No more Cambrian woes for evolution


Photo: Upper Ordovician fossil Bryozoa, by Wilson44691, CC BY-SA 3.0 , via Wikimedia Commons.

If new fossils could save Darwin from his Doubt and Dilemma, they would have already arrived. Instead, they continue to illustrate another image: an abrupt appearance and a clever design.

And you, Bryozoa?

Stephen Meyer can add another phylum to his chart of body planes in the Cambrian Explosion (Darwin’s doubt, p. 32): Bryozoa branch.

Bryozoa, formerly called Ectoprocta but now Bryozoa again, are small animals that live in colonies. The colonies resemble moss in texture, hence the name Bryozoa, “moss animals”. Growing only around 4mm in size, individuals (called zooids) bind together in tissue-like structures up to 3 feet in width. Zooids perform different functions to support the colony: feeding by filtration, defense and reproduction. Some 5,000 species are known, inhabiting both fresh and salt water, and in tidal pools to deep ocean trenches. Animal Fact Sheets has some live bryozoan video clips on YouTube.

Bryozoa may appear simple, but they are capable of sexual reproduction as well as hermaphroditism and budding. Despite their small size, they have a digestive system and mobile eyelashes. Long considered to have appeared in the Ordovician (485 million years ago, the oldest fossils in China), bryozoa have now been confirmed in the early Cambrian. In News and opinions about nature, Andrej Ernst and Mark A. Wilson write: “Bryozoan fossils finally found in Cambrian period sites. They had been “conspicuously absent” so far. Why is that ? Thinking of Darwinly, Ernst and Wilson point out that “Bryozoa have a complex shape (morphology) and therefore must have already had a long evolutionary history”. Molecular studies had also suggested to evolutionists an earlier emergence.

This emergence is now confirmed at least 35 million years earlier in the evolutionary timescale, or 44 million years depending on the molecular clock. Ernst and Wilson, announcing the main paper in the same issue of Nature, make a bold evolutionary claim:

Write in Nature, Zhang et al. present a collection of fossils from ancient Cambrian deposits in China and Australia that are unequivocal bryozoa, and thus present proof that solves one of the mysteries surrounding early animal diversification. [Emphasis added.]

And now the hard part

How can this solve the mystery of early animal diversification? Does the addition of independent suspects solve a murder mystery? The only reason they give is that the earliest Cambrian “ancestors” of Bryozoa had soft bodies and most Ordovician species had hard parts:

Zhang and colleagues’ study shows that the evolution of bryozoans had a notable history, previously hidden in the early Cambrian. Although it has been assumed by many researchers, it is only now that there is reliable evidence for it. The absence of hard parts of the skeleton in P. gatehousei Explain why bryozoans were previously missing in the Cambrian fossil record….

Now that this ancestral mystery has been solved, attention can be focused on the evolutionary history of bryozoans from the early Cambrian to the early Ordovician.

The hard parts could explain the preservation of bryozoans, but not their origin. This last question is certainly the real “hard part” of the story. Meyer’s main question resonates in the eight years since the release of his book: What was the source of the information for the complex body plan of this one and the 20 or so other animal phyla that exploded onto the scene in the early Cambrian?

These Cambrian bryozoans were not really simple. With the exception of the skeletal parts, they remarkably resemble Ordovician species. They had a spike, “suggesting an erect, self-sustaining colony anchored to the substrate.” The new species also cannot be considered a common ancestor of bryozoans, as it already contained characteristics of other families. Indeed, “the last common ancestor of Bryozoa of the total group remains enigmatic”, admit the authors.

Photos of the fossil specimens and the following description reveal that this was another complex body plane unrelated to other phyla that suddenly arose in the early Cambrian.

The network of honeycomb zooids in P. gatehousei [the new fossil] shows that the hierarchical architecture and complexity of colonial life was also an important evolutionary innovation during the Cambrian radiation of animal life.

