The theory of evolution suggests that land animals evolved from fish, with fins gradually transforming into limbs, allowing them to move from water to land.1,2,3 The fossil record, however, provides no evidence for such a dramatic evolutionary leap.
In 2012, Jennifer Clack, a leading vertebrate paleontologist, stated, ‘The question of where tetrapods evolved is even harder to answer than the question of when.’1 Additionally, a 2018 scientific article noted, ‘The transition from fish to tetrapod is one of the fundamental problems of evolutionary biology.’4
This supposed transition from water to land would have required the development of numerous new skeletal structures, muscles, nervous systems, sensory organs, internal organs, and respiratory systems.1,2,3,4 Moreover, these adaptations would have needed to facilitate the shift from gill breathing to lung breathing.
Lobe-finned fish
Lobe-finned fish (Sarcopterygii) are a group of scaly fish whose fins are structurally different from those of other scaly fish, as each fin is supported by a fleshy, bony stalk resembling a lobe. Evolutionary theorists have interpreted this feature as a possible precursor to limbs, considering it as evidence for the evolution of arms, hands, legs, and feet.1,2,3,4 In reality, however, Sarcopterygii are simply a distinct group of fish with their own unique characteristics.
Lobe-finned fish make a sudden appearance at the beginning of Devonian deposits, alongside numerous other fish species. Modern examples of these fish include coelacanthiformes and lungfish. Once believed to be extinct, coelacanthiformes are now known to still exist, residing in the deep ocean, far from any evolutionary trajectory that would lead to land-dwelling creatures.
Evolutionists consider Panderichthys the primary candidate for a transitional link between fish and amphibians. Fossils of this species are found in the late Devonian period. In contrast to other lobe-finned fish, Panderichthys had a more flattened head and lacked dorsal fins, giving it a more primitive, tetrapod-like appearance. However, its rear fins, where hind limbs would have evolved, were quite small. For this reason, it is often regarded as one of the earliest fish on the evolutionary path to land-dwelling life.
It is important to note that evolutionists commonly refer to the animals mentioned in this article as tetrapods, even though they did not possess the true ability to walk.
Tiktaalik
Next in the evolutionary progression is Tiktaalik, regarded as one of the most crucial transitional links between fish and land-dwelling tetrapods.1,2,3 It shared many features with its supposed evolutionary precursor, Panderichthys. However, Tiktaalik had a slight gap between its head and shoulder region, which allowed for greater head movement; its forelimbs had more joints, offering its fins a greater range of motion; and its pelvic girdle was larger and more developed.
As such, evolutionists suggest that Tiktaalik may have been able to haul itself onto land, similar to modern mudskippers. In reality, though, its fins were still essentially fish fins and lacked the strength to support its weight on land. Even Clack conceded, ‘Tiktaalik’s fin pairs still retain fin rays: the loss of fin rays is part of how limbs are differentiated from fins’.5 Tiktaalik was therefore simply a unique species of fish, incapable of living or walking on land.
Acanthostega
Acanthostega, found in late Devonian deposits, follows Tiktaalik on the evolutionary tree.1,2,3,5 While it displayed many fish-like characteristics, evolutionists regard it as an early tetrapod due to its limbs bearing digits.5 Acanthostega also had an enlarged pelvic girdle, although it differed structurally from Tiktaalik’s. Despite this, its pelvic girdle was still relatively small compared to land-dwelling tetrapods, lacking bony connections to the spine and relying instead on soft tissue attachments. Furthermore, it possessed a tail fin supported by long bony rays and gills, much like those of fish.5 Its shoulders and forelimbs were clearly reminiscent of fish anatomy.
As noted earlier, Acanthostega had protrusions with digits—eight on its forelimbs and six on its hind limbs. Land tetrapods, however, typically have five digits. Moreover, the eight digits on Acanthostega’s forelimbs were webbed, indicating they functioned as paddle-like fins. Its limbs also lacked joints, meaning the forelimbs could not bend forward at the elbow, preventing it from assuming a weight-bearing position and making land locomotion impossible.
It is evident that Acanthostega’s limbs and digits were suited for swimming, and perhaps for grasping aquatic plants. Even Clack acknowledged that it was an aquatic animal that never left the water.5 Thus, we encounter the same scenario once again—the supposed transitional link is revealed to be a distinctive type of fish that eventually went extinct.
