Today’s New Reason To Believe

Posted by Fazale ‘Fuz’ Rana, Ph.D.

New Understanding of Precambrian Fossil Tracks Makes Biology’s Big Bang More Explosive

I have three teenage daughters. They are good kids, but—as all teenagers are apt to do—they occasionally try to get by with things they shouldn’t. Usually when my wife or I suspect that something is amiss, my daughters will try to talk their way out of it by coming up with a story to defuse our suspicions. Still, it’s usually pretty easy to figure out that things are not on the up and up when all the facts don’t match their explanation.

This is also the case when it comes to the theory of biological evolution. Evolutionary biologists have constructed reasonably plausible scenarios to account for life’s origin and history through strictly mechanistic natural processes. But the facts don’t always match their explanations. The chief example of this is the Cambrian explosion. (For some articles on the problems that this dramatic event in life history creates for the evolutionary paradigm, go here, here, here, and here.)

Known in Darwin’s time, the Cambrian explosion refers to the dramatic appearance of complex animal life in the fossil record about 540 million years ago. Within a short period of time—perhaps less than 5 million years—anywhere from 50 to 80 percent of all animal phyla to ever exist on Earth appeared. The animals that came into existence during the Cambrian explosion were marine creatures. Instead of relatively simple organisms originating at the base of the Cambrian and then evolving toward increased intricacy, complex animals appear suddenly. The traditional evolutionary explanation argues that life should transition from simple to complex in a gradual, branching, tree-like fashion. On the other hand, such explosive appearances are exactly what should be expected if a Creator is responsible for orchestrating life’s history.

Like guilty teenagers confronted with evidence that exposes their explanation, evolutionary biologists try to change their story. This has surely been the case with regard to the Cambrian explosion, as scientists have tried to come up with alternative scenarios to explain away the devastating implications of the Cambrian event for the evolutionary model.

New work published in the journal Current Biology, however, eliminates one of the best counterexplanations that evolutionary biologists have mustered for the Cambrian explosion, making it even less likely that the facts surrounding “biology’s big bang” can be explained away.

The Cambrian Explosion and Darwin

When Darwin wrote On the Origin of Species, he was careful to acknowledge problems with his theory. One of those problems centered on the Cambrian explosion. Darwin wrote:

There is another and allied difficulty, which is much more serious. I allude to the manner in which species belonging to several of the main divisions of the animal kingdom suddenly appear in the lowest known fossiliferous rocks… To the question why we do not find rich fossiliferous deposits belonging to these assumed earliest periods prior to the Cambrian system, I can give no satisfactory answer.

Darwin was referring to the fact that geologists of his time recognized that no fossils of complex animal forms existed in rock formations older than 545 million years. Yet, rocks from the Cambrian time frame (545-485 million years ago) are replete with such remains.

He sidestepped this problem by arguing that the fossil record was incomplete and poorly studied. He expected that as paleontologists collected and analyzed fossils over time, the missing transitional forms and gradual evolutionary transformations would be uncovered. Over the last 150 years, paleontologists have indeed uncovered a treasure trove of fossils that document a rich history of life on Earth.

A Brief Description of Life’s History

The fossil record indicates that prior to about 570 million years ago life on Earth appears to have been dominated by single-celled organisms. At that point an event known as the Avalon Explosion took place. During this origins event, an enigmatic fauna of complex marine creatures known as the Ediacarans appeared. The Ediacaran fauna consisted of about 270 species that have been recovered as fossils in about thirty localities around the world. The organisms disappeared shortly before the Cambrian explosion. New research indicates that Ediacaran fauna emerged explosively, in the same manner as that of the Cambrian event.* During the Avalon explosion the full range of anatomical characteristics displayed by the Ediacarans was already expressed around 570 million years ago. In other words, no evolutionary buildup of biodiversity.

While some of the Ediacaran organisms persist into the Cambrian and a few may have connections to organisms that appear in the Cambrian explosion, most do not. For the most part, the Ediacaran fauna disappears right before the Cambrian explosion.

After the Ediacaran organisms became extinct, the Cambrian explosion took place and represents the first appearance of animal life as we know it today. The last century-and-a-half of research into the fossil record has failed to uncover the missing fossils that Darwin lamented.

