Reasons to Believe

The Cambrian Explosion and Evolutionists’ Responses

Whether I speak at a church, a university, a seminary, or a research firm, during the Q&A time I am inevitably asked about the Cambrian explosion. I also get emails about the Cambrian explosion. Here is an an example from our inbox and my answer:

Q: Have evolutionists come up with any valid explanation for the sudden appearance of the Cambrian explosion? 

A: The Cambrian explosion refers to the sudden, simultaneous appearance of most of the animal phyla (body plans) that occurred 542–543 million years ago. Ten of the many challenges the Cambrian explosion poses to evolutionary explanations for life are as follows:

  1. While evolutionary scenarios, as opposed to worked-out theories, exist for hypothesizing how new genera, new orders, and new families of animal life might appear, there is no rational evolutionary scenario for explaining how a new animal phylum might appear.
  2. From 50 to 80 percent of the animal phyla known to have existed at any time in Earth’s history appeared within no more than a few million years of one another, as the Cambrian geological era began.
  3. Of the 182 animal skeletal designs theoretically permitted by the laws of physics, 146 appear in the Cambrian explosion fossils.
  4. The Cambrian explosion marks the first appearance of animals with skeletons, bilateral symmetry, appendages, brains, eyes, and digestive tracts that include mouths and anuses.
  5. Virtually every eye design that has ever existed appears simultaneously in the Cambrian explosion.
  6. The moment oxygen levels in Earth’s atmosphere and oceans permit the existence of Cambrian animals, they suddenly appear.
  7. The Cambrian explosion occurs simultaneously with the drastic change in sea chemistry known as the Great Unconformity.
  8. The Cambrian explosion includes the most advanced of the animal phyla, chordates, including vertebrate chordates.
  9. Both bottom-dwellers and open ocean swimmers appear simultaneously in the Cambrian explosion.
  10. Optimization of the ecological relationships among the Cambrian animals, including predator-prey relationships, occurred without any measurable delay.

These challenges and several more are documented and described in some depth in chapter 13 of my new book, Improbable Planet (releasing September 2016).

The world’s leading experts on the Cambrian explosion are aware of just how profound and intractable these challenges are to any conceivable evolutionary explanation for the Cambrian explosion. Here are a few of their in-context quotes from their research papers:

“No single environmental or biological explanation for the Cambrian explosion satisfactorily explains the apparent sudden appearance of much of the diversity of bilaterian animal life.”1

—Jeffrey Levinton (marine ecologist, evolutionary biologist)

“The Cambrian ‘explosion’ of body plans is perhaps the single most striking feature of the metazoan fossil record. The rapidity with which phyla and classes appeared during the early Paleozoic coupled with much lower rates of appearance for higher taxa since, poses an outstanding problem for macroevolution.”2

—Gregory Wray (evolutionary biologist)

“Elucidating the materialistic basis of the Cambrian explosion has become more elusive, not less, the more we know about the event itself.”3

—Kevin Peterson et al. (evolutionary biologists)

You will find more such quotes in chapter 13 of Improbable Planet. To be clear, I am not saying you will not find evolutionary biologists who claim to have an evolutionary explanation for the Cambrian explosion. I have met several. However, those that claim to have an explanation deny the suddenness of the event and the rapidity of its occurrence relative to the physical and chemical events that first make the existence of these animals possible. Typically, they assert that the Cambrian animals appeared in gradually more advanced forms over the course of 40–50 million years. Those evolutionary biologists who are aware of the data establishing the challenges listed above acknowledge that the challenges defy all macroevolutionary models.

Evolutionary biologists who do recognize the failure of evolutionary models to explain the Cambrian explosion often counter those of us who are evangelical Christian research scientists by asking us why God would choose to create Cambrian animals at the time and place that he did. The answer that I document and describe at some length in Improbable Planet is that unless God created the Cambrian animals in the greatest possible diversity at the greatest possible abundance levels at the earliest time permitted by the laws of physics and the history of the universe, human beings and human civilization would be impossible. God’s desire to create a home for human beings where humans could launch and sustain civilization explains why the Cambrian explosion looks the way it does.


  1. Jeffrey S. Levinton, “The Cambrian Explosion: How Do We Use the Evidence?,” BioScience 58 (October 2008): 855, doi:10.1641/B580912.
  2. Gregory A. Wray, “Rates of Evolution in Developmental Processes,” American Zoologist 32 (February 1992): 131, doi:10.1093/icb/32.1.123.
  3. Kevin J. Peterson, Michael R. Dietrich, and Mark A. McPeek, “MicroRNAs and Metazoan Macroevolution: Insights into Canalization, Complexity, and the Cambrian Explosion,” BioEssays 31 (July 2009): 737, doi:10.1002/bies.200900033.


Subjects: Animals, Evolution, Genesis, Naturalism