Cambrian Explosion, No Help to I.D.—Agassiz trumps Darwin? (Stephen C. Meyer, Signature in the Cell, Darwin's Doubt, Louis Agassiz, Discovery Institute, Intelligent Design)

Cambrian Explosion

The Cambrian Explosion, No Help To I.D.

How different were organisms from one another in the pre-Cambrian?

Viewing the organisms of each phyla at the beginning of the Cambrian “explosion” it looks like bilaterian worms had been radiating into more complex and diverse worms (and early slug-like organisms had been radiating into more complex and diverse invertebrates), because in general the earliest Cambrian relatives of the living phyla tend to be a lot more wormlike (or sluglike in the case of invertebrate phyla) than most modern day representatives of such phyla. Even many living phyla are basically still worms (or slugs). In short, early representatives or relatives of the chordates are rather more wormlike than their better–known modern representatives.

In the Cambrian the earliest members of the “chordate” phylum (out of which humans eventually evolved) resembled filter–feeding worms that happened to swim. They didnʼt have jaws, scales, a bony skeleton, or anything else that most readers would even associate with a “fish!” They looked like the first two pics on the right:

And the process of their development from the Cambrian onward, before they had evolved jaws, included nothing but rounded sucking mouths. See the third and fourth pics down on the right:

What about those trilobites you ask, i.e., animals with hinged exo-skeletons, the cousins to modern day crabs and insects? Didn't they burst onto the scene in the Cambrian seemingly from nowhere? Their appearance was preceded by millions to tens of millions of years of small shelly fossils (see pic down on right), which provides evidence of evolution and diversification of hinged exo-skeleton organisms prior to the Trilobite deposits in the Cambrian. The small shelly fossils in Chenjiang feature dozens and dozens of trilobite–like and arthropod–like organisms that preceded the Cambrian "explosion," but which fall cladistically outside of these respective clades—these are transitional forms! How can Meyer have ignored the plain evidence that the Cambrian “explosion” did not come out of nowhere?

Additional evidence that Meyer brushes aside supports the view that pre-Cambrian organisms developed in stages, from single–celled organisms up to the worms, slugs and little shellies that preceded the Cambrian Explosion:

The Sequence of Fossils in the Pre-Cambrian Appears Evolution-Like

  1. Before 700 million years ago, maybe well before: Single–celled eukaryotes (acritarchs), which are not to be confused with the smaller simpler prokayotes (bacteria) for which we have some very rare and early fossil evidence.

  2. Earlier Ediacaran: Multicellular animal eukaryotes, but simple, SPONGE–grade organisms (Sponges consist of communities of single–celled eukaryotes, and a sponge run through a sieve that disconnects all of its cells can re–assemble into a sponge again).

  3. Later Ediacaran: Multicellular animal eukaryotes with more complexity, i.e. cnidarian–grade organisms

  4. Very late Ediacaran: Simple SLUG–grade/WORM–grade organisms (at least their tracks and burrows) – the first ones only making surface tracks and lacking burrowing ability. Making tracks suggests that the organisms have at least a front end and a back end, a mouth, anus, and gut connecting them. These are almost certainly bilaterians.

  5. Very late Ediacaran: The very first biomineralized “skeletons”, e.g. Cloudina, basically a WORM secreting a tube, as well as the first evidence of predatory boring. Cloudina gets no mention at all in Meyerʼs book.

  6. At the beginning of the Cambrian, we start to see more complex burrowing – e.g., vertical burrowing through sediment, clearly indicating WORM–grade organization and an internal fluid skeleton, i.e. a coelom. The burrows gradually increase in complexity over 10 million years.

  7. SMALL SHELLY fauna: The shells, which started very small and very simple, gradually diversify and get more complex, radiating especially in the Tommotian. By the end of the Tommotion, some of the “small shellies” can be identified as parts of larger, “classic” Cambrian animals. The Tommotian is an utterly key period for any serious discussion of the Cambrian explosion. Unfortunately, the word “Tommotian”, or any equivalent terminology does not even appear in the book! The Small Shelly Fauna (SSF) gets just one (one!) mention in the book, buried in endnote 27 of Chapter 4.)

All of the above evolution-like stages of increasing complexity preceded the Cambrian "explosion."

from before the “Cambrian explosion”

Questions For I.D. Regarding the Known Phyla

Maybe an I.D.ist can explain why we need 33–40 phyla when merely 9 of those phyla constitute about 95% of all animal life? The remaining 26–31 phyla have fewer than about 2,000 known members—the rarest with just three members (Cycliophora: odd sacs represented by Symbion pandora), two members (Xenoturbellida: strange flatworm) or one species (Micrognathozoa: tiny jawed animal, and Placozoa, an animal that resembles a multicellular amoeba). Most are simple marine organisms, often referred to as worms or nanoplankton.

