Refuting Creationism - Observed Evolution Over 125 Years!

Skull and skin from a vole, collected in 1898 in Chicago.

Authors Stephanie Smith and Anderson Feijó examining chipmunk specimens in the Field Museum’s collections.

Chicago’s rodents are evolving to handle city living - Field Museum

The knee-jerk response from any creationist worth his or her salt, when shown evidence of observed instances of evolution, is to demand a redefinition of the term *evolution*—away from its scientific meaning of a change in allele frequency in a population over time, and towards the creationist’s caricature: a species instantaneously transforming into an entirely unrelated taxon. This is, of course, something evolutionary biologists have never claimed, and which—if it ever occurred—would actually refute the Theory of Evolution.

This is the all-too-familiar, disingenuous tactic of setting the bar impossibly high for one’s opponent, while keeping it at ground level for one’s own evidence-free superstition.

So, for those creationists more interested in finding workarounds to ease the cognitive dissonance between what they would like the facts to be and what science actually shows, than learning the truth about the world around us, the news that researchers at Chicago’s Field Museum have demonstrated evolutionary change in the city’s rodent populations over the last 125 years will likely present little difficulty. They can always chant, “But it’s still a chipmunk/vole/etc., so not evolution!”

However, for those with the intellectual integrity and humility to base their opinions on observable evidence, rather than dismissing any evidence that doesn't conform to their preconceived alternative reality, this finding is a compelling vindication of a basic principle of the Theory of Evolution: that species change over time in response to environmental pressures.

The researchers have recently published their findings in the journal Integrative & Comparative Biology.

Refuting Creationism - The Cambrian 'Explosion' Just Blew Up In Creationists' Faces

Cambrian explosion may have occurred much earlier than previously thought - Current events - University of Barcelona

Creationists have long misrepresented the so-called "Cambrian Explosion" as vindication of their belief in the spontaneous creation of complex multicellular life ex nihilo — as though organisms simply appeared, fully formed, without precursors. They portray it as an instantaneous event that defies evolutionary explanation, and falsely claim that it presents an insurmountable problem for evolutionary biology. In doing so, they even misquote the late Stephen Jay Gould, asserting that he admitted Darwinian evolution could not account for it and so invented the concept of "punctuated equilibrium" to paper over the cracks.

In a particularly striking display of cognitive dissonance, this version of events — supposedly occurring half a billion years ago — is frequently cited by the same creationists who insist the Earth is only 6,000 to 10,000 years old.

As is so often the case with creationist arguments, these claims are simply wrong. The Cambrian Explosion was not an instantaneous event, but a prolonged evolutionary process unfolding over some 10 million years, with evidence showing a transition from the static Ediacaran biota to the more mobile, complex organisms of the Cambrian. Gould, far from being an opponent of evolutionary theory, remained a staunch evolutionary biologist throughout his career. His now largely outdated concept of punctuated equilibrium was never an alternative to evolution, but rather an attempt to explain the appearance of abrupt change in the fossil record — a perception largely due to the compression of deep time in the geological column. When properly scaled, the fossil record easily accommodates the gradual evolution of complex traits.

Trace fossils are an indicator of the palaeoecological conditions in which the organism that generated them lived.

Now, new research by Olmo Miguez Salas of the University of Barcelona and Zekun Wang of the Natural History Museum in London has uncovered compelling evidence that pushes the roots of the Cambrian Explosion even further back in time. Their findings suggest that signs of mobility and bilateral body plans were already emerging within the Ediacaran biota. This extends the evolutionary runway leading into the Cambrian, giving more time for the radiation of novel body plans and for the development of evolutionary arms races—such as the emergence of predation, defence mechanisms, and sensory adaptations.

Their results are published in the journal Geology (paper here) and summarised in a news release from the University of Barcelona.

Creationism Refuted - Now It's Frozen Wolf Cubs From 4,000 Years Before 'Creation Week'

14,000-year-old frozen wolf cubs recovered from permafrost at the Syalakh site, Northern Siberia

Famous Ice Age ‘puppies’ likely wolf cubs and not dogs, study shows - News and events, University of York

The mountain of evidence that creationists must ignore to maintain their belief that Earth is a mere 6,000–10,000 years old—because it says so in a book of Bronze Age mythology—just got a little bigger. A new analysis of the DNA of two frozen canid cubs found in Siberian permafrost confirms they were wolves, not early domesticated dogs as once speculated. The cubs, discovered near the village of Tumat in northern Siberia, are around 14,000 years old and genetically similar to modern wolves.

An analysis of DNA from their stomach contents reveals a mixed diet of meat and plant matter, consistent with the diets of contemporary wolves. Remarkably, some of the meat—specifically skin—came from a woolly rhinoceros, likely a calf, as adult rhinos would have been far too large for wolves to hunt. An earlier study had identified black fur in the cubs, prompting speculation that they might be early domesticated dogs, since melanism is commonly associated with dogs but not typically seen in wolves. However, further genomic analysis showed that these cubs belonged to a now-extinct wolf population that was not ancestral to domestic dogs. This suggests the black fur mutation may have been limited to that specific lineage, contributing nothing to the modern dog gene pool.

The puppies were found at the Syalakh site, the first in 2011 and the second in 2015. The site also contains mammoth bones showing signs of burning and processing by humans. This initially led to speculation that the cubs might have been tame or semi-domesticated wolves associated with early humans. However, that hypothesis can now be ruled out based on the genetic evidence. It is believed that the cubs died when a landslide trapped them in their den shortly after their final meal.

How the wolf cubs came to be fed on the skin of a woolly rhinoceros remains uncertain, but one plausible explanation is that it was scavenged from a kill made by humans.

Refuting Creationism - Biofluorescent fish 112 Million Years Before 'Creation Week'.

A tropical striped triplefin, Helcogramma striata.

© John Sparks and David Gruber

Creationists bunker - Evidence keep out! No Science Allowed!

Studies Reveal Fish Biofluorescence Dates Back 112 Million Years | AMNH

I sometimes imagine creationists hiding inside a bunker with no windows, completely cut off from the reality outside, where a torrential rainstorm is underway. From within their sealed refuge, they declare to themselves—and to the world outside—that there is no evidence of rain, simply because they can’t see any.

Their only source of information is a handful of picture books depicting a tropical paradise where it never rains, so they believe everything beyond their bunker must be warm and sunny—just as the picture books describe. Anyone who tells them otherwise, or tries to show them a different picture, must be lying to trick them.

How else can creationists be so insulated from the reality of the deluge of scientific evidence in the real world?

