawless creatures whose bodies were armoured with bony plates. They lived in the oceans during the late Cambrian period, about 510 million years ago,” (Bell 2018: slide 46).  Fossils found in lower strata are microorganisms, without organs or physiology compatible with creatures of the Cambrian period (Wells 2017:28).

Secondly, there is no conceivable pathway for development from a precursor creature to a fish.  Accounts of the evolution of fish vary and conflict.  For example Scientific American states that, “fish evolved from ancestral vertebrates in the sea” (Wilcox 2012), while Bell argues, “Fishes were the first vertebrates to evolve” (Bell 2018: 45).   Randall Harris attempts to detail a possible evolutionary process from a bunch of cells to a fully developed fish, but concedes this line of development entails impossible scenarios, for example the evolution of the heart (Harris 2014: 3156-3172).  Harris attempts to follow the evolutionary path of the development of the main organs and features of a modern fish, and in so doing brings into focus some of the intractable problems it raises.  In what follows I will look at some of the evolutionary scenarios Harris attempts to unpack and identify the ways they undermine the theory.   

Harris begins by describing the development of a tube-like structure, reasoning that this would be one of the fundamental components of the fish’s infrastructure. The evolutionary account focuses on the evolved system, rather than the evolutionary process: “From the fish's mouth, food passes through a short tube called the oesophagus to the stomach, where it is partially broken down”... “Liver, pancreas (near stomach): secrete bile and digestive enzymes,” (Bell 2018: 62, 71).  For this system to arise, Harris hypothesises, “the first proto-fish gathered around a nutrient source and linked its cells to from a tube,” then “continued replication made the tube longer and thicker...the outer layer of cells would have been subjected to the erosive forces of water mutant cell with a stronger surface bond, however, would have resisted the erosive forces better than others and reproduced to develop a strong covering around the tube,” (Harris 3122-28).  “Over time the tube grew in many dimensions...the cells taking in food at the front collected more nutrients while those in the middle became more reliant on storage...some cells would have been robbed of nutrients and become waste.  Eventually a cavity formed that could pass waste cells to the outside.  This process was effectively a filtering mechanism, possibly the first primitive kidney.” (3127-3134). This kidney would be the creature’s first organ.  Harris goes on to speculate about the origin of the others.

In the absence of a coherent evolutionary account Harris outlines the implicit, albeit bizarre, scenario by which internal organs in principle came into existence.  “The tube now has a food source and waste system.  If the rear end closed up, internal pressure would have forced more forks and cavities to develop.  Over time these cavities would each develop special characteristics that fulfil a range of internal functions that we know about today,” such as: spleen, liver, the intestine and stomach, the bladder, the circulation, brain and nervous system, (Harris 2014:  3100-3317).

The evolutionary account does not say how the circulatory system came into existence, but merely states what it does.  “Fishes have closed circulatory systems with a heart that pumps blood around the body in a single loop—from the heart to the gills, from the gills to the rest of the body, and back to the heart,” (Bell 2018: 83). However, Harris finds it impossible to come up with a scenario for the evolution of the heart.  Harris explains that a fish heart has two chambers and pushes blood through the gills where it is oxygenated. “The process of separating oxygen from water, passing it into blood cells and targeting specific organs involves extremely complex biological mechanisms and would have needed to work from the very start of life,” (3165-3172). The heart would need to be present for the cells to develop into a fish, “but at this stage of development the proto-reptile has yet to develop any neurological cells or systems,” (3156-3165).  That is to say, by the evolutionary account the fish has a heart at this stage, but no brain.

Harris explains that for all living bodies, without the brain the body will die.  There would need to be a heart to sustain the brain, although the heart itself needs neurological monitoring. The evolutionary account has it, “Fishes have well-developed nervous systems organized around a brain, which has several parts...The most anterior parts of a fish's brain are the olfactory bulbs, which are involved with the sense of smell, or olfaction They are connected to the two lobes of the cerebrum In most vertebrates, the cerebrum is responsible for all voluntary activities of the body However, in fishes, the cerebrum primarily processes the sense of smell The optic lobes process information from the eyes The cerebellum coordinates body movements The medulla oblongata controls the functioning of many internal organs,”(Bell 2018:90).  Harris envisages a possible scenario: “The most likely option appears to be that firstly a heart self-created and then started its own pumping action.  Then the brain, the circulatory system...and the blood self-created,” (3187).  Harris explains, “The brain and the heart need to co-exist so the creature can live while developing new parts,” (3187).  Harris postulates the heart, brain, circulatory system and blood “self-creating” virtually simultaneously since they all depend on one another and are essential to all the other body parts.  He highlights the inability of gradual evolution to achieve this outcome since the brain and the vascular system need to be up and running to support each other.  A half-developed brain could not maintain a vascular system, and vice versa.

Furthermore, in order to transmit electrical impulses between the brain and the organs there would need to be appropriate channels, eventually becoming the vertebral column. Harris explains, “The vertebral column in a proto-fish would need to develop from calcium excesses into a perfect symmetrical layout that assists in holding muscles in place and helps maintain the overall shape of the organism.  Vertebrae have to form with many identical joints, evenly spaced, moving in unison with muscles,” (3195). Harris lists other developments that would need to occur, such as the spread of nerves to all parts of the body.  He concludes, “All these things had to occur of their own accord without a plan or reason,” (3195).  Harris goes on to detail other features the proto-fish would need to evolve.


