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Explaining Animals: A Random Walk

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random walk

 Darwin devolves, but evolution evolves. Since Darwin’s famous admission of ignorance about the sudden appearance of animals in the Cambrian, the evolving story of their origins has resembled a drunken sailor’s walk, stumbling in various directions and sometimes crossing over previously abandoned paths, but never making progress despite his happy songs. Even with the advent of rapid genome sequencing, and with exceedingly more fossils to look at, evolutionists strut about aimlessly, thinking they are getting closer to the ultimate phylogenetic tree.

A Trilobite Rex

To see what evolutionists are up against, read about a giant trilobite found in Australia. Researchers at the University of Adelaide called this foot-long monster a “king of fossils”:

“We decided to name this new species of trilobite Redlichia rex (similar to Tyrannosaurus rex) because of its giant size, as well as its formidable legs with spines used for crushing and shredding food — which may have been other trilobites,” says James Holmes, PhD student with the University of Adelaide’s School of Biological Sciences, who led the research. [Emphasis added.]

This monster moved. It ate. It sensed. It had a complex body plan, with numerous cell types arranged hierarchically into tissues, organs, and systems. It’s 500 million years old, and it’s just as complicated as its predecessors 21 million years older. Trilobites are found all over the world, from California to China, from Australia to Greenland. Where did they come from?

The Phylogeny Storytelling Game

Since most journals have sworn allegiance to Darwin, they are stuck with Darwin’s blind processes to explain the origin of animals such as Trilobite Rex. But if, indeed, animals were designed, accounting for them otherwise is doomed to failure. The vision of the ultimate phylogenetic tree lures scientists on, like children told that fireflies in the woods will lead them to treasure. They follow one till it blinks out, then another, then another, thinking they are making progress. The search has become a game to see how many of their friends will follow the same firefly for a while, when none of the fireflies have anything to do with treasure. Follow along as they hunt for enlightenment.

The King at War

The Adelaide team realizes that the data are not indicative of slow-and-gradual evolution:

The finding is adding important insights to our knowledge of the Cambrian ‘explosion’, the greatest diversification event in the history of life on Earth, when almost all animal groups suddenly appeared over half-a-billion years ago.

What could have sped up this evolutionary burst? They try the “arms race” theory:

One of the major drivers of the Cambrian explosion was likely an evolutionary “arms race” between predators and prey, with each developing more effective measures of defence (such as the evolution of shells) and attack.

But necessity is the mother of invention only for minds. Humans design weapons and counter-measures. Maybe that is why they hedged their bets with qualifiers: an arms race was “likely” only “one” of the major drivers of the Cambrian explosion. Well, then, what were the others? Oxygen? New niches? A hidden long fuse? When Darwinism is the theme, endless variations are possible without a finale.

Magic Cells

A long drive north from Adelaide, scientists at the University of Queensland “have upended biologists’ century-old understanding of the evolutionary history of animals.” Any understanding that has been upended was never understanding in the first place. But this is another way to get attention for your firefly: tell everyone that their firefly is the wrong one. The Queensland team says everybody took a wrong turn further back in time, when the first multicellular animal was born.

The findings disprove a long-standing idea: that multi-celled animals evolved from a single-celled ancestor resembling a modern sponge cell known as a choanocyte.

But sponge choanocytes, they say, only look like free-living choanoflagellates. Their transcriptome signatures “simply don’t match,” says Associate Professor Sandie Degnan. “We’re taking a core theory of evolutionary biology and turning it on its head.” What was the single-celled ancestor? Turn off the empirical lights. Just imagine.

“Now we have an opportunity to re-imagine the steps that gave rise to the first animals, the underlying rules that turned single cells into multicellular animal life.”

Come back later, they suggest. But as a teaser, they hint, “The great-great-great-grandmother of all cells in the animal kingdom, so to speak, was probably quite similar to a stem cell.” What a totipotent cell this must have been. It could give rise to anything, even a Trilobite Rex!