That slightly tortured analogy is by way of introducing another couple of scientific papers concerning the evolutionary divergence of the phenomenon of biofluorescence. Unlike bioluminescence—where light is produced by a physiological process using ATP and functions in total darkness—biofluorescence involves the absorption of ambient light, which is then re-emitted at a different frequency. Specialised proteins absorb this light energy, become unstable in their excited state, and return to their ground state by releasing photons—hence biofluorescence functions in low-light conditions.

Fish in particular, but also sea turtles and corals, use these glowing patterns as signals—for attracting mates, confusing predators, and more. According to two newly published papers by a team led by researchers at the American Museum of Natural History (AMNH), this phenomenon first emerged around 112 million years ago—once again, firmly within Earth’s long pre–'Creation Week' history. Since then, biofluorescence appears to have evolved independently up to 100 times, a clear indication of its adaptive benefits in dimly lit ocean environments.

Beyond the evidence for biological activity in a time creationists claim the Earth didn’t even exist, there's another uncomfortable detail for them: the researchers declare that to understand the pattern of bioluminescence in nature, “...we need to understand the underlying evolutionary story...” Not something a creationist, labouring under the delusion that biologists are abandoning the theory of evolution in favour of creationism, would want to read.

Their findings are published open access in Nature Communications and PLOS ONE.

Creationism Refuted - A Giant Salamander - 5 Million Years Before 'Creation Week'

Reconstruction of Dynamognathus robertsoni

Matthew Inabinett

ETSU fossil discovery reveals giant ancient salamander

Unlike most of the palaeontology unearthed by science—which is often tens or even hundreds of millions of years older than Earth, according to creationist dogma—this discovery dates to a mere 5 million years ago. But the problem for creationists isn’t one of degree; it’s one of absolutes. If anything is older than Earth according to their doctrine, then that doctrine is simply wrong. It’s as straightforward as that.

Likewise, if even a single transitional or ancestral form exists, then the creationist insistence that such forms don't exist is demonstrably false.

Curiously, despite failing to grasp that binary logic, creationists continue to convince themselves that if they can cast doubt on even the tiniest detail of evolutionary science—perhaps a small gap in the fossil record or a question about a single species—then the entire edifice of modern biology collapses and “God did it!” triumphs by default, all without the faintest scrap of supporting evidence.

With that essentially childish view of how evidence and reasoning work, it will likely make no difference to their claims that a team of researchers from the Gray Fossil Site & Museum and East Tennessee State University (ETSU) have discovered the fossil of a comparatively large salamander dating back around 5 million years. This find sheds light on the explosive diversification of salamanders in what is now Appalachia some 12 million years ago. Today, Tennessee is home to about 50 species of salamander—roughly one in eight of all living species.

Refuting Creationism - How Living Organism's Survived - 700 Million Years Before 'Creation Week'

Researchers Ian Hawes of the University of Waikato and Marc Schallenberg of the University of Otago measure the physicochemical conditions of a meltwater pond.

Credit: Roger Summons

Pustular microbial mat section such as could have existend in small melt-water ponds.

When Earth iced over, early life may have sheltered in meltwater ponds | MIT News | Massachusetts Institute of Technology

Only by systematically ignoring geological and archaeological evidence can creationists continue to delude themselves into believing that Earth is just a few thousand years old and was perfectly created by an anthropophilic god especially for humans – its supposed “special creation.”

The evidence, however, paints a radically different picture from that childish superstition. Not only was Earth clearly not perfectly created for humans, it wasn’t perfectly created for any life form. And it is far older than creationists assert. In truth, around 600 million years ago, Earth was such a hostile place for life that it was entirely covered in ice. The polar ice sheets had extended until they met at the equator. These “Snowball Earth” conditions led to a mass extinction so severe that it remains something of a mystery how any life survived – especially complex eukaryotic cells.

Now, a multinational team of researchers led by scientists from the Massachusetts Institute of Technology (MIT) has found evidence that early life could have survived in small pools of surface meltwater. They reached this conclusion after studying similar meltwater pools on the McMurdo Ice Shelf in Antarctica. What they found not only showed that single-celled eukaryotes can survive in such conditions, but also revealed that the population of prokaryotes varies according to local environmental conditions

These meltwater pools act as microcosms of diverse environments and demonstrate how local factors shape the distribution of different species – exactly as predicted by the Theory of Evolution. Had the conditions been perfect as creationists insist, there could be no variation in the populations in these pools. Variation only arises because the species need to adapt to different conditions - something that would never be needed in perfectly designed conditions.

The team has just published their findings, open access, in the journal Nature Communications.

Malevolent Designer News - How Cold Sores Are Cleverly Designed To Maximise Suffering.

The human genome compacted inside cells
eight hours after infection.

Credit: Esther González Almela
and Álvaro Castells García

(Top) Cropped representative STORM-PAINT images of EdC-AF647 labeled hDNA (magenta), immunolabeled H3 (green), and their merge in mock and HSV-1 infected A549 cells. Scale bar: 2 µm. (Bottom) Zoomed-in regions are shown inside yellow boxes. Scale bar: 200 nm.

González-Almela, E., Castells-Garcia, A., Le Dily, F. et al. (2025)

Centre for Genomic Regulation Website

One of the many problems with Intelligent Design (ID) creationism is its complete failure to account for evolutionary arms races.

According to leading ID proponents like William A. Dembski and Michael J. Behe, living organisms and their parasites — including viruses — must have been intelligently designed because they are supposedly “irreducibly complex” and exhibit “complex specified information”. But if that were true, it would mean the same designer is deliberately crafting both parasites and the defence mechanisms their hosts use to fend them off — hardly the mark of a supremely intelligent creator.

A further problem, and one that creationists prefer to ignore, is theological: designing pathogens like viruses is fundamentally incompatible with the notion of a benevolent creator. In fact, it suggests a malevolent intelligence — one more concerned with maximising suffering than promoting life and maximising happiness. So, when science uncovers yet another example of a virus behaving with surgical precision and apparent ingenuity, ID creationists find themselves in a bind. Is irreducible complexity and complex specified genetic information not evidence of intelligent design after all? Or must they admit that the designer is, at best, morally indifferent — or worse, actively malevolent?

The latest headache for the ID camp comes courtesy of the Herpes simplex virus — the one responsible for cold sores. Researchers at the Centre for Genomic Regulation (CRG) in Barcelona, Catalunya, Spain, with colleagues in Guangdong Provincial People’s Hospital, Guangdong, China, have discovered that the virus can radically reorganise a host cell’s genetic architecture — and it does so using the host's own cellular machinery. Their findings have just been published open access in Nature Communications.