A Possible Loop-Hole

While some paleontologists agree that the Cambrian explosion is a real, but enigmatic event—at least enigmatic from an evolutionary vantage point—others argue along Darwin’s famous line. They maintain that the Cambrian explosion is an artifact of an incomplete fossil record. In other words, there is a vast evolutionary history that is invisible because the first, simplest multicellular life-forms weren’t preserved in the fossil record.

To support this appeal to the fossil record’s incompleteness, evolutionary biologists point to trace fossils found in rocks as old as 2.1 billion years in age.

These fossils have been interpreted as tracks produced by complex multicellular animals that were the evolutionary precursors to the organisms that emerged in the Cambrian explosion. These trace fossils are typically characterized as a sinuous groove cut into the ground with a central ridge. The groove is bounded by two lateral ridges. Presumably, these traces were produced by an animal capable of movement that possessed bilateral symmetry

A Surprising New Insight about Trace Fossils

This interpretation, though reasonable, doesn’t appear to be correct based on recent work done by a team of oceanographers and biologists. These scientists were diving near the Little San Salvador Island of the Bahamas and noticed tracks on the ocean floor that were identical to the trace fossils ascribed to the movements of ancient complex animal life thought to have lived well before the Cambrian explosion.

To their surprise, the tracks looked as if they were produced by a large single-celled creature called Gromia sphaerica. The researchers surmised that the tracks resulted from the rolling movement of this organism.

Implications

This find means that the trace fossils in ancient rock formations older than 540 million years were likely not created by complex, multicellular animals, but instead by single-celled organisms like G. sphaerica. This discovery eliminates one of the most compelling counter-explanations that evolutionary biologists give for the validity of the Cambrian explosion. In spite of evolutionary biologists’ story, it looks like the best way to account for the facts associated with the origin of animal life is through the work of a Creator.

*For a discussion of the latest insights into the Avalon explosion see the booklet 10 Breakthroughs of 2008

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Punctuated equilibrium doesn’t have a viable mechanism

This past Thanksgiving, my family and I (along with some good friends) rode down to the bottom of the Grand Canyon on mules. That night we ate dinner at the Phantom Ranch and the next day rode back out of the canyon. It was an amazing experience to be immersed in God’s creation—but also terrifying at times to be on the back of a mule maneuvering on rugged and narrow trails overlooking sheer drops of hundreds of feet. I was sure thankful my mule (Tin Man) had a good sense of equilibrium. If he didn’t, it would have been all over for both of us on a few occasions.

The evolutionary paradigm also depends on equilibrium (of sorts). Many paleontologists assert that biological evolution occurs by a non-Darwinian mechanism referred to as punctuated equilibrium. According to this view, biological evolution occurs rapidly—in spurts—followed by long periods of stasis.

Proponents of punctuated equilibrium posit that evolution only occurs when a small subpopulation of a species becomes isolated from the general population. If the isolated subpopulation becomes confined to the periphery of the species’ normal geophysical range, evolution will occur rapidly, say evolutionists, if the environmental and predatory pressures found in the periphery differ significantly from those found in the species’ typical geographical range. Experiencing different conditions, the peripheral subpopulation is not ideally suited for its environment. This mismatch provides the driving force for evolutionary change. When occupying its normal range, natural selection prevents a species well-suited for its environment from evolving. In other words, natural selection promotes stasis.

Punctuated equilibrium seems to explain the fossil record. If a new species emerges rapidly from a small peripheral subpopulation, it will seem as if that new species appears suddenly in the fossil record, and few if any transitional intermediates would be expected.

Even though punctuated equilibrium can explain the troubling features of the fossil record, one key question remains. Does the mechanism undergirding punctuated equilibrium actually work? Research results published in 2001 indicated, no.

Theoretical work by University of Oregon scientists shows that the essential processes making up punctuated equilibrium’s mechanism lead to extinction, not evolution. These scientists demonstrated that risk of extinction significantly increases for a species when its population becomes disconnected. Moreover, environmental changes and habitat fragmentation exacerbate a disconnected population’s susceptibility to extinction. Population and habitat fragmentation, along with an altered environment, stand at the center of punctuated equilibrium’s mechanism.