Covering Assets

Two papers in Current Biology smother ignorance in jargon. Readers not fluent in terms like lobopodia, ecdysozoa, synapomorphy, and the like, might miss the points that are in plain English: evolutionists have no idea what they are talking about. The first paper by Ferdinand Marlétaz, “Zoology: Worming into the Origin of Bilaterians,” begins:

The nature of the last common ancestor of all bilaterally symmetrical animals — the urbilaterian — is one of the key questions in zoology, partly because it reflects on the origin of the key organ systems that make us who we are. There are two opposing views of what this ancestor may have been like — either it was a rather simple organism or a fairly complex one.

OK, well. That seems intuitive. Can he be more specific? 

He cannot, because after pages of possibilities, debates, conflicting evidence and mismatches between molecular data and fossils, he concludes, “animal phylogeny remains a difficult matter.” Several possible approaches to all the problems are suggested, even though more data are unlikely to help. 

Of course, more species and better data might alleviate some biases and provide marginal gains in phylogenetic resolution but will be unlikely to provide a major step forward.

One way to avoid embarrassment with such a bleak outlook is to sound excited. He ends, “These prospects show that molecular phylogeny is still a lively field.” 

Rearranging Leaves on Renamed Branches

The other strategy for masking ignorance, displayed by Giribet and Edgecombe in “The Phylogeny and Evolutionary History of Arthropods,” is to look busy by rearranging branches on Darwin’s tree. Smothering readers with more jargon, these evolutionists offer nothing solid to grasp in their quest to explain arthropods, the largest group of animals in the world. (Trilobite Rex, remember, is an arthropod.) 

In their survey of all the arthropod families, and discussions about how they fit into evolutionary trees, the word “debate” appears frequently. Some debates, the authors claim, have been resolved by molecular techniques and tree-building software models. But those alleged victories do not rest on transitional forms or evidence of genetic innovations. They rely only on which models feel more satisfying to them, even if they had to move animals into different groups or invent new taxonomic categories to put them in. 

The evolutionary history of arthropods is illuminated by a rich record of fossils, often with exquisite preservation, but current analyses conflict over whether certain fossil groups are stem- or crown-group arthropods. Molecular time-trees calibrated with fossils estimate the origins of arthropods to be in the Ediacaran, while most other deep nodes date to the Cambrian…. Confidently placing some key extinct clades on the arthropod tree of life may require less ambiguous interpretation of fossil structures and better integration of morphological data into the phylogeny.

That’s a huge conflict right there: molecular methods place arthropods in the Ediacaran (where nothing moved or flew), but fossils put them in the Cambrian. In fact, they state that “Arthropod body fossils, including the first trilobites, appear about 521 million years ago (mya),” admitting that they “appear” suddenly, without actually using the word “explosion.” Later, they say,

The divergence between these clades is consistently dated to the Precambrian with molecular techniques, usually to the Ediacaran Period, although no body or trace fossil evidence for arthropods occurs in sediments older than the earliest Cambrian.

Many arthropods can fly. How did that happen? It just did! It evolved —

The evolutionary success of insects is unquestionably linked to the advantages offered by the evolution of flight.

Why must it be an “evolutionary success” instead of just a success? Why must they speak of the “evolution of flight” instead of just flight? Do they offer any transitional forms? Do they present new flight genes that got naturally selected? No; this is all a game of cramming observations into a preconceived belief. In Darwinian thinking, if something is there, it must have evolved. 

Giribet and Edgecombe frequently describe conflicts between molecular data and fossils. They end hopefully that “the future of arthropod phylogenetics looks brighter than ever,” while admitting that “some recalcitrant questions remain.”

Fundamental evolutionary questions, such as how and how often arthropods transitioned from water to land or how pterygote insects evolved the ability to fly, are centered on debates about phylogeny (e.g., choosing between candidates for the closest relatives of insects, and determining whether land-dwelling arachnids have a single origin).

Why all the trouble? Why all the debate, and admissions of ignorance? Why the never-ending random walk? Is it not because these scientists are “centered on debates about phylogeny” to the point that they cannot let the evidence speak for itself?

Image: Redlichia rex, by Katrina Kenny via University of Adelaide/EurekAlert!