Also, how about an I.D.ist explaining why, among multi–cellular organisms, beetles and mites proliferate so much, producing hundreds of thousands of species, while other phyla produce far fewer? The number of species of mites might even reach 1 million according to some estimates, as more beetles and mites continue being discovered all the time. Wow, the Designer or Natureʼs innate design abilities really seem focused on mites.

ALSO…

13 phyla of multi–cellular animals appear during the Cambrian explosion.

BUT…

20 phyla of multi–cellular animals appear AFTER the Cambrian. Neither is the number of phyla into which all the worldʼs species can be divided agreed upon among systematicists. Under the most frequently used classification scheme there are 38 animal phyla, but some systematicists claim there are between 35 and 40 phyla. Three new phyla were discovered in the last century, the most recent in 1993.

Meyerʼs Creationist Hero, Louis Agassiz

Meyer idolizes Agassiz, a creationist who opposed even the evolutionary idea of common descent. Here is how Agassiz argued for creationism in his day [SOURCE: Agassiz, Evolution and Permanence of Type, The Atlantic Monthly, 1874, pages 92–101]:

“…the earliest known Vertebrates” [from the fossil record when Agassiz was writing] “…are Selachians (sharks and their allies) and Ganoids (garpikes and the like), the highest of all living fishes, structurally speaking.”

“It shall be answered that these belong to the Silurian and Devonian periods, and that it is believed [by evolutionists] that Vertebrates may have existed before that time. It will also be argued that Myzonts, namely Amphioxus, Myxinoids [Hagfish], and Lamper–eels [Lampreys], have no hard parts and could not have been preserved on that account. I will grant both these points, though the fact is that the Myzonts do possess solid parts, in the jaws, as capable of preservation as any bone, and that these solid parts, if ever found, even singly, would be as significant, for a zoologist, as the whole skeleton.”

In other words Agassiz was mocking evolutionists for not finding fossil evidence of the earliest jawless eel–like vertebrates in the fossil record prior to the Devonian. He was also mocking them for not finding fossil evidence of Amphioxus (or Amphioxus–like organisms) with a mere notochord and eyespot that existed prior to jawless eel–like vertebrates in the fossil record.But fossil evidence of both have since been found, and they were found in the places where the Evolutionists expected them to be found.

Agassiz also wrote loads that argued in favor of the idea that different races of humanity were each created separately and could be classified on the basis of specific climatic zones (just as he viewed the separate creations of animal and plant species), and that the different races of humanity were accordingly endowed with unequal attributes by their Creator. Nor was it unusual for Agassiz to have been a zealous defender of creationism since he came from a line of ministers, and during his natural science studies he favored Cuvier the creationist over Lamarck the transformationalist/evolutionist.

Meyer Admitted that the Lack of Abundant Fossils Prior to the Cambrian Cannot be Cited as Good Evidence in Favor of I.D.

A specialist in the Cambrian debated Meyer on a radio program and pointed out to Meyer the development of various organisms before the Cambrian explosion as seen in “little shellies” formations. After which Meyer backed away from the idea that the lack of abundant fossils prior to the Cambrian explosion provided evidence for I.D. Instead, Meyer admitted that enough pre–Cambrian fossils existed to provide evidence of changes in organisms occurring prior to the Cambrian.

Meyer should also be embarrassed concerning how closely his charts of the major phyla resemble the charts creationists used in the 1980s when they tried to argue that each phyla was created independently. He should have used more detailed charts such as these.

Meyer also needs to consider that species have to spread widely in order to increase their chances of even being fossilized. Some species are going to be far more successful at reproducing and invading new environments and they are going to spread widely and have a much greater chance of being fossilized. While branches of those species, their “cousins” so to speak, may go extinct far sooner, with little chance of the remains of such extinct cousins being fossilized at all. To suggest an analogy, the fossil record resembles a car park garage buried sometimes slowly, and sometimes by a catastrophe (thatʼs what todayʼs geologists believe about the fossil record, their view is called Actualism, which leaves room for both Uniformitarianism and local Catastrophic burying events). There are cars on each level of the parking garage, but the cars undergoing transitions are on the ramps between levels and havenʼt reached the point where their descendants cover a large part of any one level of the car park garage yet. So when the garage is buried the cars on the ramps are naturally less numerous. (And many of those side ramps simply lead off a cliff, leaving little to no remains, i.e., all those cousin species that go extinct for each species that makes it to a different level of the car park garage and expands its brood there, and increases its chances of leaving fossils behind. If you donʼt know where to look for the ramps, your odds of finding transitional fossils are minimal.