Ichthyostega
The final purported transitional link in the evolutionary sequence is Ichthyostega. This creature also displayed characteristics that suggest it was well adapted to aquatic life, including fully functional gills and a tail fin running along its back, supported by fin rays—similar to the dorsal fin of a fish.1,2,3,5
Although Ichthyostega’s limbs were more developed than those of its supposed evolutionary predecessors, they were not suited for terrestrial movement. The humerus and femur lacked the necessary rotation, as shown by computer simulations of Ichthyostega’s bones, meaning the animal could not stand or place its hands or feet flat on the ground. As a result, it was unable to push off from the ground or move its limbs in an alternating manner, as land-dwelling tetrapods do.6
Ichthyostega also displayed other features that are problematic for evolutionary theory, including a spinal structure that differed from evolutionary assumptions7 and seven digits on its hind limbs. Clack referred to it as a ‘problematic kind’ and noted, ‘Ichthyostega, far from being a typical Devonian tetrapod, is highly specialized in its own right.’5
As a result, this animal also fails to serve as a transitional form between aquatic and terrestrial animals.
The transitional link remains missing
After Ichthyostega, the fossil record offers no further candidates for transitional forms. Clack observes, ‘The post-Devonian tetrapod fossil record is notably sparse for approximately 30 million years following the Devonian-Carboniferous boundary (Mississippian epoch).’5 This view is echoed by vertebrate paleontologist Michael Benton, who suggests, somewhat optimistically, that ‘fully terrestrial tetrapods may not have emerged until 25 million years later in the Carboniferous.’ This, however, remains speculative.
Tetrapod evolution without confirmation
Not only is there a lack of evidence in the form of transitional fossils between water and land, but there is also an issue with the dating of these specimens. All the fossils mentioned above are confined to a relatively brief period in the middle and late Devonian (385–365 million years ago).1,2,3,5 A span of twenty million years seems insufficient for such significant evolutionary changes to have occurred.
Moreover, recent discoveries have further complicated the situation. In 2010, well-preserved tracks of terrestrial tetrapods were found on an ancient tidal flat in Poland, with an estimated age of 397 million years.8 These fossilized footprints indicate the presence of two-meter-long terrestrial tetrapods with thick limbs at that time.
Since these tracks were created before the animals discussed in this article existed, the entire narrative of tetrapod evolution is called into question. The authors of the 2010 study concluded: ‘[The tracks] necessitate a fundamental reassessment of the timing, ecology, and environmental conditions of the fish-to-tetrapod transition, as well as the completeness of the body fossil record.’9 Reflecting on this study, Clack remarked in The Guardian: ‘It completely undermines the entire story, so to speak.’9
Conclusion
The evolutionary account of the transition from aquatic to terrestrial life lacks convincing support. The series of fossilized fish-like creatures seems to add complexity to the issue rather than providing clarity. Meanwhile, the discovery of fully terrestrial tetrapod tracks in rocks older than those containing the supposed transitional forms directly challenges the evolutionary model.
By the way, we recommend reading the articles:
- Antimatter – A Challenge for the Big Bang Theory
- Homo Erectus – Ape or Human?
- The Formation of the Solar System: What Do We Really Know?
- Does the Bible Imply that the Earth is Flat?
- Earth – the Only Planet with Fire
Footnotes
- Clack, J., Gaining Ground: The Origin and Evolution of Tetrapods, Bloomington, IN: Indiana University Press, 2012.
- Benton, M. J., ‘Early Tetrapods and Amphibians’, in Vertebrate Paleontology, West Sussex, UK: John Wiley & Sons Ltd, 2015.
- Dial, K. P., N. Shubin, and E. L. Brainerd, Great Transformations in Vertebrate Evolution, Chicago, IL: University of Chicago Press, 2015.
- Wood, T. W. P. and T. Nakamura, ‘Problems in Fish-to-Tetrapod Transition: Genetic Expeditions Into Old Specimens’, Frontiers in Cell and Developmental Biology, 6, 70, 2018.
- Clack, J. A., ‘The Fish-Tetrapod Transition: New Fossils and Interpretations’, Evolution: Education and Outreach, 2, 213-223, 2009.
- Pierce, S. E., J. A. Clack, and J. R. Hutchinson, ‘Three-dimensional Limb Joint Mobility in the Early Tetrapod Ichthyostega’, Nature, 486, 523-526, 2012.
- Pierce, S. E. et al., ‘Vertebral Architecture in the Earliest Stem Tetrapods’, Nature, 494, 226-229, 2013.
- Niedźwiedzki, G. et al., ‘Tetrapod Trackways from the Early Middle Devonian Period of Poland’, Nature, 463 (7227), 43-48, 2010.
- McVeigh, K., ‘Footprints Show Tetrapods Walked on Land 18m Years Earlier than Thought’, The Guardian, posted on guardian.co.uk, 6 January 2010, accessed 21 January 2010.
Based on: J. P. Tomkins, The fossils still say ‘no’: the fins-to-feet transition, Acts & Facts, Institute for Creation Research, March 2021, pp. 10-13.
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