Investigators from Washington University in St. Louis produced field work confirming the work done by the scientists from the University of Oregon. Studying collared lizards in the Missouri Ozarks, the Washington University scientists showed that habitat fragmentation doesn’t drive speciation; rather it leads to extinction.

These two studies create a serious problem for the evolutionary paradigm. As discussed last week, strict Darwinian evolution lacks the necessary corroboration from the fossil record and cannot be declared a fact. Punctuated equilibrium “explains” the fossil record, yet fails due to the absence of a legitimate mechanism and must be rejected as an explanation for life’s history.

Though many evolutionary biologists would claim that I am off-balance, it seems to me that the absence of any conceivable naturalistic explanation for the origin and natural history of life’s major groups opens the possibility for the work of a Creator.

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Fossil evidence reveals that evolutionary change is seldom directional.

As a parent, one of my biggest concerns is that my children have a direction for their lives. I don’t want them to waste time aimlessly going through life.

Unfortunately for the evolutionary paradigm, new research indicates that the fossil record has lost its direction. But this loss of direction isn’t bad for a different paradigm. This new insight adds to the evidence indicating that life’s history has a purpose orchestrated by a Creator.

One of the key pieces of evidence cited in support of biological evolution is the fossil record. Evolutionary biologists point out that: 1) the fossil record shows that past life on Earth is different than life today; and 2) simple life preceded complex life-forms. For many scientists these general features indicate that life on Earth must have evolved.

These observations, however, could just as easily be accounted for by evoking the work of a Creator who created in stages, bringing different life-forms into existence at different times in Earth’s history. This pattern accords with the Genesis 1 and Psalm 104 creation accounts.

What about the specific features of the fossil record? Can these patterns find explanation within a creation model context? Or are they best understood within an evolutionary framework?

Given a Darwinian mechanism, it’s expected that the fossil record should display gradual transformations replete with corresponding transitional forms. Over the last 30 years or so paleontologists have debated whether or not the fossil record truly displays this pattern. In the early 1970s, Stephen Jay Gould and Niles Eldredge argued that the fossil record fails to show gradual evolutionary transformations. Instead these two paleontologists maintained that evolutionary change happens suddenly and then periods of stasis, or no evolutionary change, follow. They termed this idea punctuated equilibrium.

Ironically, the pattern proposed by Gould and Eldredge—punctuated equilibrium—is consistent with the work of a Creator and matches the pattern for the fossil record predicted by the RTB creation model. Since its proposal, punctuated equilibrium has been a controversial idea, provoking much debate among scientists about the actual patterns observed in the fossil record.

A recent study published in the Proceedings of the National Academy of Sciences addresses this controversy. The researcher conducting the study examined 250 documented cases in which biological traits were monitored in fossil lineages, statistically assessing the percentage of 1) directional change; 2) random walk; and 3) stasis. He noted that only 5% of the fossil lineages showed directional change while roughly 45% displayed random walks and about 45% stasis. (The 5% of cases displaying directional change most likely represents an overestimate due to a selection effect. Paleontologists are more likely to study fossil lineages that show change than those remaining static.)

In addition to these overarching trends, the statistical analysis also uncovered specific patterns. It turns out that stasis is much more prominent for features related to shape. In contrast, directional trends are more likely to involve changes in body size. Likewise, planktonic microfossils (visible under a microscope) showed a more pronounced tendency to experience directional changes than macroscopic (visible to the naked eye) fossil lineages. More often than not, macroscopic forms displayed stasis.

The statistical analysis supports the central claim of punctuated equilibrium and indicates that directional change in fossil lineages is quite limited.

The patterns uncovered by the study are also consistent with a Creator’s work in life’s history. Organisms created in an optimal state would be expected to experience stasis because virtually any change would cause them to lose fitness. Random walks observed in the fossil lineage could be interpreted as genetic drift and the few cases of directional change are consistent with microevolutionary changes in organismal size or evolutionary advance of microscopic creatures with large population sizes.

The patterns uncovered by this study are provocative in light of the analysis of life’s history conducted by biologist Eugene Koonin, discussed previously. Koonin demonstrated that life’s history is best described as a sequence of biological big bangs with little, if any, evidence for intermediate forms.

Still, can punctuated equilibrium account for the patterns observed in the fossil record without evoking the Creator’s hand?

I will discuss this question next week.