By Charles L. Rulon
Emeritus, Life Sciences
Long Beach City College
The Cambrian Period
The Cambrian is an ancient period in geological time that lasted from 542 million years ago (mya) to 490 mya. It is the earliest time in geological history that plant and animal fossils appear in abundance. During the Cambrian a menagerie of multicellular life “exploded”, including fossils of algae, sponges, worms, mollusks (animals with shells), arthropods, and ancient jawless fish. It appears that nature had begun to experiment with a rich variety of fundamentally different body designs, several of which served as rough blueprints for all to come. The beginnings of most of today’s major animal body types are first seen as fossils in the Cambrian.[i]
The Cambrian and Creationism
Creationists love the Cambrian “explosion”. To them, it proves that all the major types of animals (phyla) suddenly materialized, being instantly created by God. In the early 1970s I debated Dr. Duane Gish from the Institute for Creation Research near San Diego California.[ii] Even though Dr. Gish had a Ph.D. in biochemistry, he had turned his back on the scientific method in favor of sham science supporting the young-earth Genesis creation story.[iii] The debate was held at Long Beach City College in front of a large audience made up of students from science classes and creationist Christians, mostly bussed in from the community.
Dr. Gish told the audience that the earliest known fossils appeared suddenly with an explosive abundance in the Cambrian rock strata and that they were already highly complex forms of life representing all the major phyla. “One minute, no phyla; the next minute 38 phyla, the same number as today.” The conclusion, said Gish, was inescapable. Instead of evolution, the fossil record supports the sudden creation of all major life forms.[iv]
However, the scientific reality is quite different:
a. In stark contrast to the teachings of the Institute for Creation Research, the “Cambrian Explosion” didn’t take place in a few days some 6000 years ago, as required by a literal reading of Genesis-1. Instead it took place over a period of at least 15 million years from roughly 525 to 510 million years ago.
b. The number of different phyla identified in the Cambrian is not 38, as Gish asserted; it is a highly variable number, subject to fallible human interpretations of fossilized remains. Many of these early body types are only found in the Cambrian. Furthermore, while almost all of the now living marine phyla were present, most were represented by classes that have since gone extinct. Cambrian echinoderms were strange-looking, not our familiar starfish, sea urchins and brittle stars. Also, there were no bony fish, amphibians, reptiles, birds, or mammals found in the Cambrian. Bony fish first appear about 80 million years later, reptiles about 200 million years later and mammals some 300 million years later. There are also no insects, ferns, conifers, or flowering plants found in the Cambrian. Thus, the creation picture Gish painted was extremely misleading.
c. One possible explanation for this apparent “explosion” of diverse life forms in the Cambrian is that for the first time hard shells, tubes, scales, spines and carapaces had evolved. Calcified structures can leave excellent fossils compared to soft-bodied animals, which leave poor or no fossils. Dr. Gish rejected this possibility.
d. Finally, and contrary to Gish’s creation model, but of critical relevance, the Cambrian fossils are not the earliest fossils of animals discovered. Millions of years earlier there were the Ediacaran fauna, the first animal-like organisms to be fossilized. Some look like sponges, some are a bit like jelly-fish, some like sea anemones, and others like worms. Also, there are pre-Cambrian fossil imprints of tracks and burrows. In his presentation, Gish simply dismissed all of these earlier fossils as unproven speculation by desperate evolutionists.
“God did it” is bad theology
Theologians have come to realized that it’s bad theology to rely on “God did it” answers for scientific unknowns, since one’s faith is now potentially at risk if science can fill in these gaps. This risk is quite high given that scientists have been extremely successful over the last few centuries in replacing “God did it” answers with naturalistic explanations.
The Cambrian Explosion is one such example. Since my debate with Gish almost 40 years ago, there has been the discovery of several new Cambrian fossil beds. There has also been the development of new high-tech fossil discovery tools and molecular clock dating techniques. These tools and techniques have resulted in the discovery of more and more pre-Cambrian fossils.
As one example, some fossilized microscopic ancestors of all the bilateral animals have been found in the Doushanto formation in China, which dates to some 50 million years before the Cambrian.[v] Also, there is now evidence that several of the phyla found in the Cambrian go back much earlier, with ancestors spread out over hundreds of millions of years in the pre-Cambrian.[vi]
Yet, almost 40 years after I debated Dr. Gish, the Cambrian is still being used as evidence for “intelligent design,” the Trojan Horse of creationism.[vii]
[i]There are at least 30 different locations where ancient Cambrian rocks are exposed. At three of these locations fossil beds have been discovered where freak conditions amazingly preserved soft body parts as well as shells, spines and carapaces. These three locations are the Burgess Shale of British Columbia (discovered in 1909), Sirius Passet of northern Greenland (1984), and the Chengjang site of southern China (1984).
[ii] The Institute for Creation Research (ICR) is one nerve center for the young-earth creationists’ movement. For five decades it has presented an instantaneous creation model, which it claims is a scientific alternative to evolution. This model matches a literal reading of Genesis 1. Outdated references, purposeful misquotes, illogical arguments and half-truths dominate.
[iii]Sham science is selectively picking out data which appear to support what believers already know to be true, while ignoring, distorting and explaining away data which conflict with their beliefs.
[iv]See Gish, D. 1978 (1985), Evolution, The Fossils Say No! Creation Life Publishers.
[v] Why Intelligent Design Fails, 2004, by Mark Young and Taner Edis (Editors): A devastating critique of all of the scientific claims put fourth by the ID/creationist movement.
[vi] Dawkins, The Ancestor’s Tale, 2004. Also visit
[vii] Stephen Meyer, director of the Center for Science and Culture (