Refuting Creationism - Confirmation of A Denisovan Skull - Homo longi

A reconstruction of Homo longi from the ancient Harbin skull found in China.

Image credit: John Bavaro Fine Art
Science Photo Library

Figure 1 The geographic locations and proteomic profiles for the Pleistocene hominin individuals with palaeoproteomic data.

The Middle Pleistocene cranium recovered in Harbin, Heilongjiang Province, northeastern China.

Key Evidence Links Harbin Individual's Nearly Complete Skull to a Denisovan--Institute of Vertebrate Paleontology and Paleoanthropology.

One of the enduring problems with the Denisovans has been the lack of substantial physical evidence. Although their existence was first confirmed through DNA analysis of a finger bone discovered in the Denisova Cave in Siberia, and genetic traces of interbreeding with Homo sapiens are widespread throughout Southeast Asia and Melanesia—suggesting a remarkably adaptable and far-ranging hominin—fossil evidence has remained frustratingly scant. Beyond the Siberian finger bone, we have only a few bone fragments from a cave on the Tibetan Plateau and a jawbone dredged up by fishermen off the coast of Taiwan. These scattered remnants were insufficient to assign a clear taxonomic identity, so the group remained simply ‘the Denisovans’.

That gap in the fossil record now appears to have been dramatically narrowed. A near-complete skull, dubbed the 'Harbin skull'—also known as 'Dragon Man' or Homo longi—has now been identified as belonging to a Denisovan. This remarkable specimen, found in northeastern China, may finally give the Denisovans a face and, by the conventions of biological nomenclature, the name Homo longi. Since it is the most complete and morphologically distinct fossil now associated with the group, Homo longi may become the formal species name, superseding the informal label ‘Denisovan’.

Of course, Denisovans pose an even greater challenge to creationist dogma than they ever did to palaeoanthropology. Their existence is fundamentally at odds with the belief that all humans descend from a single ancestral couple who committed the so-called Original Sin, for which redemption is supposedly possible only through accepting the mythologised sacrifice of Jesus. The evidence now shows not only that there was no original couple, but that there wasn’t even a single founding species. Modern non-African humans are the product of complex interbreeding events between at least three archaic human lineages—thousands of years before the Earth was allegedly created, according to young-Earth creationist timelines.

The identification of the Harbin skull as Denisovan has just been published by researchers from the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China. Their findings appear in papers in Cell and Science, and in a news release from the Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology.

Refuting Creationism - How Dogs Spread Across The Americas - Then Survived The Legendary Biblical Global Flood

Chihuahua dog in Mexico.

Credit: Urvashi9, Getty Images

Figure 1. Distribution of archaeological samples analysed in this study.

Manin, Aurélie, et al (2025)

Ancient DNA reveals new clues about the incredible journey of dogs in the Americas | University of Oxford

According to the Bible, all living things outside Noah’s Ark were destroyed once Noah, his family, and his chosen animals were safely sealed inside (Genesis 7:4). This supposedly happened around 4,000 years ago, according to the biblical narrative — which creationists firmly believe to be inerrant history.

The snag is, the evidence simply doesn’t support that timeline—or a global flood involving mass extinction by drowning. Not only would such a flood have left a distinctive global deposit of sediment, containing a chaotic mix of ancient and modern animal and plant species from disconnected continents, but it would also have erased all archaeological traces of earlier civilisations and palaeontological evidence of past life. In effect, it would have reset the clocks of both archaeology and palaeontology to start around 4,000 years ago.

Unfortunately for biblical literalists, that’s not what we see. The predicted tell-tale layer of silt is conspicuously absent. Instead, both archaeology and palaeontology reveal a pattern of uninterrupted occupation of the planet by animals and humans stretching back tens of thousands—and, in the case of animal and plant species, hundreds of millions—of years. For anatomically modern humans, there is a consistent archaeological record documenting their spread across all land masses (except Antarctica), during which they domesticated animals such as dogs, which migrated alongside them.

One example of this pattern — the migration of domestic dogs with humans into the Americas between 7,000 and 5,000 years ago — has just been published in Proceedings of the Royal Society B, by an international team of scientists led by Dr Aurélie Manin from the School of Archaeology at the University of Oxford. They have shown that all South American dogs prior to the arrival of Europeans, trace their ancestry back to a single female. One strain — the Mexican Chihuahua - still shows evidence of that ancestry.

Refuting Creationism - A 600-Million-Year-Old Common Ancestor of Cnidarians and Bilaterians.

Adult polyp of the sea anemone Nematostella vectensis.

Grigory Genikhovich

Bodybuilding in Ancient Times: How the Sea Anemone Got Its Back

Childish creationist claims of a young Earth, the spontaneous magical generation of all living organisms without ancestry, and the supposed absence of evidence for the evolution of life from a common ancestor have taken another blow with the publication of compelling new research that refutes these basic creationist dogmas.

An open access paper published in Science Advances describes a candidate ancestral mechanism for establishing bilaterality — symmetry along a central axis — in both bilaterians (animals with bilateral symmetry) and the sea anemone Nematostella. The study, conducted by four researchers from the Department of Neurosciences and Developmental Biology at the University of Vienna, provides crucial insights into the deep evolutionary origins of body plan organisation.

It is also clear from both the paper and the researchers' explanation in a University of Vienna press release that they regard the Theory of Evolution as essential to interpreting their findings. Their discovery fits squarely within the evolutionary framework and aligns with the established timeline for the diversification of animal life from a common ancestor.

What Is Bilateral Symmetry? Bilateral symmetry is a body plan in which an organism can be divided into roughly mirror-image halves along a single plane—from head to tail. Most animals, including humans, insects, and vertebrates, display this type of symmetry.

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Why Is It Evolutionarily Significant?

• Directional Movement: Bilateral symmetry enables streamlined, forward-facing movement—ideal for seeking food, mates, and avoiding danger.
• Cephalisation: This symmetry is often associated with the development of a head region where sensory organs and the brain concentrate—an evolutionary advantage for processing information efficiently.
• Complexity and Specialisation: It allowed for greater internal organisation and the evolution of specialised body systems (e.g., digestive, nervous, and circulatory).

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Evolutionary Milestone

Bilateral symmetry is thought to have evolved over 600 million years ago in a common ancestor of all bilaterians. This innovation marked a major turning point in the history of life, leading to the vast diversity of animal forms we see today.

Bodybuilding in Ancient Times: How the Sea Anemone Got Its Back

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New insights into the evolution of the back-belly-axis.

