Rosa Rubicondior: Refuting Creationism - Oldest-Known Evolutionary Arms Race in the Cambrian

Oldest-Known Evolutionary “Arms Race” in the Cambrian | AMNH

Examples of Lapworthella fasciculata shells (under scanning electron microscope) from the Mernmerna Formation, Flinders Ranges, South Australia showing holes made by a perforating predator. Scale bars represent 200 micrometers.

R. Bicknell, et al (2025)

Perhaps Creationism's designer god is just a slow learner.

Anyone with an intellect greater than that of a plank should be capable of understanding the utter futility and waste in an arms race in which the strategy is to keep running faster just to stay in the same place. Arms races only make sense as the result of a game plan in which you can't communicate with your opponent and have no way of telling what he or she is thinking and if they gain the upper-hand, you lose. The only safe choice is to up the stakes - and that goes for your opponent too.

It becomes even more incomprehensible if the person you're having the arms race with is yourself, unless you're an amnesic with multiple personality disorder, and yet, if we believe creationists, that's exactly what their putative designer god is doing constantly.

Everywhere we look in nature, organisms are competing with one another for resources, or because one is trying to exploit the other as a food source in a predator-prey relationship or as a parasite trying to live in or on another organism and even killing it or making it weak and sickly as a byproduct of its parasitism. And yet creationists insist there is only one designer designing both sides in these arms races.

For some unfathomable reason, creationists like to imagine the idea of a celestial idiot having arms races with itself in millions of relationships in nature is a much better explanation than these arms races being the inevitable result of mindless evolutionary processes where a slight improvement increases the chances of leaving descendants while reducing the chance of the opponent doing the same, so creating a selection pressure for the next twist in the spiral.

What information do you have on Lapworthella fasciculata from the Cambrian? Lapworthella fasciculata is an extinct species from the Cambrian period, classified within the group of small shelly fossils (SSF). These organisms are known primarily from their fossilized, tubular or conical shells made of calcium phosphate or calcium carbonate. Lapworthella is a genus within the problematic group of early skeletal metazoans, meaning their exact phylogenetic placement remains uncertain due to limited and fragmentary fossil evidence.

Key Characteristics of Lapworthella fasciculata:

Morphology: The fossil typically consists of tubular or conical skeletal elements, often with a radiating, fasciculate (bundle-like) arrangement.
Composition: The shells are usually phosphatic, which contributed to their preservation in Cambrian sediments.
Ecology: It was likely a benthic organism, possibly sessile, attaching to the substrate or existing as part of microbial mats.
Significance: As part of the SSF assemblage, Lapworthella provides insight into the Cambrian explosion, a period of rapid diversification of animal life. Its structure suggests early experimentation with mineralized skeletons in metazoans.
Phylogenetic Affinities:

The exact evolutionary relationships of Lapworthella fasciculata remain unresolved. Some studies propose it might be related to early lophotrochozoans, though it could also represent a now-extinct lineage of basal metazoans.
Its unique morphology adds to the diversity of small shelly fossils that illustrate early animal skeletal innovations.

But if we believe creationists, it seems this idiocy has been going on at least since the Cambrian according to the discovery by a team led by researchers at the American Museum of Natural History who think they have discovered the first instance of an arms race. They have just published their findings in the journal Current Biology and have given details in an American Museum of Natural History press release:

Study Reveals Oldest-Known Evolutionary “Arms Race”
A new study led by researchers at the American Museum of Natural History presents the oldest known example in the fossil record of an evolutionary arms race. These 517-million-year-old predator-prey interactions occurred in the ocean covering what is now South Australia between a small, shelled animal distantly related to brachiopods and an unknown marine animal capable of piercing its shell. Described today in the journal Current Biology, the study provides the first demonstrable record of an evolutionary arms race in the Cambrian.

Predator-prey interactions are often touted as a major driver of the Cambrian explosion, especially with regard to the rapid increase in diversity and abundance of biomineralizing organisms at this time. Yet, there has been a paucity of empirical evidence showing that prey directly responded to predation, and vice versa.

