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Fossil Friday: The Explosive Origin of Complex Eyes in Trilobites

Photo credit: Günter Bechly.

This Fossil Friday features a fossil from my own collection, a phacopid trilobite from the Devonian of Morocco. Note the remarkable preservation of the prominent compound eyes.

A recent work by Schoenemann (2021) provided a “comprehensive overview about what is known about trilobite eyes and their functioning after more than 120 years of intense research on this topic.” The author mentioned that trilobites “appeared close to the very beginning of the Cambrian Explosion” and “formed an important component of the Great Ordovician Diversification Event,” two events that have both been called ‘Big Bangs‘ of life. Schoenemann found that “the trilobite has no physical predecessor here” and “they are equipped from the very beginning of their appearance in the fossil record with elaborate compound eyes.” This confirms exactly what ID proponents like Stephen Meyer and myself have emphasized all the time. Schoenemann also describes how “the diversity of the morphology of trilobite eyes ‘explodes’ with the Ordovician”, which does not really sound like a gradual development in a Darwinian way. While some of the different types of trilobite eyes could at least theoretically be  “achieved by modifications of the common principle of an original holochroal eyes,” the highly specialized schizochroal eyes of phacopids “show up as not being apposition eyes,” which requires a major re-engineering that certainly involved multiple coordinated mutations that imply a waiting time problem. Therefore, the abrupt origin of such biological innovations defies a Darwinian explanation, because the numbers do not add up. Another new study by Schoenemann et al. (2021) even reinforced this problem. They could show that phacopid eyes indeed represent a unique type of hyper compound eyes, where tens to hundreds of small compound eyes are each covered with a single lens. Nothing remotely similar is found among any of the other millions of arthropods or anywhere else in the animal realm.

A Phylogenetic Scenario

In a supplementary file the authors suggested a phylogenetic scenario for the origin of the different eyes in arthropods, but their figure rather emphasizes the anatomical gulf between the different constructions. The authors can offer no plausible explanation how such transitions could have been achieved, beyond embarrassingly superficial speculations that there could be genetic programs that “simply produced” these structures. It is a general pattern in evolutionary biology that so-called explanations follow the pattern ‘because evolution is true there may have been an imagined process X that made it happen’. That‘s hardly better than explaining the phenomenon that opium makes sleepy with an imagined dormitive power, which was already ridiculed by French playwright Molière (1673). Exercises in begging the question and fancy just-so storytelling dominate the field of evolutionary biology, while any rigorous hypotheses are conspicuously lacking, which is why I as a former evolutionary biologist have come to the conclusion that this discipline does not qualify as true science.

Another Interesting Fact

But there is another interesting fact that is worth mentioning: Even though there are gazillions of perfectly preserved trilobite fossils, which provide detailed information about their complete anatomy, including soft tissues and the intricate internal construction of their compound eyes, Schoenemann (2021) admitted that “still today the phylogenetic position is vigorously debated” with hardly any consensus beyond the trivial fact that they are (eu)arthropods. Darwinists should expect that with sufficient anatomical information any organism can be easily placed in the tree of life because homologous similarities should be a reliable guide to reconstruct common ancestry and phylogenetic relationship. The enormous controversies among biologists about conflicting phylogenetic evidence and incompatible tree reconstructions show that the Darwinian expectation commonly fails the litmus test of reality. Luckily the theory has been made immune to empirical falsification because it is simply assumed to be true by default as the only viable option for materialists. This kind of immunization against falsification combined with the demonization of any skeptics is another hallmark of pseudoscience.


  • Schoenemann B 2021. An overview on trilobite eyes and their functioning. Arthropod Structure & Development 61:101032, 1-14. DOI: https://doi.org/10.1016/j.asd.2021.101032
  • Schoenemann B, Clarkson ENK, Bartels C, Südkamp W, Rössner GE & Ryck U 2021. A 390 million-year-old hyper-compound eye in Devonian phacopid trilobites. Scientific Reports 11:19505, 1-10. DOI: https://doi.org/10.1038/s41598-021-98740-z