A new study from the University of Vienna reveals that sea anemones use a molecular mechanism known from bilaterian animals to form their back-to-belly body axis. This mechanism ("BMP shuttling") enables cells to organize themselves during development by interpreting signaling gradients. The findings, published in Science Advances, suggest that this system evolved much earlier than previously assumed and was already present in the common ancestor of cnidarians and bilaterians.

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Most animals exhibit bilateral symmetry—a body plan with a head and tail, a back and belly, and left and right sides. This body organization characterizes the vast group known as Bilateria, which includes animals as diverse as vertebrates, insects, molluscs and worms. In contrast, cnidarians, such as jellyfish and sea anemones, are traditionally described as radially symmetric, and indeed jellyfish are. However, the situation is different is the sea anemones: despite superficial radiality, they are bilaterally symmetric – first at the level of gene expression in the embryo and later also anatomically as adults. This raises a fundamental evolutionary question: did bilateral symmetry arise in the common ancestor of Bilateria and Cnidaria, or did it evolve independently in multiple animal lineages? Researchers at the University of Vienna have addressed this question by investigating whether a key developmental mechanism called BMP shuttling is already present in cnidarians.

Shuttling for development

In bilaterian animals, the back-to-belly axis is patterned by a signaling system involving Bone Morphogenetic Proteins (BMPs) and their inhibitor Chordin. BMPs act as molecular messengers, telling embryonic cells where they are and what kind of tissue they should become. In bilaterian embryos, Chordin binds BMPs and blocks their activity in a process called "local Inhibition". At the same time, in some but not all bilaterian embryonic models, Chordin can also transport bound BMPs to other regions in the embryo, where they are released again – a mechanism known as "BMP shuttling". Animals as evolutionary distant as sea urchins, flies and frogs use BMP shuttling, however, until now it was unclear whether they all evolved shuttling independently or inherited it from their last common ancestor some 600 million years ago. Both, local inhibition and BMP shuttling, create a gradient of BMP activity across the embryo. Cells in the early embryo detect this gradient and adopt different fates depending on BMP levels. For example, in vertebrates, the central nervous system forms where BMP signaling is lowest, kidneys will develop at intermediate BMP signaling levels, and the skin of the belly will form in the area of maximum BMP signaling. This way, the body's layout from back to belly is established. To find out whether BMP shuttling by Chordin represents an ancestral mechanism for patterning the back to belly axis, the researchers had to look at bilaterally symmetric animals outside Bilateria – the sea anemones.

An Ancient Blueprint

To test whether sea anemones use Chordin as a local inhibitor or as a shuttle, the researchers first blocked Chordin production in the embryos of the model sea anemone Nematostella vectensis. In Nematostella, unlike in Bilateria, BMP signaling requires the presence of Chordin, so, without Chordin, BMP signaling ceased and the formation of the second body axis failed. Chordin was then reintroduced into a small part of the embryo to see if it could restore axis formation. BMP signaling resumed—but it was unclear whether this was because Chordin simply blocked BMPs locally, allowing a gradient to form from existing BMP sources, or because it actively transported BMPs to distant parts of the embryo, shaping the gradient more directly. To answer this, two versions of Chordin were tested—one membrane-bound and immobile, the other diffusible. If Chordin acted as a local inhibitor, both, the immobile and the diffusible Chordin would restore BMP signaling on the side of the embryo opposite to the Chordin producing cells. However, only diffusible Chordin can act as a BMP shuttle. The results were clear: Only the diffusible form was able to restore BMP signaling at a distance from its source, demonstrating that Chordin acts as a BMP shuttle in sea anemones—just as it does in flies and frogs.

A shared strategy across over 600 million years of evolution?

The presence of BMP shuttling in both cnidarians and bilaterians suggests that this molecular mechanism predates their evolutionary divergence some 600-700 million years ago.

Not all Bilateria use Chordin-mediated BMP shuttling, for example, frogs do, but fish don't, however, shuttling seems to pop up over and over again in very distantly related animals making it a good candidate for an ancestral patterning mechanism. The fact that not only bilaterians but also sea anemones use shuttling to shape their body axes, tells us that this mechanism is incredibly ancient. It opens up exciting possibilities for rethinking how body plans evolved in early animals.

Dr. David Mörsdorf, first author
Department of Neurosciences and Developmental Biology
University of Vienna, Vienna, Austria.

We might never be able to exclude the possibility that bilaterians and bilaterally symmetric cnidarians evolved their bilateral body plans independently. However, if the last common ancestor of Cnidaria and Bilateria was a bilaterally symmetric animal, chances are that it used Chordin to shuttle BMPs to make its back-to-belly axis. Our new study showed that.

Grigory Genikhovich, senior author.
Department of Neurosciences and Developmental Biology
University of Vienna, Vienna, Austria

Publication:

David Mörsdorf, Maria Mandela Prünster, Paul Knabl, Grigory Genikhovich.
Chordin-mediated BMP shuttling patterns the secondary body axis in a cnidarian.
Science Advances (2025) 11(24). DOI: 10.1126/sciadv.adu6347

Abstract Bone morphogenetic protein (BMP) signaling patterns secondary body axes throughout Bilateria and in the bilaterally symmetric corals and sea anemones. Chordin-mediated “shuttling” of BMP ligands is responsible for the BMP signaling gradient formation in many bilaterians and, possibly, also in the sea anemone Nematostella, making BMP shuttling a candidate ancestral mechanism for generating bilaterality. However, Nematostella Chordin might be a local inhibitor of BMP rather than a shuttle. To choose between these options, we tested whether extracellular mobility of Chordin, a hallmark of shuttling but dispensable for local inhibition, is required for patterning in Nematostella. By generating localized Chordin sources in the Chordin morphant background, we showed that mobile Chordin is necessary and sufficient to establish a peak of BMP signaling opposite to Chordin source. These results provide evidence for BMP shuttling in a bilaterally symmetric cnidarian and suggest that BMP shuttling may have been functional in the potentially bilaterally symmetric cnidarian-bilaterian ancestor.

INTRODUCTION
Bone morphogenetic protein (BMP) signaling acts in secondary body axis patterning across Bilateria, and its functions as morphogen have been studied in diverse animal species (1, 2). The mechanisms of the BMP-dependent axial patterning are similar between arthropods and vertebrates, indicative of the shared origin of the secondary, dorsoventral axis in protostome and deuterostome Bilateria, a notion strengthened once broader phylogenetic sampling became available (2–7). Intriguingly, the same mechanisms appear to regulate the secondary axis patterning in the bilaterally symmetric cnidarian Nematostella vectensis, indicating that a BMP-dependent secondary body axis may have evolved before the evolutionary split of Cnidaria and Bilateria [(8, 9), reviewed in (1, 10)]. However, a scenario in which BMP-mediated secondary axes evolved convergently in Bilateria and bilaterally symmetric Cnidaria is also possible (2).

