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Fossil Friday: Did the Cambrian Explosion Really Happen?

Photo: Trilobite Redlichia, Cambrian of China, Dlloyd via Wikimedia, CC BY-SA 3.0.

When confronted with the argument from the sudden appearance of animal body plans in the Cambrian Explosion about 540-515 million years ago (e.g., early arthropods like the featured trilobite Redlichia), the newest fad among anti-ID activists and hardcore Darwinists is to boldly deny that this event ever happened. A good example is the silly rant by YouTuber Dave Farina against Stephen Meyer’s book Darwin’s Doubt. These deniers of the well-established scientific consensus rest their argument on the recent publications of a few maverick paleontologists, who indeed made similar claims about the Cambrian Explosion and the Great Ordovician Biodiversification Event being nothing but a mirage, i.e., an artifact of incomplete preservation, undersampling, and sampling bias. I have already responded to several such claims in previous articles (e.g., Bechly 2022a2022b) and have shown why they are unconvincing and based on obfuscating language and ambiguous redefinition of common terms.

No Reasonable Doubt

I also established in my articles with numerous quotes from up-to-date peer-reviewed scientific literature that there is no reasonable doubt about the reality of the Cambrian Explosion and its status as a fatal problem for Darwinism (also see these articles by Luskin 2013Luskin 2023 and Coppedge 2023).

Now, a new study by the above-mentioned team of maverick authors (Servais et al. 2023) has regurgitated the revisionist views, and this was of course accompanied by sensational press releases with catchy headlines like “Did the Cambrian explosion really happen?” (Heidt 2023). The main claims of this paper are:

  • The early Palaeozoic accommodated a single long-term radiation.
  • Continental fragmentation exerted a first-order control on this long-term radiation.
  • The Cambrian biodiversification was not a sudden burst (“explosion”) of diversity.
  • The Great Ordovician Biodiversification “Event” was not a single “event.”
  • Terms such as “radiation” or “biodiversification” are more suitable terms.

The general fallacy of this paper is the conflation of the traditional understanding of the Cambrian Explosion as the sudden appearance of animal body plan disparity with the mere rate of biodiversification in terms of species diversity more or less continuously increasing from the Cambrian to the Ordovician. In other words: They are knocking down straw men.

But It Get’s Worse

In fact, the real data do not support their main point at all. What the scientists did in this study is simply screen two large paleontological databases, which collectively contain about 2 million entries about fossil biodiversity. Based on these data, which actually contradict their thesis, “the authors assert that these resources aren’t truly global …” and claim that “Were they to put the same effort into studying this period, the existence of two individual events would likely melt away” (Servais quoted in Heidt 2023). This is of course nothing but ad hoc special pleading and mere speculation about potential biases to explain away the inconvenient actual data. It is fishy indeed and suggests that the whole point of this endeavor is the protection of Darwinian evolution against empirical evidence. It certainly isn’t solid science!

So, it is hardly suprising that other experts remain utterly unconvinced and object that “there is actually quite good evidence that there was a Cambrian explosion, as we would typically call it” (Nanglu quoted in Heidt 2023). This will of course not prevent our dear opponents from misrepresenting the new paper as alleged proof that science has shown that the Cambrian Explosion never happened. Cherry picking and confirmation bias anyone?