Cambrian Explosion Was the Culmination of Cascading Causes, Evolutionists Claim.


Expanding underwater territory claimed as key to the Cambrian conundrum.

“Most of the hypotheses have at least a kernel of truth, but each is insufficient to have been the single cause of the Cambrian explosion,” says Oxford University’s Museum of Natural History paleontologist Paul Smith. Thus he sums up his conclusions about biological evolution’s “big bang,”1 the event his Durham University colleague David Harper says was “one of the most important events in the history of life on our planet.”

How do these evolutionists know an event they call the “Cambrian explosion” was so important? Because they cannot explain the abrupt “evolution” of diverse life forms all over the world at about the same time. And since they maintain these organisms were the evolutionary ancestors of all other animal life and ultimately even humans, they really need to explain how Cambrian life popped into the fossil record so suddenly.


Numerous evolutionary explanations have been suggested to explain the “Cambrian explosion” but none are adequate, according to evolutionary paleontologists Paul Smith and David Harper. Therefore, they conclude that massive flooding produced a spacious mineral-rich undersea environment where all of the inadequate explanations could work together to produce increasingly complex, larger forms of life. Image by M. Paul Smith and D. Harper, via Science.2

What It Is

Conventionally dated at about 541 to 515 million years ago, Cambrian rock contains an impressive collection of diverse life-forms without identifiable ancestral forms. Dominated by marine invertebrates, Cambrian rock also contains the deepest vertebrate fossils.

Therefore evolutionists ordinarily call it the “Cambrian explosion” to describe the inexplicably abrupt evolutionary appearance of such great worldwide biodiversity.

“This is a period of time that has attracted a lot of attention because it is when animals appear very abruptly in the fossil record, and in great diversity. Out of this event came nearly all of the major groups of animals that we recognise today,” Smith says. “Because it is such a major biological event, it has attracted much opinion and speculation about its cause.”

“It became apparent just how many hypotheses there were out there,” Harper says. “Thirty-plus over the past 10 years.”3 Despite the many hypotheses put forth to explain both the evolution of primordial life and its subsequent rapid diversification into increasingly complex life forms, evolutionists Smith and Harper found that all are inadequate. Yet because they are convinced that molecules-to-man evolution—however inexplicable—must have happened, they conclude that all the competing causes must have had a piece of the action. They say that the Cambrian explosion must have come from a “cascade of events.”

What It’s Not

After four years studying the Cambrian fossil record about 500 miles from the North Pole, Smith says, “Work at the Siriuspasset site in north Greenland has cemented our thinking that it wasn't a matter of saying one hypothesis is right and one is wrong. Rather than focusing on one single cause, we should be looking at the interaction of a number of different mechanisms,” he says. “What we need to do now is focus on the sequence of interconnected events and the way they related to each other—the initial geological triggers that led to the geochemical effects, followed by a range of biological processes.”

Though they write, “The rapid diversification of animals in the early Cambrian is likely to have been the result of a complex interplay of biotic and abiotic processes”4 in their article in the 20 September 2013 issue of Science, they do not address how non-living “abiotic” material could evolve into primordial life. They simply conclude that life must have evolved from non-life long ago and then progressed to become “the earliest members of many animal groups, including sponges, cnidarians, and bilaterians, [which] lived  850 million to 635 million years ago.”5 Why? Because life exists and therefore must have evolved from chemicals, and molecular clock calculations estimate it must have then progressed to a variety of simple ancestral forms on this timetable. Such molecular clock calculations6 are, however, likewise based on evolutionary presumptions, the presumption that, in essence, we are here, so molecules-to-man evolution must have happened.

Neither do they explain any observable mechanism by which so-called primitive organisms could then evolve into progressively more complex “higher” organisms. Instead, they propose that given a sufficiently large, well-lit, mineral-rich marine habitat, primitive life-forms must have, during “an apparent >100-million–year gap,” evolved countless evolutionary innovations and then assembled them into diverse complex organisms to fill the space.

The kickoff event for the Cambrian explosion . . . must have been massive worldwide flooding.

The kickoff event for the Cambrian explosion, Smith and Harper conclude, must have been massive worldwide flooding. “There’s a big kick that correlates with the sea level rise,”7 Smith says, referring to a previous study that suggested the Cambrian explosion was preceded by a rise in sea level. They maintain that minerals washed into the sea from land through erosion, supplying the chemical nutrients from which natural processes somehow built life. But key to the whole Cambrian conundrum, they claim, was the “increase in habitable area”8 under the sea. And since much of this water was shallow, they write, sunlight could penetrate to power the evolution of increased biodiversity.9

Smith and Harper propose that all other notions about the causes of the Cambrian explosion are correct for some corner of the world but that only the interaction of all the evolving organisms in evolving ecosystems could create the diversity of organisms preserved in Cambrian rock. In essence, Smith and Harper conclude that evolution isn’t just about time and chance; it’s about space, and given enough well-lit space, a world of competing complex animals evolved to fill it.

“It would be naïve to think that any one cause ignited this phenomenal explosion of animal life. Rather, a chain reaction involving a number of biological and geological drivers kicked into gear, escalating the planet's diversity during a relatively short interval of deep time,” Harper says. “The Cambrian Explosion set the scene for much of the subsequent marine life that built on cascading and nested feedback loops, linking the organisms and their environment, that first developed some 520 million years ago.”