BMPs are secreted signaling proteins of the transforming growth factor–β superfamily frequently acting as heterodimers (11–13). Signaling through the BMP receptor complex (Fig. 1A) results in phosphorylation and nuclear accumulation of the transcriptional effector SMAD1/5, which regulates the expression of many crucial developmental transcription factors and signaling pathway components [(14–18), reviewed in (19, 20)]. BMP signaling is tightly controlled by a plethora of intracellular (14, 21) and extracellular regulators (22–29) of which Chordin (= short gastrulation in insects) is, arguably, the most famous one. Like many other secreted BMP antagonists, Chordin binds BMP ligands, blocks the interaction with their receptor, and thereby inhibits BMP signaling (30). However, Chordin can also have pro-BMP effects and promotes long-range activation of BMP signaling in Drosophila, Xenopus, sea urchins, and in the sea anemone Nematostella (7, 31–34). The phylogenetic distribution of Chordin and two central BMP ligands, BMP2/4 and BMP5-8, and their importance for the secondary axis patterning across phyla suggests that, during early animal evolution, these molecules may have represented the minimum requirement for the formation of the bilaterally symmetric body plan (2, 10). However, to evaluate such a possibility, we need to understand the “mode of action” of BMPs and Chordin outside Bilateria, and our model, the sea anemone Nematostella, allows exactly that.

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Fig. 1. Possible modes of action of BMP signaling during axial patterning in Nematostella.

(A) BMP signaling pathway. BMP dimers bind the heterotetrameric receptor complex, resulting in the phosphorylation of SMAD1/5. pSMAD1/5 forms a complex with the Co-Smad SMAD4, which regulates transcription in the nucleus. Chordin binds BMPs preventing them from activating the receptor complex. Metalloproteases like Tolloid and BMP-1 cleave Chordin and release BMP ligands from the inhibitory complex in Bilateria. (B) Expression domains of BMPs and BMP antagonists in an early Nematostella larva. Oral view corresponds to the optical section indicated with grey dashed line on the lateral view. Pink circles show the nuclear pSMAD1/5 gradient. (C) The shuttling model suggests that in Nematostella, a mobile BMP-Chordin complex transports BMPs through the embryo. Receptor binding is inhibited in cells close to the Chordin source due to high concentrations of Chordin. On the opposite side of the directive axis, BMPs bind their receptors and activate signaling upon release from Chordin. Tolloid might be involved in the cleavage of Chordin and release of BMPs from the complex with Chordin also in Nematostella. (D) In the local inhibition model, Nematostella Chordin acts locally to inhibit BMP signaling and promote the production of BMP2/4 and BMP5-8 mRNA. Chordin mobility is not required for asymmetric BMP signaling.

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BMP signaling in Nematostella becomes detectable during early gastrula stage in a radially symmetric domain: The phosphorylated form of the BMP signaling effector SMAD1/5 (pSMAD1/5) is detected in the nuclei around the blastopore (14, 35). Shortly after the onset of BMP activity, the radial symmetry of the embryo breaks, establishing the secondary, “directive” body axis with minimum BMP signaling intensity detectable on the side of BMP2/4, BMP5-8, and Chordin expression and maximum BMP signaling on the side opposite to it (Fig. 1B) (14, 34, 35). The symmetry break occurs despite the fact that mRNAs of the type I BMP receptors Alk2 and Alk3/6 and the type II receptor BMPRII are maternally deposited (36) and remain weakly and ubiquitously expressed in the embryo (fig. S1) gradually developing a slight bias toward the “high pSMAD1/5” side of the directive axis by early planula stage (14). BMP2/4 and BMP5-8 are co-expressed in the late gastrula/early planula, and both these ligands are crucial for BMP signaling and directive axis patterning because knockdown of either ligand abolishes pSMAD1/5 immunoreactivity and completely radializes the embryo (34). Individual knockdowns of either BMP2/4 or BMP5-8 result in a strong up-regulation of transcription of both BMP2/4 and BMP5-8 in a radially symmetric domain showing that both these genes are negatively controlled by BMP signaling. Despite transcriptional up-regulation of BMP2/4 in BMP5-8 morphants and BMP5-8 in the BMP2/4 morphants, no nuclear pSMAD1/5 is observed in such embryos (9, 34, 35), suggesting that BMP2/4 and BMP5-8 signal as an obligate heterodimer during axial patterning in Nematostella.

The “core” BMPs, BMP2/4 and BMP5-8, are not the only BMP ligands present in the embryo at this stage. GDF5-like (GDF5L) is a BMP ligand expressed on the side of strong BMP signaling (Fig. 1B). GDF5L expression is abolished in the absence of BMP2/4 and BMP5-8, and the role of GDF5L appears to be in steepening the pSMAD1/5 gradient making it a “modulator” BMP (14, 34, 37). The BMP signaling gradient is stable over many (>24) hours during which it patterns the directive axis (9, 14, 34, 35, 37). Considering the short half-life of phosphorylated SMAD1/5 reported in other systems (15, 21), this indicates that long-range transport (~100 μm) of BMP2/4 and BMP5-8 and constant receptor complex activation is necessary to maintain BMP signaling. How it exactly happens that the core BMP ligands, BMP2/4 and BMP5-8, are expressed on one side of the embryo and the peak of BMP signaling activity is on the opposite side is currently unknown.

One possible explanation involves Chordin-mediated shuttling of BMP ligands, described in the dorsoventral patterning in Drosophila and Xenopus (7, 34, 38). In this model, Chordin inhibits BMP function locally, close to the Chordin source cells, but promotes long-range BMP signaling by forming a mobile complex with the BMP dimer, which is released once Chordin is cleaved by the metalloprotease Tolloid. The probability that this BMP dimer will bind its receptors rather than another, yet uncleaved Chordin increases with the distance to the Chordin source (Fig. 1C). In Nematostella, the shuttling model was proposed when we found that, unlike in all bilaterian models studied thus far, depletion of Chordin results in the loss of BMP signaling rather than in its enhancement (34). However, given that, in Nematostella, BMP signaling indirectly represses the transcription of the core BMPs, BMP2/4 and BMP5-8, and activates the transcription of the modulator BMP, GDF5-like (14), an alternative explanation is also possible: In this “local inhibition” scenario, Chordin locally represses BMP signaling enabling BMP2/4 and BMP5-8 production. BMP2/4 and BMP5-8 diffuse into the area of low or no Chordin (i.e., to the GDF5-like side of the directive axis) and bind the receptors there. In this scenario, Chordin knockdown results in a transient de-repression of the BMP2/4/BMP5-8–mediated signaling, which, in turn, leads to the repression of the BMP2/4 and BMP5-8 transcription. Because, in the absence of BMP2/4 and BMP5-8, GDF5-like expression is also lost (9), we may end in a situation when no BMP ligands are produced and no BMP signaling takes place, as it is the case in the Chordin morphant (9, 34). This local inhibition model, in which Chordin acts exclusively as a local repressor of BMP signaling (Fig. 1D), is similar to the situation in zebrafish, where extracellular mobility of Chordin is not required (39–41). Here, we address the role of Chordin in the BMP-dependent axial patterning in the sea anemone Nematostella and test these two alternative models.

