What Is Biofluorescence, and Did It Evolve?

Baffled by biofluorescence
diversity, scientists claim it
evolved separately 100+ times

 

Something’s Fishy:
Fumbling Evolutionists Tell a Tall Tale about Biofluorescent Fish

by Sarah Buckland-Reynolds, PhD

From the San Juan Islands in Washington, to the Luminous Lagoon in Jamaica, biofluorescent marine fish have mesmerized millions of curious onlookers for generations. Their awe-inspiring, ethereal glow serves far more than a mere aesthetic purpose. In fact, there is growing evidence that it plays a vital role in their ecosystem: facilitating communication, providing camouflage, and even luring prey – functions all woven into their biological design. Yet, despite the remarkable aesthetic and functional sophistication of these organisms, prevailing evolutionary models continue to assert that such complexity emerged through entirely undirected random processes—remarkably, suggesting that biofluorescent traits independently evolved over a whopping 100 times.

In two studies published in Nature Communications and PLOS One Journals in May/June 2025, PhD Candidate, Emily Carr and colleagues defaulted to an evolutionary approach in explaining research that led to their conclusion that teleost fishes’ beautiful biofluorescence underwent a 112-million-year evolutionary timeline of transformation, with 100 instances of evolutionary changes. Just how did they come to this conclusion? Not from any observational evidence, or transitional fossils, rather, using probabilistic phylogenetic models built on the faulty assumptions of a predefined evolutionary sequence. But does the supposed statistical justification they rely on truly support the idea that such intricate design could arise through mere happenstance?

Swishing A Circular Tale

Phylogenetic models are mathematical frameworks used to infer evolutionary relationships among species based on genetic, morphological, or other biological traits. These models hypothesize the ancestral history of organisms and attempt to reconstruct how traits may have changed over time. These models rest on numerous assumptions, including the gradual accumulation of traits over vast timescales—frequently bridging gaps in the fossil or genetic record not with direct evidence, but with statistical inference.

In the case of Carr and colleagues, they based their model on a previous “time-calibrated phylogeny” of marine fishes developed by Daniel Rabosky and published in Nature in 2018. As typical in evolutionary literature, the equivocation of speciation as steps in the macro-evolutionary process was pervasive in Rabosky’s work.  Carr and colleagues based their statistical mapping of biofluorescent fish evolution on a presumed evolutionary sequence.

Yet, if the analysis begins with an assumed phylogeny to order the species, can the outcome truly be considered independent support for that very sequence? This represents a classic case of circular reasoning—conclusions that are effectively embedded within the assumptions, rather than emerging from independent discovery. As with many evolutionary publications before and since, researchers often construct models assuming the accuracy of unexamined evolutionary premises, reinforcing the prevailing evolutionary framework, rather than subjecting it to critical empirical testing.

Pigmentation Perfection: Too Complicated to be Coincidence

As Carr and colleagues imply, biofluorescence is not a simple function, rather, this process forms part of an elaborate network of other biological processes governing pigmentation. Fluorescence in fish is enabled by complex molecular structures, often involving specialized proteins that manipulate light in remarkable ways. Increasingly, even evolutionary authors conducting research on biofluorescent creatures have highlighted the fine-tuned functionality of fluorescence. For instance, Whitcher et al (2023)’s study on amphibians admitted to biofluorescence being ‘tuned’ with environmental-specific signals.

Biofluorescent fish contain pigment cells capable of absorbing and re-emitting specific wavelengths of light, yet this process demands intricate coordination between cellular structures. Fluorescent compounds must be properly positioned in the body, synchronized with environmental conditions, and maintained through precise biological regulation. While evolutionists interpret this as ‘adaptation’, there is no evolutionary explanation for the origin of such regulations. Therefore, a more reasonable explanation of this observation of alignment to its surroundings would be through pre-programmed genetics/epigenetics.

A partially developed fluorescence system would confer no clear ecological or functional advantage; only a fully functional and integrated system yields observable benefits such as communication, camouflage, or predation. If any one of these key components were absent or not fully developed, biofluorescence would fail to operate efficiently, rendering any proposed evolutionary “intermediate stages” useless. Such intricacy in pigmentation strongly points to intentional design rather than accidental mutation as the best explanation for its origin.

More Guesswork with Gills: Four Fundamental Evolutionary Flounders

Despite their reliance on evolutionary frameworks, in a twist of irony, the researchers’ conclusions inadvertently highlighted several flaws in Darwinian evolutionary theory:

• Undermining Uniformitarian Theory: The authors concluded that fish species in coral reef habitats

…evolve biofluorescence at about 10 times the rate of non-reef species, with an increase in the number of fluorescent species following the Cretaceous-Paleogene (K-Pg) extinction about 66 million years ago, when all of the non-avian dinosaurs died off.

The claim that biofluorescence evolved 10 times faster in reef fish after the K-Pg extinction suggests a dramatic shift in evolutionary pace. Ironically, however, evolutionary theory assumes gradual trait development. If biofluorescence was evolving slowly before the extinction then suddenly accelerated afterward, wouldn’t that undermine gradualist assumptions? This shows that even evolutionists are increasingly abandoning uniformitarian theory!