Dr. Russell D.C. Bicknell, lead author Palaeoscience Research Centre
School of Environmental and Rural Science
University of New England, Armidale, NSW, Australia.

An evolutionary arms race is a process where predators and prey continuously adapt and evolve in response to each other. This dynamic is often described as an arms race because one species’ improved abilities lead to the other species improving its abilities in response.

Bicknell and colleagues from the University of New England and Macquarie University—both in Australia—studied a large sample of fossilized shells of an early Cambrian tommotiid species, Lapworthella fasciculata, from South Australia. More than 200 of these extremely small specimens, ranging in size from slightly larger than a grain of sand to just smaller than an apple seed, have holes that were likely made by a hole-punching predator—most likely a kind of soft-bodied mollusk or worm. The researchers analyzed these specimens in relation to their geologic ages, finding an increase in shell wall thickness that coincides with an increase in the number of perforated shells in a short amount of time. This suggests that a microevolutionary arms race was in place, with L. fasciculata finding a way to fortify its shell against predation and the predator, in turn, investing in the ability to puncture its prey despite its ever-bulkier armor.

This critically important evolutionary record demonstrates, for the first time, that predation played a pivotal role in the proliferation of early animal ecosystems and shows the rapid speed at which such phenotypic modifications arose during the Cambrian Explosion event.

Dr. Russell D.C. Bicknell.

Highlights

The oldest empirical evidence of a predator-prey arms race in the fossil record.
Cambrian prey species could reinforce their shells over time when frequently attacked.
Cambrian predators could effectively respond to enhanced prey defenses.
Summary
Predation is an important driver of species-level change in modern and fossil ecosystems, often through selection for defensive phenotypes in prey responding to predation pressures over time.^{1,2,3,4,5,6,7,8} Records of changes in shell morphology and injury patterns in biomineralized taxa are ideal for demonstrating such adaptive responses.^9,10,11 The rapid increase in diversity and abundance of biomineralizing organisms during the early Cambrian is often attributed to predation and an evolutionary arms race.^{12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27} A Cambrian arms race is typically discussed on a macroevolutionary scale, particularly in the context of escalation.^12,27,28,29 Despite abundant fossils demonstrating early Cambrian predation, empirical evidence of adaptive responses to predations is lacking. To explore the Cambrian arms race hypothesis, we assessed a large sample of organophosphatic sclerites of the tommotiid Lapworthella fasciculata from a lower Cambrian carbonate succession in South Australia,^30,31,32 >200 of which show holes made by a perforating predator.^33,34 Critically, the frequency of perforated sclerites increases over time, with a combination of time-series analyses and generalized linear models suggesting a positive correlation with sclerite thickness. These observations reflect a population-level adaptive response in L. fasciculata and the oldest known microevolutionary arms race between predator and prey. Propagation of such interactions across early Cambrian ecosystems likely resulted in the proliferation of biomineralizing taxa with enhanced defenses, illustrating the importance of predation as a major ecological driver of early animal evolution.^12,14,20,35

Bicknell, Russell D.C.; Campione, Nicolás E.; Brock, Glenn A.; Paterson, John R.
Adaptive responses in Cambrian predator and prey highlight the arms race during the rise of animals
Current Biology(1025) DOI:10.1016/j.cub.2024.12.007

© 2025 Elsevier.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.

Probably as upsetting for creationists as this news that their putative designer had lost its marbles 500 million years ago, is the news that these predator-prey arms races were probably responsible for the 'explosive' radiation in body forms that creationist frauds frequently try to present as happening in a single act of creation, even though we know it took 6-10 million years. There are, of course, fewer more powerful forms of natural selection than the immediate threat of becoming something's dinner unless you can avoid it, so we had a proliferation of defensive structures and strategies such as burrowing and a proliferation of predators with improved means of capturing prey, such as large jaws, improved mobility, etc.

All explainable by a perfectly rational natural process with no need for the intervention of a magic raving lunatic.

For many more examples of evolutionary arms races and why they refute creationism, see my book, Unintelligently Designed Arms Races: How Nature Refutes Intelligent Design

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