Why did so many complex creatures appear so suddenly in the Cambrian Period? And what does this mean for how we think about life’s origins?
The Cambrian Period remains one of the most puzzling episodes in Earth’s history. In a geological instant, multicellular life forms appeared in astonishing diversity. Charles Darwin admitted in 1859 that this “Silurian problem” (as the rocks were then called) posed a challenge to gradual evolution. If life branched slowly through countless transitions, why are so few visible in the record? The question is still relevant.
Competing Perspectives
The Intelligent Design Argument
Proponents of intelligent design (ID) argue that DNA functions like digital code. To build new body plans, organisms require vast amounts of information, far more than random mutations could plausibly generate. For ID, the informational architecture of life points to the work of a mind rather than chance.
The Evolutionary Response
Evolutionary biologists counter that ID overlooks new genetic insights. For instance, animal body plans do not require entirely new genes. Instead, existing “tool kit” genes can be reused and “rewired” through cis-regulatory elements—regions of DNA that act like switches, turning genes on and off in precise ways.
Think of cis-regulatory elements as an orchestra. The instruments (genes) remain largely the same, but the conductor (the regulatory network) changes how and when each instrument plays, creating new symphonies of form. This explains how body plans might arise through modifications in timing and control, rather than the invention of endless new genes.^1
Recent paleontological discoveries complement this view. For example, new sponge fossils from Utah demonstrate the early establishment of complex body plans like the hexactinellid sponges during the Cambrian.^2 These finds show that Cambrian diversity included both “new” organisms and recognizable lineages with enduring architectures.
At the Center of the Debate
For ID, the key issue is information: where does it come from? For naturalists, the answer is that regulatory networks and ecological dynamics are sufficient to account for it—even if the details remain incomplete.
Each side raises valid points, but the conversation often circles without resolution.
A Creation Model Perspective
A creation framework provides a broader synthesis. Like ID, it affirms the centrality of information. But it also incorporates geological evidence at the base of the Cambrian: erosional surfaces, tectonics, and analysis of fossil communities.
Below the boundary: mostly single-celled organisms. Above: multicellular animals, plants, and fungi.
Austin and Wise (1994) identified five markers of catastrophic change—erosional, tectonic, sedimentary, temporal, and paleontological—that align with the pre-Flood/Flood boundary. Taken together, the Cambrian explosion is not only a biological puzzle but also a geological watershed, suggestive of the same authors’ model of Catastrophic Plate Tectonics (CPT).^3
Seen this way, the sudden paleontological appearances and the massive restructuring of Earth’s crust are not coincidental but connected.
Why It Matters
The Cambrian debate reminds us that science and philosophy cannot be separated. Christians can affirm the reality of purpose and information while also recognizing God’s purposeful action in shaping both life and the Earth itself.
This is no “God of the gaps” but rather an integrated vision where geology, biology, and Scripture converge to reveal creation’s order and meaning.
Notes
- Marketa Kaucka, “Cis-Regulatory Landscapes in the Evolution and Development of the Mammalian Skull,” Philosophical Transactions of the Royal Society B: Biological Sciences 378, no. 1880 (2023): 20220079, https://doi.org/10.1098/rstb.2022.0079.
- Lucas Del Mouro et al., “A New Sponge from the Marjum Formation of Utah Documents the Cambrian Origin of the Hexactinellid Body Plan,” Royal Society Open Science 11, no. 1 (2024): 231845, https://doi.org/10.1098/rsos.231845.
- Steven A. Austin and Kurt P. Wise, “The Pre-Flood/Flood Boundary: As Defined in North America,” in Proceedings of the Third International Conference on Creationism, ed. Robert E. Walsh (Pittsburgh: Creation Science Fellowship, 1994), 37–47.
Want to explore these ideas further? Subscribe to our newsletter for weekly insights where faith and rigorous science converge.
About the Author: Dr. Neal Doran is a paleontologist and professor specializing in the intersection of creation science and the history and philosophy of science. He partners with theologian Jud Davis on the Biblical Theology Today podcast, exploring how Christians can engage science with both intellectual honesty and theological faithfulness.
Faith and Reason-25 