Sunday, August 20, 2023

From Bad to Worse for Darwinism, as New Cambrian Explosion Finds Arrive

David Coppedge 

 More bad news for Darwinism arrived after my last article about Cambrian Explosion. I showed there that taphonomic conditions should have produced Precambrian animal fossils had they existed. Now, some of the other props for Darwin’s House of Cards have been removed. Tom Bethell had said in that book, “The near-instant explosion of body plans is the opposite of what Darwin’s theory predicts” (p 134). Oxygen Theory Deflated “No, oxygen didn’t catalyze the swift blossoming of Earth’s first multicellular organisms,” begins some news from the University of Copenhagen. “Life on Earth didn’t arise as described in textbooks.” What? Textbooks wrong? Shocking! “The fact that we now know, with a high degree of certainty, that oxygen didn’t control the development of life on Earth provides us with an entirely new story about how life arose and what factors controlled this success,” says the researcher, adding: “Specifically, it means that we need to rethink a lot of the things that we believed to be true from our childhood learning. And textbooks need to be revised and rewritten.” [Emphasis added.]

 Textbooks had been saying, “increased oxygen levels triggered the evolutionary arrival of more advanced marine organisms.” Scientists at the university, with international peers, claim that the oxygen theory “is being disproved” by measurements of oxygen levels in rocks dating from “the Avalon explosion, a forerunner era of the more famed Cambrian explosion.” The Avalon Explosion they date at “between 685 and 800 million years ago.” Defying expectations, the result shows that Earth’s oxygen concentrations had not increased. Indeed, levels remained 5-10 times lower than today, which is roughly how much oxygen there is at twice the height of Mount Everest. Evolutionists have a strained relationship with oxygen. They don’t want it at the origin of life, but they were relying on it to power the Avalon and Cambrian Explosions. And in modern times, they struggle with the complexity of molecular machines that protect life from Reactive Oxygen Species (ROS). Current atmospheric oxygen levels appear finely tuned for complex life, as biologist Michael Denton argues in Fire-Maker. We have a Goldilocks value that balances the advantages of oxygen for metabolism against the disadvantages of too much or too little. 

 Time Squeeze 

 A different paper last month in PNAS, by Lyle Nelson and scientists from Canada and the U.S., has more bad news for those who want to stretch out the duration of the Cambrian Explosion. The early Cambrian Period marks the important interval when most major groups of animals first appear in Earth’s sedimentary record. The tempo of this biological diversification is still poorly defined because, globally, there are few absolute age constraints that calibrate early Cambrian fossil occurrences or the carbon isotope perturbations used to correlate the biostratigraphy of different continents. In this study, we present high-precision age constraints for strata in the southwestern United States, which suggest the early Cambrian animal radiation was significantly faster than currently recognized. Accurately constraining the timing and rates of early animal evolution is a critical step toward better understanding this milestone in Earth’s history. The authors measured “precise zircon U–Pb dates for the lower Wood Canyon Formation, Nevada,” which lies in the southeastern Death Valley region. Their measurements constrain the onset of the explosion to “younger than 533 Mya, at least 6 My later than currently recognized.” Out with 540 Mya; in with 533 Mya as the new official “onset of infaunalization” (the sudden appearance of complex animal body plans). Formally, the base of the Cambrian is now defined by the first appearance of an ichnofossil assemblage that includes Treptichnus pedum, a distinctive branched, bilaterian trace fossil, interpreted as potentially formed by priapulids. The inclined branches of T. pedum are the earliest examples of systematic probing of the substrate, thus marking the onset of infaunalization that is pervasive in the Phanerozoic sedimentary record. Priapulidae are complex animals, still extant today, that reproduce sexually and have a true coelum (body cavity), muscles, nerves, and a through gut. If the trace fossils are from one of these phylum members, they represent a significant level of “infaunalization” indeed. 

 Phylum Squeeze 

 The famous Burgess Shale (pictured above), the showcase of early Cambrian animals, has produced another taxonomic group: the earliest swimming jellyfish (phylum Cnidaria, subphylum Medusozoa). The Royal Ontario Museum (ROM) announced this month the discovery of “well preserved” fossils of Burgessomedusa phasmiformis, a newly-named jelly complete with a medusa (free-swimming) stage — the most advanced type. Other cnidarians (the phylum that includes corals and anemones) are known in lower Cambrian strata, but medusozoans are “the most efficient swimmers in the world” (here). Was this a primitive cnidarian? Jellyfish belong to medusozoans, or animals producing medusae, and include today’s box jellies, hydroids, stalked jellyfish and true jellyfish. Medusozoans are part of one of the oldest groups of animals to have existed, called Cnidaria, a group which also includes corals and sea anemones. Burgessomedusa unambiguously shows that large, swimming jellyfish with a typical saucer or bell-shaped body had already evolved more than 500 million years ago. Burgessomedusa fossils are exceptionally well preserved at the Burgess Shale considering jellyfish are roughly 95% composed of water. ROM holds close to two hundred specimens from which remarkable details of internal anatomy and tentacles can be observed, with some specimens reaching more than 20 centimetres in length. These details enable classifying Burgessomedusa as a medusozoan. By comparison with modern jellyfish, Burgessomedusa would also have been capable of free-swimming and the presence of tentacles would have enabled capturing sizeable prey. The date given (505 Mya) is not significantly different from earlier estimates for medusozoans mentioned in my 2013 article about “instant body plans,” but it points to an even earlier first appearance: “Although jellyfish and their relatives are thought to be one of the earliest animal groups to have evolved, they have been remarkably hard to pin down in the Cambrian fossil record. This discovery leaves no doubt they were swimming about at that time,” said co-author Joe Moysiuk, a Ph.D. candidate in Ecology & Evolutionary Biology at the University of Toronto, who is based at ROM. If it was already swimming like a modern jellyfish, it had parents who swam, and ancestors who swam. This is among the earliest identifiable medusae, but its date necessitates earlier ancestors. One of those must have (in Darwinism) won the mutational lottery to start swimming freely. But it would have needed muscles, nerves, and sensory equipment to avoid floating off into evolutionary oblivion. Given that jellyfish rarely fossilize, being 95 percent water, it’s within the realm of possibility that earlier specimens may turn up some day even closer to biology’s big bang. 

 Majoring on Minors?

 Graham Budd and friends had a little spat with Nicholas Strausfeld about details of a Cambrian animal. The give and take in Science at the end of June concerned whether a lower Cambrian lobopodian named Cardiodictyon had a tripartite brain and thus represented the origin of euarthropod brains, euarthropods being the most complex group within the panarthropods. (Strausfeld et al. responded here). But surely there is a forest in these trees. Brains! Are they products of unguided natural processes? A look at the figures in their respective papers should astonish anyone that creatures with legs, antennae, mouth parts, guts, muscles, and central nervous systems should appear in rocks suddenly without precursors. Darwinians waste time trying to connect details of one tree to details in other trees, when the forest is shouting, “We were designed!” As new discoveries continue putting the squeeze on the Darwinian scenario, proponents of intelligent design feel no pressure. Complex life appearing suddenly, operating from day one with exceptionally rich functional information, is just what we would expect from engineering genius.