Paleontologists dig up transitional fossils by traveling to exactly those places on earth where the strata is dated to the time period where such transitions most likely existed, and finding an outcropping there that is exposed and that is also known to contain fossils. That is exactly how the discovery of the first mammal–like reptile fossil was made. Some brave paleontolgists traveled way up north to a particular outcropping that was dated to a particular time period between reptiles and mammals and known to contain fossils, and they found the first mammal–like reptile fossils (with double–jaw joints and other transitional features). Some of those intrepid paleontologists also died as a result of the harsh weather they experienced during their digs up there. A more recent case was the discovery of the amphibian–like fish, Tiktaalik. The paleontologist leader of the expedition knew the geologic record and where such transitions would had taken place and obtained funding to visit particular strata from that period that was exposed and known to be fossiliferous. In other words they trekked to the “ramp of the parking garage” and found on that ramp the remains of Tiktaalik, a fish with an amphibian–like skull, eyes on the top, a distinct neck, finger bones, and other amphibian–like characteristics, but in a fish. They also got lucky in that it was near the time when they would have had to retreat because winter was coming and the ground was beginning to refreeze and would have remained frozen most of the year too.

Does Meyer mention how important it is to look in the right places, geologically speaking, for transitional fossils? Does he mention that that is exactly how transitional species have been successfully discovered? Does he mention that the “Pre–Cambrian” is not really a geologic period at all due to the enormous upheavals that took place during that period? Itʼs simply rock that has no name for a period all its own, other than being “pre”Cambrian, like a heavily erased black board that you hope to discover some scribbles on that nature has not yet erased.

Also, paleontologists realized after more fossils of each species were discovered that if there was a “design” to the way organisms continued to change and spread out on the earth, that design was not straightforward. It began to look more like nature was trying everything, experimenting, trial and error–wise, tinkering, and failing a huge amount of the time. The discovery of an increasing number of ancient horse–like species led to them co–existing at different intervals and most dying out like leaves on a bushy tree when autumn comes, not following a straight path that might imply an intended plan of “design.” The fact that most species simply go extinct doesnʼt exactly cry out “intelligent design.” Vast numbers of cousin species simply go extinct, often leaving behind Nothing But A Wide Diversity Of Teeth (enamel is one of the hardest of natural substances). Meyer in his book mentions such things as the Permian extinction, which was the largest known mass extinction event. Was the Designer shaking his etch–i–sketch?

I read that the most complete T. Rex is only about 85%. Most evidence for T. Rex was quite fragmentary until that special fossil was finally found. The same is true of fossils of other species from horses to hominids to cetacea. Often only the teeth have survived and been discovered that bear silent witness to the existence of endless cousin species that once existed but exist no more. To quote Carl Zimmer in his book At the Waterʼs Edge, on cetacean evolution and the fossils of ancient cetaceans that we possess:

“Itʼs tempting to build this story like a totem pole, with trotting Pakicetus at the base, Ambulocetus laying its humming jaw on top of it, and Rodhocetus, the earliest whale to swim like a whale, sitting above the two. It seems like such a smooth progression toward todayʼs cetaceans that it must be right. But such a version would only be a vertical slice of the story. Life doesnʼt proceed from one point to another — it forks and radiates like the cladograms that represent it. Paleontologists have found many other whale bones in Eocene rocks of Pakistan and India. Mostly They Are Teeth — the rock surrenders A Few skulls as well — but even teeth clearly show that their owners were Not Clones of Pakicetus or the other better–known whales. Ambulocetus kept to brackish deltas and coastal water, but Thewissen has found whale teeth from about the same age in what at the time was the open ocean. Gingerich has found at least three contemporaries of Rodhocetus a few million years younger than Ambulocetus: Takracetus, with a wide, flat head; Gavinocetus, with a slender skull and loose hips; and Dalanistes, a whale with a head as long and narrows as a heronʼs set on a long neck, with hips cemented firmly enough to its spine to walk on land. If this is a confusing picture, it should be. As time passed, certain whale species emerged that were more and more adapted to life in the water, but other species simultaneously branched away in many directions. Walking and swimming whales lived side by side, or in some cases traded homes as the buckling birth of the Himalayas shuffled their habitats. Some were only a minor variation on a theme that would carry through to modern whales, but others — heron–headed Dalamistes, for example — belonged to strange branches unlike anything alive today.”

