Darwinian Evolution | Plausible or Not? | The Cambrian Explosion

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The Solid Evidence

The fossil record, thought of as the greatest proof for Darwinian evolution by many has met its match. According to Darwin's theory, complex life should be followed by many intermediate or transitional forms in the materialization of fossils. One would hypothesize that the fossil record would show complex life forms evolving slowly as the creation of complex organs construct as a slideshow carved into the strata before our very eyes. There is a problem though, how can Darwin explain the cambrian explosion? Well it turns out he actually did have worries about it.
What is the Cambrian Explosion?

The Cambrian Explosion is what some call "The Big Bang of Biology" because of the rapid appearance of most of today's phylum (groupings of animals based on general body plans) that took place 541 million years ago. This means that in a geological blink of an eye (13-25 million years) complex organisms appeared without any trace of transitional ancestors besides bacteria which existed long before and possibly some sea creatures that were soft bodied. If fact, Dickinsonia (considered a soft bodied animal shortly before the cambrian explosion) is what most evolutionist believe to be our earliest ancestor as discoveries by the Australian National University show it did contain cholesterol. However, because not much is known about the composition and biochemistry of the extinct microbial plant phyla in the Ediacaran biota (635-543 Million Years Ago), we can not say just because it has cholesterol it was an animal. Evidence has shown that algae contains cholesterol, for example this paper by Govindan M. Furthermore, Dickinsonia and the few other soft bodied creatures that were found before the cambrian explosion cannot be ancestors to the complex creatures of that era. Precambrian fossils are still being debated, but there is no hard evidence to show that Dickinsonia had internal organs, eyes, anus, etc. Looking at the fossil record literally through an evolutionary perspective, it appears as if bacteria suddenly gave birth to hard bodied organisms with eyes, muscles, gills, mouths, and guts that were already equipped with most of the body plans we see today. 

Fossils before the Cambrian Explosion

Yorgia (555 Million Years Ago) was a disc shaped organism. It is currently classified in the extinct animal phylum Proarticulata. This animal phylum existed from 567-550 million years ago. Yorgia could reach a maximum length of 9.8 inches or 25 centimeters. 

Spriggina (550 Million Years Ago) was a organism that is often described as a worm like creature. Fossils of this creature have only been found in South Australia. Spriggina could grow up to 3 centimeters, and is now extinct.

Dickinsonia (567-550 Million Years Ago) was an oval shaped organism. It is not known exactly what this fossil was as it has been said to be a jellyfish, coral, mushroom, lichen, etc. Surprisingly it could grow up to 4.7 feet in length, but could only become a few millimeters thick. It lacks convincing evidence for a mouth, anus, and gut. It possibly could have fed by absorbing bacteria from the surface below. Dickinsonia has been assigned to the extinct animal group Petalonamae.

Charniodiscus (565-555 Million Years Ago) was a leaf shaped organism. It was probably a stationary filter feeder that may be considered as some form of underwater plant like animal life. For reference, this animal is usually compared to sea pens. Please see the video below for more information.

The life forms that were on Earth before the cambrian explosion seem to have been very plant-like. It appears as most life consisted of thin and squishy bottom dwellers that are now all extinct. Even though we have no proof of life still existing today from the precambrian era, we do from the cambrian. Sea pens actually date back to 508 million years ago (Middle Cambrian Era) as fossils have been found in Canada's Burgess Shale fossil deposit. 
The Cambrian Explosion Begins
541 million years ago an event jump started complex life on Earth. Before the early cambrian era (cambrian explosion) most of the phyla we see today did not exist. In a short (debated) period of around 13 to 25 million years, all complex phyla arose with no previous trace of transitional fossils. It is worth noting that some have claimed that the trilobite came from a precambrian ancestor, but that is widely accepted as not possible as of 2019. The parvancorina (1-2 cm) was thought of as a transitional form due to it's appearance of similarity, however in a paper by E.B. Naimark and Yu. Ivantsov the growth variability of this animal proved to be inconsistent with the arthropod phyla. This evidence, combined with suspected properties such as not being a self locomotive creature due to its size and similarity with temnoxa and kimberella (snail like molluscs).
Is 20 million years really a "short" amount of time?
We would say yes, as evidence from the coelacanth suggest so. The coelacanth was believed to have gone extinct 66 million years ago, and there is fossil evidence (Eoachtinistia foreyi) it could have existed up to 360 million years ago. The well preserved fossil above that is housed at Göteborgs Naturhistoriska Museum is around 150 million years old. Starting in 1938, coelacanth were found alive and continue to be found alive. They are considered a highly endangered species and usually live in caves 150-250 meters below the surface. The point is that they have not changed much at all and are nearly identical to their ancestors 150 million years ago. Generally, a small population can evolve faster and all evidence seems to suggest the coelacanth has not been doing so well as the fossil evidence suggested it went extinct 66 million years ago. After the discovery, it was stripped of its prize former role as a human ancestor.
From Simple to Complex
The fossils of phyla you see above are very similar to what we find alive in 2019. These are actually from a 518 million year old fossil rich site, the Qingjiang biota. This site dates back to the early cambrian and was discovered in 2019 close by the Danshui River in the Hubei province of China. So far, over 20,000 specimens have been found. A paper published in the journal science titled "The Qingjiang biota—A Burgess Shale–type fossil Lagerstätte from the early Cambrian of South China" describes that so far over 100 species have been identified, and about 50 are new to science. This site has also preserved soft body tissue in the fossils most likely due to the organisms being buried quickly. 
The vertebrae was also included in the cambrian explosion, and the Haikouichthy (seen above) is often used to show the earliest evidence for this dating back to around 525 million years ago. Following the Haikouichthy, Pikaia and Myllokunmingla also show support for vertebrates around this time frame (518-530 Million Years Ago). Pikaia actually has a look alike that is still living today called the branchiostoma (see below).