Innovation is a euphemism for a sudden onset without an intelligent cause. This quote speaks for itself:

The interpretation of this secondarily phosphated fossil from the Lower Cambrian rocks of South China and South Australia as a putative bryozoan indicates that modular bryozoans evolved synchronously with most of the other metazoans of the stem group during the Cambrian evolutionary radiation.

A correction is in order: he was not a “Cambrian evolutionary radiation. ”It was a“ Cambrian explosion ”of fully functioning animals with hierarchical body planes that challenge evolution. The only cause that can account for the hierarchical functioning of systems is intelligence.

Ordovician impact

Speaking of the Ordovician, it exploded too. The “Ordovician radiation” saw a rapid diversification of bryozoans and everything else under the sea. University of copenhagen Explain :

In a geological period 469 million years ago known as Ordovicium [sic] Back then, Earth’s seas were inhabited by animals like trilobites (reminiscent of woodlice), conodonts (eel-like vertebrates), and brachiopods (animals with two-part shells reminiscent of seashells).

But suddenly something happened which has become crucial for life to evolve into the life we ​​know from today’s oceans. Marine biodiversity has quadrupled in a few million years. In reality, it was the greatest increase in biodiversity in the history of our planet.

Now for the punch line: it was an asteroid that exploded. Or, maybe it wasn’t. Previously, evolutionists believed that this “greatest increase in marine biodiversity on Earth was not due to the explosion of an asteroid,” but experts in Copenhagen now know better. It was climate change.

“Instead of triggering an increase in biodiversity, the cosmic dust from the asteroid explosion probably acted as a temporary brake on the evolution of species. The dust blocked the sunlight, which altered most photosynthetic processes – and consequently the living conditions of animals in general, ”says Jan Audun Rasmussen, curator and researcher at Museum Mors and lead author of the study .

These evolutionists do not deny the explosion of asteroids; they only remove it as the cause of Ordovician radiation. He did the opposite, they say; it slowed down “the evolution of species”. Pity; evolutionists probably cannot now conjure up an asteroid to explain the Cambrian explosion.

The new story is that the Milankovich cycles cooled the planet, and the global cooling caused the explosion of diversity. This explanation is given in Nature Communication by Rasmussen et al., “Middle Ordovician astrochronology decouples asteroid rupture from glacier-induced biotic radiation.” Hey; climate change is all the rage these days. Why not try this on the Cambrian explosion? Add a little heat; remove some heat; who knows what climate change might do for evolution?

Sponge nerves

The power of suggestion has hypnotized Max Koslov and his experts Nature: they imagine “precursors of the nervous system” in sponges.

Based on the proximity of the two cell types and the expression of genes that strength allow the secretion of chemicals, researchers think that these arms allow the neuroids to communicate with the choanocytes, so that they can pause the water flow system and remove any foreign debris or microbes. However, these neuroid cells are not nerves, and there is no sign of the synapses that allow neurons to communicate so quickly. Instead, this type of cell could represent an evolutionary precursor of a true nervous systemsays Jacob Musser, an evolutionary biologist at EMBL, who is a co-author of the study. “We’re at an intermediate point, where you’ve gone from all those independent pieces to bring them together more broadly, but you haven’t gotten all the interconnectivity you need to create a rapid synapse, ”he says.

Without a doubt, sponges are successful animals since they are still with us today. But even other evolutionists are putting pressure on the notion.

Some scientists say that to call these cells a precursor to a nervous system is a stretch. “His tempting, but it’s hardly definitivesays Linda Holland, evolutionary developmental biologist at the University of California at San Diego. She says it will be hard to prove whether the nervous systems evolved from this cellular communication system or occurred earlier or even several times, as some groups have suggested. Indeed, many other organisms, including single-celled eukaryotes, contain the same synaptic genes, says Sally Leys, a marine biologist at the University of Alberta in Edmonton, Canada.

Meanwhile, the Cambrian explosion remains a mystery to those who deny intelligent design. Evolution is advancing. Maybe the payoff is the process, not the proof.


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