Empty Answer

This creative solution to the Cambrian puzzle has the advantage of filling in the evident flaws in each and every evolutionary explanation by assuming that each one has a piece of the puzzle and that, when all the pieces are put together, the solution is assured. Thus this answer is no answer at all.

Biological research has never demonstrated that natural processes can convert non-living elements into living organisms. Nor have biologists ever observed simpler organisms evolve into more complex, new kinds of organisms. Smith and Harper ignore these deficiencies. Yet even assuming that evolution somehow overcame these glaring problems, their four years in northern Greenland revealed to them many other inadequacies in the various opinions proffered to explain Cambrian diversity.

Just as no numbers of millions of years are long enough to compensate for the lack of biological support for molecules-to-man evolution, so no amount of space under the sea is sufficient to show how a world full of life could bloom from lifelessness.

Order of the Rock Layers is Real

As seen in these illustrations from Answers magazine, the order in the fossil record is clue—not to a story of life’s evolutionary origins—but to many details about the historically documented global Flood. The Grand Staircase of the Colorado Plateau showcases many layers of sedimentary rock and the fossils preserved in them. Cambrian rock is the lowermost layer of the Paleozoic strata, which are indicated in yellow in the diagram. Notice in the accompanying chart the preponderance of shallow marine invertebrates that make their first appearance in the lowermost fossiliferous layers, followed by the first appearance of vertebrates just above them. Images: Answers magazine, A. Snelling, “Order in the Fossil Record.”

Fossil Patterns

When the abundance and diversity of Cambrian fossils are viewed without a predetermined commitment to unverifiable evolutionary presuppositions, however, another explanation for the billions of dead things buried in this fossil layer is apparent. Ironically, the historically documented explanation for the Cambrian explosion actually does involve water and flooding, but not chemicals-to-Cambrian life evolution.

“Ever learning, and never able to come to the knowledge of the truth.”

The “pre-Cambrian-rise-in-sea-level” study on which Smith and Harper based their conclusion, “Formation of the ‘Great Unconformity’ as a trigger for the Cambrian explosion,” was published in Nature in 2012 (doi:10.1038/nature10969). In it Shanan Peters and Robert Gaines proposed that the enormous discontinuity between fossil-rich Cambrian rock and the fossil-poor Pre-Cambrian rock below it resulted from a worldwide rise in sea level. This explanation, stripped of the millions of years, actually comes close to biblical truth. Most creationist geologists, understanding geology through the lens of biblical history, believe that Pre-Cambrian rock was pretty much in place prior to the global Flood of Noah’s day. Thus, Cambrian rock with its abundant marine fossils represents the first major sedimentary result of the biblical Flood.

Biblical history documents a global Flood, which lasted about a year, around 4,300 years ago. The Bible records that the Flood originated not just from rain but also from the opening of the “fountains of the great deep” (Genesis 7:11), an apparent reference to violent undersea activity. As the Floodwaters rose catastrophically, habitats and ecosystems would have been engulfed.  The first to be destroyed, churned, and dumped atop the “Precambrian” rock of the pre-Flood world would have been the seabeds, where upheavals would have suddenly buried countless undersea organisms. (See accompanying illustrations from Answers magazine, above.)

“The Cambrian fossilized creatures lived prolifically on the wide shallow sea floor surrounding the pre-Flood supercontinent,” Answers in Genesis creationist geologist Dr. Andrew Snelling explains. From the fossil record we can readily infer that “they were picked up and buried by the rising violent ocean waters as they swept up onto the broken up continental fragments.” Thus shallow marine invertebrates form the dominant population of Cambrian rock, the first sedimentary layer laid down by the global Flood. Subsequent burials of organisms as the waters rose higher would have created layer after layer of sedimentary rock, creating much of the fossil record, not over millions of years, but early in the Flood year.

Biblical history thus supplies the answers that countless cascading evolutionary events cannot. Read more about the order in the fossil record and how it is consistent with the global Flood at Order in the Fossil Record and The New Answers Book 2, Doesn’t the Order of Fossils in the Rock Record Favor Long Ages?.

Further Reading

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Answers in Depth

2013 Volume 8


  1. Carl Zimmer, “New Approach to Explaining Evolution’s Big Bang,” The New York Times, September 19, 2013,
  2. M. Paul Smith and D. Harper, via “Causes of the Cambrian Explosion,” Science, September 20, 2013: 1355–1356, doi:10.1126/science.1239450.
  3. Zimmer, “New Approach to Explaining Evolution’s Big Bang.”
  4. Smith and Harper, “Causes of the Cambrian Explosion.”
  5. Ibid.
  6. Molecular clock dating assumes that mutation rates over great spans of time can be known and remain constant. The method is based on foundational data that suffers from the statistical mismanagement of error ranges as well as the assumption that one kind of creature in the fossil record evolved into another by accumulating mutations. And circular reasoning is inherent in the calibration of the “clocks” in accord with the radiometric dating methods, giving the appearance of “confirmed” interpretations. For more information see Elizabeth Mitchell, “Researchers Devise Alternate Theory For Cambrian Explosion,” Answers in Genesis, December 3, 2011,; and Elizabeth Mitchell, “News to Note, December 31, 2011: Year in Review,” Answers in Genesis, Decemeber 31, 2011, "
  7. Zimmer, “New Approach to Explaining Evolution’s Big Bang.”
  8. Smith and Harper, “Causes of the Cambrian Explosion.”
  9. Ibid.


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