As I said concerning the parking garage analogy, tons of cousin species went extinct, and species that had not succeeded to the point of spreading far and wide have far less chance of being fossilized.

The Impatience of Intelligent Design Advocates

If I.D. is the assertion that some unknown intelligence used unknown means to instantaneously create biological structures then any discussion of I.D. will be relatively short and unsatisfying. Behe explained his view as “A puff of smoke!” A suspension of the laws of physics. Not very satisfying as a scientific answer. [Google this search string: Behe and puff of smoke] And the I.D.ist Berlinski wrote: “Before the Cambrian era, a brief 600 million years ago, very little is inscribed in the fossil record; but then, signaled by what I imagine as a spectral puff of smoke and a deafening ta–da!, an astonishing number of novel biological structures come into creation, and they come into creation at once.” Berlinski added the word “ta–da.” Of course Berlinski also seems ignorant of the “little shellies” in the pre–Cambrian, as well as the fact that early Cambrian phyla resemble variants of worms and slugs with far more “novel” species and biological structures coming into existence over geological time.

More to the point is how did “intelligence” do it? Via what stages and via what particular acts of intervention was each change in biological structures accomplished? Did the “Designer” utilize chemicals that already exist inside each cell, chemicals that naturally induce mutations, and move them telekinetically toward the right spots in the DNA chain to effect this or that point mutation? Or did the Designer effect a "whole genome duplication" event in some cases and whittle things down from there? Did God bend and focus mutation–causing cosmic rays so that they penetrated the nucleus of a particular egg or sperm or zygote, and thereby effected the right mutations? And if the Designer could make all of those miraculous changes one by one, then why not just pop whole new species into existence instead of all that wrangling with the tiny stuff over eons to make it look like species evolved? And why not keep popping new species into existence today so people can see it happening? After all, we have instruments that can detect micro–particles popping into existence today, but wouldn't it be great if more people could see a whole species pop into existence? Or even if scientists could see whole chromosomes appear instantaneously out of thin air while examining cells under microscopes?

And if the Designer accomplished his purposes via endless tiny mutation events over eons of time did the Designer also have to keep a watchful eye on DNA Heʼd just changed, to ensure no more mutation-causing chemicals or cosmic rays touched this or that part of the DNA to reverse each change, or to ensure the zygote/embryo/fetus was carried safely to term and thus ensure the passing along of each new genetic change the Designer had just instituted? Did The Designer also have to monitor each animal born with such new mutations to ensure it was not taken out of the gene pool by random contact with a deadly microorganism, or random contact with some nearby predator or natural disaster, so that the newly instituted genetic changes would survive and the organism reach the age of sexual reproduction and pass along such changes?

My point is that curious scientists continue to search for connections in nature, how things are related to one another, not how they are discontinuous from one another as I.D.ists seem to be concluding rather impatiently. Most scientists are not impatient when it comes to continuing to asking questions concerning how things in nature are connected to one another, how they all fit together. Questions like…

  1. How does something in the biological world work? How does it currently function. That's merely the beginning of examining questions pertaining to relationships in nature.

  2. What are all the known analogues in the biological world that resemble how that one thing works?

  3. What are a few hypothetical natural changes/alterations this one thing or its earliest ancestor might have undergone?

  4. Also, how many possible paths to genetic, behavioral and morphological changes are there? Only after knowing that can we begin to whittle down the most probable natural changes/alterations this one thing or its earliest ancestors might have undergone.

It takes a lot of patient effort and analysis in other words, to discover how things in nature are connected. But we have discovered plenty of connections throughout nature.

I.D.ists like Behe simply regurgitate in their books the very first question above, listing what scientists have discovered about how something in nature works (like the flagellum) and continue to harp on how it all fits together. Yes it does. But did it always fit together exactly like that over the billions of years in the past when the earth was filled with nothing but single–celled life forms? The flagellum most probably arose at a time when bacteria were exchanging DNA actively–and also absorbing any DNA they came across passively–for probably over a billion years. To trace all possible changes in the DNA of such ancient bacteria over that length of time is impossible at present. There are nearly no fossils of ancient bacteria, nothing like the fossils we possess of the bones of ancient vertebrates and how their modes of transportation changed over time, i.e., from fins to limbs among vertebrates. Nor do fossils of ancient bacteria reveal their inner cellular structure. So there's much information we are missing. And many questions remain concerning what happened during the billion years when the earth was filled with only single–celled organisms.

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