David Mörsdorf, Maria Mandela Prünster, Paul Knabl, Grigory Genikhovich.
Chordin-mediated BMP shuttling patterns the secondary body axis in a cnidarian.
Science Advances (2025) 11(24). DOI: 10.1126/sciadv.adu6347

Copyright: © 2025 The authors.
Published by the American Association for the Advancement of Science. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

This discovery poses a significant problem for creationist claims because it provides clear molecular and developmental evidence for a shared evolutionary origin between animals with bilateral symmetry and simpler organisms like sea anemones, which lack such symmetry as adults. The fact that the genetic and developmental mechanisms for establishing a "back" or body axis predate the emergence of bilaterally symmetrical animals suggests that these features evolved gradually through modification of existing biological systems—not through sudden, miraculous creation.

Creationism relies on the assertion that complex body plans appeared abruptly, fully formed, and without evolutionary precursors. However, the findings in this study directly contradict that idea. They show that the genetic toolkit required for bilateral body structures was already present in the common ancestor of cnidarians (like sea anemones) and bilaterians and was likely repurposed and elaborated upon over millions of years. This is exactly what evolutionary theory predicts.

Moreover, the study aligns neatly with the established evolutionary timeline based on genetics, developmental biology, and the fossil record. There is no need to invoke supernatural causes or to assume that animals were created independently and without shared ancestry. Instead, the evidence points to deep continuity in the genetic architecture of life—a hallmark of common descent and a major blow to the isolated, one-off acts of creation claimed by young-Earth and Intelligent Design creationists alike.

Unintelligent Designer News - Designed a Cure For COVID-19; Gave It To LLamas - Or Is It Malevolence?

How the single domain antibody locks onto the spike protein’s base

Researchers identify new antibodies against current and future coronaviruses | VIB.BE - Home

Hot on the heels of the news that the putative intelligent designer behind creationism apparently devised a method to prevent the spread of cancer cells through the body—then handed it to the sea cucumber, a group of species not especially prone to cancer—comes another remarkable revelation.

It now appears that this same designer, if we accept the claims of ID creationists, has also developed a highly effective mechanism for disabling the SARS-CoV-2 virus that causes COVID-19. And once again, rather than bestowing this gift upon humans, the species most affected by the virus, the designer gave it to llamas — creatures not exactly known for their vulnerability to coronaviruses.

The mechanism in question involves relatively simple molecules known as single-domain antibodies, or VHHs—also referred to as nanobodies. These are much smaller than the conventional antibodies produced by most animals, including humans. They work by binding tightly to the virus’s spike proteins, effectively neutralising it by preventing it from prising open host cells and initiating infection. Even more impressively, these nanobodies appear to be broadly effective against a wide range of SARS-related coronaviruses.

While creationists might marvel at the ingenuity of such a designer, they would be hard-pressed to explain — or more likely, would simply ignore — why this supposedly anthropophilic intelligence chose not to equip humans with such a defence. Instead, it stood idly by as millions suffered and economies collapsed, despite having the ‘cure’ readily available.

This unique llama-specific mechanism was discovered by a team of researchers led by Prof. Xavier Saelens and Dr. Bert Schepens at the Flemish Institute for Biotechnology (Vlaams Instituut voor Biotechnologie) – University of Ghent (VIB-UGent) Center for Medical Biotechnology.

Refuting Creationism - Co-Evolution of Trees And Mastodons In South America

The extinct proboscidean species Notiomastodon platensis is observed feeding on Chilean palm fruit in La Campana National Park.

Author: Mauricio Álvarez

The disappearance of mastodons still threatens the native forests of South America - Universitat Autònoma de Barcelona - UAB Barcelona

Reconstruction of the paleoenvironments in which Chilean mastodons lived, from the semi-arid north to the cold rainforests of Patagonia.

Credit: Mauricio Álvarez

Just ten millennia ago, the mighty mastodons of South America played a crucial role in sustaining vast forests by spreading the seeds of large‑fruited trees—and now, new fossil evidence confirms that without these giants, entire ecosystems are crumbling [1, 2]. This groundbreaking research, published recently in Nature Ecology & Evolution, conclusively demonstrates that Notiomastodon platensis was an active frugivore based on detailed wear patterns and starch residues found in fossilised teeth [3].

For creationists who claim that life existed in its present form from the very beginning, this revelation is deeply unsettling. The discovery undermines the belief that forest ecosystems were always fully functional without the need for extinct megafauna—those massive mammals were not mere background actors but ecological engineers whose disappearance left communities of fruit‑bearing plants stranded, fragmented, and genetically impoverished.

Most strikingly, nearly 40 % of plant species once reliant on these now‑vanished seed spreaders are currently classified as threatened—up to four times the rate seen in regions still served by extant dispersers like tapirs or monkeys [2]. For creationists, this means that the natural world was far more dynamic—and far more dependent on evolutionary processes over deep time—than their models allow. If entire forests trebled on species interactions across thousands of years, then the simplistic view that everything was created perfectly, all at once, is seriously called into question.

A new study led by the University of O’Higgins, Chile, with key contributions from Institut Català de Paleoecologia Humana i Evolució Social, Centres de Recerca de Catalunya (IPHES-CERCA), demonstrates for the first time—based on direct fossil evidence—that these extinct elephant relatives regularly consumed fruit and were essential allies of many tree species. The researchers have just published their findings in the journal Nature Ecology & Evolution.

Creationism Refuted - How The Survivors of a Mass Extinction Evolved Into Dinosaurs

Euparkeria capensis, a small, 60 cm long reptile from the early Triassic period (245 - 237 million years ago).