Harris gives an indication of just how sophisticated the fish’s brain would need to become. “The proto-brain cells of our proto-fish needed to develop the specialised ability to use chemical ions to transfer messages between themselves and the rest of the body,” (3204).  “The proto-brain would also need to categorise [returning messages] as sight, sounds, tastes, touches, pain, and so forth.  It would need to understand three dimensions, size, shape, colour, movements and textures,” (3212). It would need to evolve awareness and memory, “and to have some form of knowledge of what constitutes a problem and the correct course of action to take to ensure survival,” (3212).  Harris concludes his postulated sequence of events for the development of the proto-brain and vascular system saying, “Science cannot explain how the first proto-brain self-created, cell-by-cell and function-by-function without a pre-existing program from which to operate,” (3220). The evolution of fins likewise proves inexplicable in evolutionary terms.

Fins are especially for fish and for the specific purposes fish require them for.  This would suggest a rational process led to their existence, which is contrary to the purported ‘blind’ process of evolution.   Harris postulates how the fish next acquired its fins.  “Perhaps a group of cells stuck out from the main body of the fish casing it to move only in one direction, possibly around and around in circles.  Perhaps many outcrops formed on the fish’s surface.  Over time some of these may have fallen off, others grown bigger and, purely by chance, finished up in the most appropriate positions to allow the fish the flexibility to manoeuvre....Although fish need specific fins in specific locations, evolutionary mutations are blind and random.  The chance that fish will have fins is no more or less likely than any, or every, other type of living thing having fins, even humans. The obvious dilemma for evolution is that fish are the only creatures with fins because they need them,” (3238).   What Harris is saying here is that evolution can only be accounted for by random developments.  It cannot be teleological, that is, aiming at some final goal.  However, fins are necessary only to fish, and only fish have them unlike, for example, eyes which are necessary to many species. 

Although Dawkins and Alexander and others have argued that a part-developed eye would be useful, Harris maintains that the process by which the fish eye evolved would defy known natural processes.   He elaborates some of the required steps: “the biology of the eye is such that it has to be complete in every part with a fully functioning lens and nerves connected at both ends for it function at all.  As cells replicate randomly, mutants would have to form over dozens of highly complex but different parts of the eye without any effect happening.  They would have to remain in that form without further change until the next million accidental replications caused the next layer to build up. Otherwise any one of the new components could be lost to eternity,” (3269).  Harris is saying that millions upon millions of accidental mutations would need to build up over time and remain in place without any benefit to the fish.  This would be like metal filings from a factory lathe randomly gathering themselves over decades to form a key, and then other filings coming together by chance over centuries to form a matching lock.

The order of complexity for the evolution of eyesight is multiplied by the fact that the account needs to explain paired vision in terms of chance. Added to the difficulty of an evolutionary account of the eye, Harris points out, is the need to account for the evolution of the corresponding second eye of the pair.  He says, “our proto-fish has two [eyes].  Being the first creature with sight it would need to simultaneously develop both eyes at the same time, symmetrically lined up at the front of the skull, complete and functioning with intact optical nerves attached to its proto-brain,” (3269).  He adds, “Scientists...are far from close to matching this brilliant function [eyesight] despite knowing how it worked beforehand.  Yet evolution claims the first eye in history self-created identically twice without plan or purpose,” (3278).  This is like explaining the existence of a pair of glasses by saying a skewer and a glass tumbler fell into a liquidiser and a piece of glass fell precisely into a lens-shaped configuration of the now spectacle shaped skewer.  In the effort to extract the frame, complete with lens, from the liquidiser a window was accidentally broken and a fragment of glass fell into a second hollow in the frame to form an identical and perfect second lens.  

Harris succeeds in showing some of the intractable problems encountered by an evolutionary account of the existence of fish.  These include the need for the heart and brain to evolve rapidly and simultaneously, for vital organs to perform their tasks from the outset, and for body layout and symmetry to be integrated. What Harris shows is that from a practical and logistical perspective the implied process of the evolution of fish from non-fish would entail so much vital work to be completed for life to be sustained that the prospect of it coming about in this way is inconceivable.  This Harris establishes by limiting himself to a consideration of a limited range of the fish’s organs and faculties. Without touching on the matter of reproduction, Harris highlights so many problems for fish evolution as to render the process a non-starter.  


Bell, B. ‘Nonvertebrate Chordates, Fishes and Amphibians’ (Slide Presentation), Pearson Prentice Hall Biology [accessed 04.08.2018]

Harris, R. (2014) Evolution Unravelled:  How Science Disproves Evolution Glenside, South Australia: Starmonics Pty Ltd (references are to the ebook)

Wells, J. (2017) Zombie Science: More Icons of Evolution Seattle: Discovery Institute Press

Wilcox, C. (2012) ‘Evolution: Out of the Sea’ Scientific American [online at] [accessed 11.08.2018]

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