What we can see clearly is that advanced life was indeed an explosion, and we still never discussed the largest population of animals yet. During the explosion, trilobites roamed worldwide. The earliest trilobite fossil dates to around 530 million years ago, but because of the population size and the geologic location of these fossils the evidence seems that they had some extra time to multiply and fill the earth. These ocean animals were the most successful on the planet, not going extinct for 300 million years. The fossil evidence we have discussed above seems to indicate that hundreds of millions of years with both large (trilobite) and small (coelacanth) populations does not indicate any major evolutionary change within a specific animal. With over 15,000 described species over their 300+ million year existence (using survival adaptations) they hold our greatest record of diversification. What does this mean? In short, trilobites almost went extinct many times and were under tremendous evolutionary pressure and after all of that.. they were still trilobites. Here at Almighty, it is important to point out that we believe macroevolution (change in species, for example an ape like ancestor to a human) is impossible to the extent that it is mathematically so improbable that we just call it impossible. However, we do believe in adaptation or microevolution (small changes, for example a wolf into a dog). As long as a species can still reproduce with its similar ancestors we are okay with that because that's what evidence has shown. 

Critics 

A paper in the Biological Journal titled "The Cambrian evolutionary 'explosion': decoupling cladogenesis from morphological disparity" discusses phylogenetic evidence and states "Phylogenetic analysis proves the likelihood of ‘ghost’ lineages extending into the Precambrian". This is basically trying to discredit the explosion and tries to extend the trilobite origin date to as far back as 700+ million years ago. As you can tell the word "ghost" already explained their non existent evidence and shows how they can only speculate what happened with their assumption that Darwin's common ancestor model is correct. Basically the argument goes something like this: "Because these organisms appear radically with a hard body, guts, eyes, antennae, legs, muscles, and sensory organs this must mean they had a long time to evolve. The large population density and the spreading of the fossils we have also provides evidence that these organisms evolved a long time ago. We just don't have fossil evidence of the ancestors because they were only soft bodied." This makes up most of the arguments against the cambrian explosion. While it is true soft bodied organisms do not get preserved at a high rate due to the circumstances that must take place such as fast burial, this does not imply they existed before what the fossil evidence shows. Even in the precambrian era, we do find fossilized soft bodied creatures and to say that we couldn't find a single decently preserved soft bodied creature from earlier in the precambrian is absurd. As far back as 3.4 to 4.4 billion years (debated) we have fossil evidence of single celled life, Stromatolites. These are formed by cyanobacteria which obtain their energy via photosynthesis. Stromatolites are formed when cyanobacteria grow layer by layer on rock. The population of bacteria did fall over the billions of years, and some have tried to say that means animals must have been around to eat them. However, there is no evidence to support that and other alternatives can be brought up that are more probable such as environmental factors or the rise of protozoa. Protozoa are basically single celled organisms that are parasitic meaning they feed on organic matter. The population of bacteria peaked at 1.25 billion years ago and fell by 20% at the start of the cambrian era. Some hope for this to be evidence that animals existed over one billion years ago, but the decline could simply just be due to factors stated above or maybe even just the appearance of precambrian animals. Perhaps, the fall of some bacteria could have been a combination of factors. Last but not least, some argue that the evidence for life before the precambrian has been lost due to an unconformity in the rock layers (picture at top of article). However, unconformities are not world-wide in the sense they occur in the same place of the geologic time span. For example, the Grand Canyon has an unconformity (disturbance in geologic layers via plate tectonics or other factors) that made it lose information of the cambrian era. However, there is not an unconformity everywhere which allowed even strata from the Ediacaran era (about 635 million years ago) to be found. Time, once again thought to be evolutions greatest friend has met its match. Biologist like Stephen Blair Hedges declare that because life rose quickly on Earth that it could do the same elsewhere in the universe. However, clearly does not understand the complexity and sheer amounts of time evolution NEEDS as we discussed in our previous article detailing the chemistry behind organic molecules. The fact that complex bacteria arose so quickly following a very hostile and non-life sustaining environment shows need for a intelligent designer. The fossil record shows us that bacteria existed, then about 3.4 billion years later plant-like animal life and thin soft bodied creatures existed, then in a sudden blast of only 13-25 million years most major animal phyla we see today appeared with no clear evolutionary trace.

Conclusion

The complexity of the body plans and the diversification of the phyla we find appearing in the cambrian explosion can not come about via Darwinian processes in about 20 million years. What we literally see is single cellular life forming rapidly in a recently hostile environment, then it took about 3.4 billion years to evolve into simple soft bodied plant-like creatures, then in just around 20 million years evolution increased its rate of efficiency for an unknown reason and was more productive than ever. We should find more developed creatures in the precambrian era if life existed long before then, but we don't. What we do find is very simple creatures, possibly paving the way for what God had in store before his second great explosion.

We hope you enjoyed our 5th edition in our Evidence For God blog series! Check back every few weeks for a new topic.

 

 

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