Credit: Taenadoman, 2011
via Wikimedia Commons
CC A-SA 3.0

Triassic reptiles took 10,000 mile trips through “hellish” conditions, study suggests - University of Birmingham

Contrary to the child-like naivety and carefully cultivated ignorance of creationists, Earth is not — and never has been — a paradise perfectly designed for life, let alone tailor-made for humans. In reality, the vast majority of Earth's history — around 99.9975% of it — took place long before creationists believe the planet even existed, during which time the environment has frequently become so hostile that mass extinctions wiped out the majority of living species. Life as we know it today descends from the lucky few that managed to survive and adapt to radically altered conditions.

One of the most devastating of these extinction events was the end-Permian climate catastrophe, during which one group of reptiles — the archosauromorphs — managed to endure. From this resilient lineage emerged the dinosaurs, who would go on to dominate the planet until they too were annihilated by a cataclysmic meteor impact 66 million years ago.

While palaeontologists have long known about the survival and evolutionary significance of archosauromorphs, a lingering mystery remained: how did they manage to disperse across vast "dead zones" of the tropics, where temperatures were thought to be lethally high? A new study by researchers from the University of Birmingham and the University of Bristol has now shed light on this question. Their findings have been published, open access, in Nature Ecology & Evolution.

Malevolent Designer - Creationism's Putative Desiger Designed A Way to Prevent Cancer Spreading - And Gave It To Sea Cucumbers!

A sugar compound found in sea cucumbers could hold the key to stopping the spread of cancer, according to a recent UM-led study published in Glycobiology.

Graphic by Stefanie Goodwiller
University Marketing and Communications

Sea Cucumbers Could Hold Key to Stopping Cancer Spread | Ole Miss

Imagine you're a designer, and you've created a species — humans — for whom you have a particular fondness. Only, something keeps going dreadfully wrong with your blueprint. A large number of them keep dying because their cells become cancerous when they fail to replicate properly, and these cancers then spread to other organs, which ultimately give up the ghost.

Now, you can’t quite work out why these cancers start. For some reason, you've included substances called glycans on the surfaces of cells, and — just to complicate things — you’ve made cancer cells produce an enzyme called Sulf-2, which alters these glycans to help the cancer spread. Your solution? A stroke of genius: create another enzyme that inhibits Sulf-2. And lo! It works.

So, who do you give this life-saving enzyme to?

If you're creationism’s supposedly super-intelligent designer, you don’t give it to your favourite species — the one made in your own image, no less. No, instead you bestow this miracle molecule upon… sea cucumbers. A species that, incidentally, doesn’t even have a problem with cancer.

This, if they actually understood the subject properly, is what Intelligent Design creationists consider compelling evidence of a supremely intelligent designer.

The discovery that sea cucumbers possess this enzyme was made by researchers at the University of Mississippi and Georgetown University in Washington, DC. Their findings are published in the journal Glycobiology and can be read here.

It’s also neatly summarised in a University of Mississippi news article:

Refuting Creationism - How One Of Our Ancestral Species Travelled Across Eurasia

Simulations show Neanderthals likely traveled over 2,000 miles in just 2,000 years using natural corridors like rivers.

Credit: Shutterstock

Computer simulated paths of Neanderthal dispersals demonstrate they could have reached the Altai Mountains in Siberia within 2,000 years during warm climatic conditions in one of two ancient time periods—MIS 5e (approximately 125,000 years ago) or MIS 3 (approximately 60,000 years ago)—as demonstrated by the three different possible paths shown here. These paths follow a northern route through the Ural Mountains and southern Siberia, often intersecting with known archaeological sites from the same time periods.

Image: Emily Coco and Radu Iovita.

Anthropologists Map Neanderthals’ Long and Winding Roads Across Europe and Eurasia

One of the ancestral species of all non-African Homo sapiens, the Neanderthals, migrated across Eurasia from Central Europe to Central Asia between 120,000 and 60,000 years ago. In the Altai Mountains of Siberia, they encountered the Denisovans and interbred with them—just as they would later interbreed with Homo sapiens migrating northwards out of Africa some 20,000 years later.

This is the fascinating history of our cousin species, now being brought to light by researchers at New York University’s Centre for the Study of Human Origins.

It almost goes without saying that this, along with the very existence of Neanderthals and their interbreeding with Eurasian Homo sapiens, is entirely incompatible with basic creationist beliefs and a literal reading of the Bible. Like all scientific discoveries, however, it fits seamlessly with what we already know and further enriches our understanding of both Neanderthal life and our own evolutionary history.

The discovery also addresses one of the long-standing mysteries surrounding Neanderthal dispersal during the Ice Age—namely, how they migrated from their central European ‘homelands’ to the Altai Mountains in Central Asia, where they interbred with Denisovans in what was likely the northern limit of the Denisovans’ range. Until now, their migration route had remained unclear due to a lack of archaeological evidence.

The breakthrough comes from computer simulations, which reveal a network of habitable valleys that connected Central Europe to Central Asia during a warmer period lasting some 2,000 years—long enough for Neanderthals to have reached within 600 kilometres of the Altai Mountains. The New York anthropologists have recently published their findings in the journal PLOS One.

Refuting Creationism - Co-Evolution of Humans and Influenza Viruses - Just as the TOE Predicts

AI-generated image (ChatGPT4o)

H3N2 virus is a respiratory viral infection of the influenza A virus.

Large-scale immunity profiling grants insights into flu virus evolution | For the press | eLife

In a striking confirmation of evolutionary theory—and a clear rebuttal of several fundamental creationist claims—scientists have demonstrated a close correlation between population-level immunity and the evolution of influenza viruses to evade that immunity. The findings, reported in eLife, align perfectly with predictions made by evolutionary biology: as the immune landscape of a population shifts, so too does the genetic makeup of viruses in an ongoing evolutionary arms race.

Disappointingly for creationists hoping for signs that biomedical science is abandoning evolution in favour of supernatural explanations, there is no such evidence. Nowhere in the study is there a hint that scientists are retreating from evolutionary principles or embracing a non-falsifiable belief system involving mysterious, unexplained entities. On the contrary, the researchers are clear and unequivocal: their results reinforce the view that viral evolution is a dynamic, adaptive process shaped by natural selection in response to host immunity.

Even more troubling for proponents of Intelligent Design (ID) is the unavoidable implication that the viral mutations observed in this study constitute what William A. Dembski calls "complex specified information"—which he argues can only arise through the intervention of an intelligent designer. If one follows that line of reasoning, the logical (if deeply uncomfortable) conclusion is that this designer is actively modifying viruses to undermine the very immune systems it supposedly created to protect us. Such behaviour can hardly be described as intelligent and is incompatible with the benevolent deity so often associated with the Intelligent Design movement.

