Wall-Climbing Cave Fish: Evolutionary Intermediate?


Scientists recently discovered another bizarre fish.1 This one has a pelvic girdle. Is it the missing link evolutionists have been searching for?

The scientific name of this supposed "evolutionary relic" is Cryptotora thamicola. Those with a Darwinian worldview maintain Cryptotora gives us a hint of the water-to-land transition undergone by early tetrapods (four-limbed vertebrates) some "400 million years ago." One reason for this speculation is because Cryptotora has a unique style of locomotion:

Here we show that the blind cavefish Cryptotora thamicola walks and climbs waterfalls with a salamander-like diagonal-couplets lateral sequence gait and has evolved a robust pelvic girdle that shares morphological features associated with terrestrial vertebrates.2

But does this cavefish, with its questionable "tetrapod-like gait," give insight to the unobserved fish-to-amphibian evolution? The New York Times article wisely adopts a cautious tone, "Dr. Flammang said that the waterfall-climbing cave fish eventually might give scientists hints about how fish originally arrived on land."1 Indeed, this unique creature clearly does not align with fossils morphologically intermediate between fishes and tetrapods:

It is, however, crucial to note that Cryptotora is not an analogous representative of any early tetrapodomorph described to date.2

But where are the fossils that document the rise of this pelvis-possessing fish from an "ordinary" fish? ICR addressed the absence of fossils that would bridge the gap between fish and the alleged first amphibian via a pelvic girdle.3 Evolutionists can only hypothesize:

Standen et al. hypothesized that environmentally induced phenotypic plasticity may facilitate macroevolutionary change; however, our current data does not allow us [to] discriminate between selection for a robust pelvic girdle specifically or for the plastic response to extreme environmental conditions.2

Furthermore, evolutionists state that the digited appendages evolved before the complex pelvic girdle during fin-to-limb evolution, but Cryptotora clearly lacks any digited appendages. Apparently this cave fish doesn't know it's supposed to abide by evolution's rules—it's a fish with fins.

Creation zoologists suggest this waterfall-climbing cave fish is designed to exploit (move in and fill) a distinctive environment, just as Tiktaalik4 seems designed to occupy a pre-Flood wetlands environment. Catfish also have a unique niche, "walking" up close to shore and snagging prey from the land—usually birds.

The bottom line is the fish-to-tetrapod transition has yet to be documented anywhere in the sedimentary rocks:

The transitional path between fin structural elements in fish and limbs in tetrapods remains elusive.5

The question of where tetrapods evolved is even more difficult to answer than that of when.6

Zimmer states in the New York Times article, "Scientists still puzzle over exactly how the transition from sea to land took place."1 Non-darwinists heartily agree, because the transition apparently never took place.

References

  1. Zimmer, C. 2016. Researchers Find Fish That Walks the Way Land Vertebrates Do. New York Times. Posted on nytimes.com March 24, 2016, accessed April 15, 2016. 
  2. Flammang, B. et al. 2016. Tetrapod-like pelvic girdle in walking cavefish. Scientific Reports. 23711 (2016): doi:10.1038/srep23711. 
  3. Sherwin, F. 2013. Paleontology's Pelvic Puzzle. Acts & Facts. 42 (5): 16. 
  4. Sherwin, F. Banner Fossil for Evolution Is Demoted. Creation Science Update. Posted on ICR.org January 27, 2010, accessed April 28, 2016. 
  5. How the genetic blueprints for limbs came from fish. University of Geneva press release, January 21, 2014.. 
  6. Clack, J. 2012. Gaining Ground: The Origin and Evolution of Tetrapods, 2nd edition. Bloomington, IN: Indiana University Press, 128.

Image credit: Copyright © 2016 D. Fenolio/Science Source. Adapted for use in accordance with federal copyright (fair use doctrine) law. Usage by ICR does not imply endorsement of copyright holders.

Article posted on May 5, 2016.

*Mr. Sherwin is Science Writer at the Institute for Creation Research.