• Unexplained Diversity and Unpredictable Progression: Carr and colleagues’ work also brought to attention the broad variance of the likelihoods of various shades in biofluorescence. Rather than displaying a predictable progression in line with biological theory, biofluorescence emerges in erratic patterns across teleost lineages. Some groups maintain stable red fluorescence, others green, while a minority shift between both or lose fluorescence altogether. These inconsistencies should not exist if trait inheritance were a gradual, predictive process like evolutionary theory predicts.
• Devolution in Action: One of the study’s most baffling revelations is that some supposedly more advanced lineages lost fluorescence altogether. This is change in the wrong direction. If biofluorescence is advantageous, why did some fish hit the genetic “undo” button? Carr and colleagues’ findings highlight that the presumed evolutionary nodes do not align into a straightforward, branching tree, but instead reveal a far more complex and nuanced pattern of relationships. These “trait reversals” (instances where fluorescence disappears in certain lineages despite its earlier presence) raises fundamental challenges to the evolutionary framework. Again, could it be that fluorescence is not a trait that developed by slow random processes over time, but is rather an intrinsic feature granted to specific organisms by design?
• The Lucky Fish Presented Forms a Statistical Anomaly: The claim that biofluorescence evolved over 100 times independently in teleost fish is a statistical anomaly. If the same trait repeatedly emerged in different lineages, it may again suggest that biofluorescence was already embedded in the genetic makeup of these fish and was simply expressed differently over time. The idea that a complex trait like biofluorescence evolved separately so many times strongly challenges the assumed randomness of evolutionary theory.

Recognizing Purpose, Attributing Evolution

Despite building on the foundations of evolutionary theory, Carr and colleagues’ research uncovers wondrous examples of diversity and clearly points to purpose.

For example, in their PLOS One article, they exclaim:

Our results reveal far more diversity in both fluorescent emission wavelengths (colors) and in the distribution of fluorescent molecules across the body than had previously been reported in the literature.

However, this discovery poses yet another problem for evolution (as increasing diversity always does) –  as it points to complexity and multiplies the number of supposed evolutionary jumps that are required to achieve it.

Their discovery also builds upon what they already admit having known about the multiple and complex functionalities of biofluorescence. Referencing previous literature in their Nature Communications article, Carr and colleagues admit that:

… carnivorous pitcher plants (Nepenthaceae and Sarraceniaceae) fluoresce along the lip of the pitcher, which attracts insect prey… Sexual dimorphism in green biofluorescence and ultraviolet (UV) reflectance is thought to aid in the mating rituals of jumping spiders (Salticidae)… In marine fishes…biofluorescence has been implicated in camouflage, communication, species identification, mating, and prey attraction. The Pacific spiny lumpsucker (Eumicrotremus orbis) exhibits sexually dichromatic fluorescent emission colors from the body that may enhance mate identification, whereas fluorescence of the pelvic disc in both males and females is thought to be utilized for signaling.

Not only did their research build further hurdles for evolutionary theory, but their findings also highlight just how finely-tuned these biofluorescent signals are. Quoting from their article:

These potential visual functions of biofluorescence all require that fluorescent emissions lie within the spectral sensitivity of relevant signal-receivers: conspecifics, predators, and/or prey.

So, do they mean that somehow, undirected processes worked on tuning the spectral properties of the biofluorescent proteins to align with the intended receivers of these visual signals?

Magnificent Medical Machines

In further striking irony, while attributing the development of biofluorescence to undirected evolutionary processes, Carr and colleagues nonetheless, in their conclusion, acknowledged its remarkable functional precision—even highlighting potential biomedical applications as the next stage of their research. In a commentary posted by the American Museum of Natural History, it was stated that:

The researchers also note that the numerous wavelengths of fluorescent emissions found in this study could have implications for identifying novel fluorescent molecules, which are routinely used in biomedical applications, including fluorescence-guided disease diagnosis and therapy.

This functionality has been documented in several other peer-reviewed literature, including Biosensors, Annals of Biomedical Engineering, and Seminars in Colon and Rectal Surgery, with increasing applications in a variety of medical procedures.

Designed to Dazzle

Reflecting on Carr and colleagues’ attempt to reconstruct biofluorescence through evolutionary modeling raises significant doubts about the validity of gradual mutation-based development. The inconsistent trait distribution, loss of fluorescence in some lineages, and the sheer complexity of pigmentation mechanisms indicate that fluorescence is not a product of unguided natural selection. Instead, it appears to be a pre-existing design, intentionally embedded within biological systems.

Even without recanting their allegiance to evolutionary assumptions, Carr and colleagues’ research gives us another glimpse of the wonders of God’s creation. Everywhere we look, from the skies to the seas, points to evidence that further undermines evolutionary randomness and upholds purposeful creation.

As scientists continue trying to explain nature’s marvels without God, all creation itself continues to proclaim the glory of its Creator. May we do the same. As the beautiful and insightful words in Job 12:7-10 so eloquently describe:

But ask the beasts, and they will teach you; the birds of the heavens, and they will tell you; or speak to the earth, and it will teach you; and the fish of the sea will declare to you. Who among all these does not know that the hand of the Lord has done this?

Amen.

---

Dr. Sarah Buckland-Reynolds is a Christian, Jamaican, Environmental Science researcher, and journal associate editor. She holds the degree of Doctor of Philosophy in Geography from the University of the West Indies (UWI), Mona with high commendation, and a postgraduate specialization in Geomatics at the Universidad del Valle, Cali, Colombia. The quality of her research activity in Environmental Science has been recognized by various awards including the 2024 Editor’s Award from the American Meteorological Society for her reviewing service in the Weather, Climate and Society Journal, the 2023 L’Oreal/UNESCO Women in Science Caribbean Award, the 2023 ICETEX International Experts Exchange Award for study in Colombia. and with her PhD research in drought management also being shortlisted in the top 10 globally for the 2023 Allianz Climate Risk Award by Munich Re Insurance, Germany. Motivated by her faith in God and zeal to positively influence society, Dr. Buckland-Reynolds is also the founder and Principal Director of Chosen to G.L.O.W. Ministries, a Jamaican charitable organization which seeks to amplify the Christian voice in the public sphere and equip more youths to know how to defend their faith.