How Evolution Works - Co-opting Old Genes For New Functions

Liverworts lacking a gene called RLF have severe deformations in various organs (three plants pictured right and bottom), demonstrating that RLF is involved in organ development in these basic land plants as well.

© FUKAKI Hidehiro (CC BY)

Molecular phylogenetic tree of the REDUCED LATERAL ROOT FORMATION (RLF) protein family. The unrooted molecular phylogenetic tree was constructed based on amino acid sequences of RLF and CB5A, B, C, D, E, and LP from various plant species.

Iwata, K.P., Shimizu, T., Sakai, Y.,et al(2025)

A root development gene that’s older than root development | Kobe University News site

One common way creationist apologists attempt to mislead the scientifically uninformed is by claiming that the Laws of Thermodynamics are somehow relevant to the evolution of information within a species' genome. They argue that any increase in genetic information would violate both the Second and Third Laws of Thermodynamics—asserting that increased biological complexity equates to a decrease in entropy (disorder), and that new information is akin to energy and thus cannot increase due to the Law of Conservation.

This argument is fundamentally flawed on several levels but continues to be repeated despite being repeatedly refuted by both biologists and physicists. First, it completely ignores the fact that Earth is not a closed system. The input of energy from the Sun, for example, allows local decreases in entropy (such as in the formation of complex biological structures) while the total entropy of the universe still increases, fully complying with the Second Law. The Third Law, which relates to the entropy of systems at absolute zero, is entirely irrelevant to biological evolution.

Second, the idea that genetic information is conserved like energy is a misrepresentation. Genetic information can and does change in multiple ways through mutation. A mutation can involve the loss of information (e.g. deletion of a DNA segment), a change in information (e.g. substitution of one or more nucleotides), or an increase in information (e.g. insertion of additional sequences, or the movement of transposable elements—“jumping genes”—to new locations in the genome). None of these processes require a change in the total amount of matter or energy; they simply involve the rearrangement of existing molecular components. Any local increase in biological order is offset by energy expenditure elsewhere, typically via the hydrolysis of ATP to ADP and phosphate within metabolic pathways.

Moreover, these objections rest on the false assumption that evolution is about the quantity of information. In reality, it is the function and meaning of genetic information that drives evolutionary change. A sequence of DNA that once encoded a protein with one function can, through mutation and natural selection, take on a new function entirely—a process known as exaptation.

A well-known example is the evolution of the mammalian middle ear bones. In ancestral fish, certain jawbones played a structural role in the jaw joint. Over time, in early synapsids, these bones were repurposed and miniaturised to become part of the auditory system, transmitting sound vibrations from the eardrum to the cochlea.

Creationism Refuted - Exquisite Fossils From 226 Million Years Before 'Creation Week'

The Karoo Basin is a rich source of fossils for the Permian Period of life.

Image © WOLF AVNI/Shutterstock

Other life of this time included the lizard-like ancestors of tortoises, large amphibians that lurked like crocodiles just below the water surface, and forests dominated by a tree called Glossopteris with an understorey of spore-producing plants such as mosses, ferns and horsetails.

Photo: PEXELS

Exquisite new fossils from South Africa offer a glimpse into a thriving ecosystem 266 million years ago

In the realm of palaeontology, few discoveries are as illuminating as those that offer a window into ecosystems long vanished. A recent study published in The Conversation by palaeontologist Rosemary Prevec of Rhodes University, South Africa, unveils such a discovery: an exquisitely preserved fossil site in South Africa's Northern Cape province, dating back 266 million years to the middle Permian period. This site reveals a thriving ecosystem teeming with diverse plant life and a myriad of insect species, providing an unprecedented glimpse into pre-dinosaur terrestrial life.[1]

The significance of this find extends beyond its immediate scientific value; it directly challenges fundamental creationist assertions. By presenting concrete evidence of complex ecosystems existing millions of years before the advent of humans, it undermines the young-Earth creationist timeline that posits a 6,000 to 10,000-year-old Earth. The detailed stratigraphy and radiometric dating techniques employed corroborate the Earth's ancient history, aligning with the broader scientific consensus on geological and biological evolution.

Moreover, the discovery underscores the continuity and gradual progression of life forms, countering the notion of sudden creation. The intricate details preserved in these fossils—ranging from delicate insect wings to diverse plant structures—highlight the complexity and diversity of life well before the emergence of humans. Such findings reinforce the evolutionary narrative of life's development over hundreds of millions of years, offering tangible evidence against creationist models that reject evolutionary theory.

Rosemary Prevec's article in The Conversation is reprinted here under a Creative Commons licence, reformatted for stylistic consistency:

Unintelligent Design - Why Your Toothache Has Ancient Origins - In Your Ancestral Fish

Artistic rendering of the sensory exoskeletons of the early jawless vertebrate Astraspis being attacked by the sea-scorpion Megalograptus in dark shallow waters.

Brian Engh

CT scan of the front of a skate, showing the hard, tooth-like denticles on its skin (shown in orange).

Yara Haridy

Toothache from eating something cold? Blame these ancient fish | Biological Sciences Division | The University of Chicago

Have you ever taken a mouthful of ice cream or cold water, only to be rewarded with a sudden, stabbing pain in your teeth? It vanishes in a few seconds, but for that brief moment, it’s excruciating.

You might wonder what kind of intelligent designer would produce such a feature—one that serves no apparent purpose other than to make you suffer. The answer, of course, is that it wasn’t designed at all.

Like so much else about the human body, the sensitivity of our teeth is the product of evolution—a long, meandering process shaped not by foresight or intent, but by whatever natural selection happened to favour at the time. That over-sensitive layer of dentine beneath the enamel traces its origins back to ancient jawless fish, whose bony body armour included sensory structures capable of detecting changes in their environment. These structures were crucial for survival and heavily favoured by selection.

As evolution repurposed this structure over millions of years—eventually becoming part of our teeth—there was no strong selection pressure to reduce its sensitivity. In the aquatic world of those primitive fish, a keen sensory system might have meant the difference between life and death. In modern humans, however, it serves no meaningful function. A momentary sting when we drink something cold doesn’t affect our survival or reproductive success, so we’re left with a redundant sensory feature that occasionally causes pain.

If ever there were a perfect illustration of how evolution works—and why no intelligence is required—this is it. Unless, of course, you believe the designer in question is a malevolent deity with a particular interest in toothaches.

The discovery of this direct connection with our remote ancestral past was made by researchers at the University of Chicago who have just published their findings, open access in Science.