Stretching Out the Cambrian Explosion

Posted On Dec 19 2019 by

first_img“Dawn of the animals: Solving Darwin’s dilemma” is the confident-sounding title of an article about the Cambrian explosion in New Scientist.  Their solution, however, did not include finding transitional forms.  It revolved around “setting the stage” environmentally for the sudden appearance of complex animals.    Reporters Douglas Fox and Michael Le Page began by comforting Darwin.  He would not be as forlorn today about the problem for which he said, “I can give no satisfactory answer.”  Look at all the new evidence that has turned up since he died:Of course, we have since discovered innumerable fossils from far earlier periods.  Rocks as old as 3.8 billion years contain signs of life, and the first recognisable bacteria appear in rocks 3.5 billion years old.  Multicellular plants in the form of red and green algae appear around a billion years ago, followed by the first multicellular animals about 575 million years ago, during the Ediacaran….None of this addresses the primary issue of the dilemma, however – the sudden appearance of virtually all the animal body plans at the base of the Cambrian.  They realize this, so they quickly shifted gears: “Even so, many perplexing questions remain,” they said.  “Why did animals evolve so late in the day?  And why did the ancestors of modern animals apparently evolve in a geological blink of an eye during the early Cambrian between about 542 and 520 million years ago?”  This brief hand-wringing exercise switched quickly back again to an all-clear sign: “A series of recent discoveries could help explain these long-standing mysteries.”    Here’s their synopsis in a nutshell.  Sponge embryos found in China push back the appearance of multicellular animals (albeit simple ones) as far back as 580 million years – maybe even 632 million, at the beginning of the Ediacaran era, “suggesting that the animal embryos themselves go back this far.”  (We will assume their dates for the time being.)  So far, they have only shifted the date of the problem, not the problem itself.  An embryo is a complex structure that presupposes many complex multicellular processes already in action.    But “Other, more tentative findings push the dawn of animals back even further,” they announced.  Don’t wait for nice, clean fossils, though.  The findings amount to little more than quantities of 24-isopropylcholestane found in Arabian oil, interpreted by two MIT professors as evidence of a large quantity of sponge material going back as far as 713 million years ago.  Still just stretching dates, they next cited some stromatolites in Canada with “patterns as a characteristic of a collagen mesh – something only animals build.”  The date: 850 million years ago.  Note that this is not actual collagen.  It’s just a pattern in some rocks the resembles a collagen mesh.  It’s discoverer said that it “looks very primitive.”    From there, Fox and Le Page turned to Andy Knoll of Harvard for help.  He looked at his molecular clock evidence and also found animal life at least 800 million years ago; “This goes a long way toward reconciling the geologic record with molecular clock estimates,” he said.  Surprisingly, even though “he thinks animals probably did evolve early on,” Knoll was not convinced by the oil evidence or stromatolite evidence Fox and Le Page had just cited.  “The case for early animals is not yet rock solid,” they said.    In lieu of evidence, they decided to speculate on the question of why the evidence is missing.  By speculating that the Chinese embryos could represent cysts formed under hard environmental conditions, they wove a war story about bacteria battling the emergent complex life.  Bacteria kept the oceans anoxic (free of oxygen), stole nutrients, and produced toxins like hydrogen sulfide that kept the embryos in their shells.  Knoll said, “Eukaryotes would have been uninvited guests.”    Eukaryotes got their chance when the planet entered a Snowball Earth stage.  Ice ages cleared the playing field and, for once, allowed animals to get an upper hand.  The reporters quoted a biogeochemist who said, “You have changes in ocean chemistry like an increased availability of molybdenum and zinc, all of which play into making the world more hospitable for eukaryotes and ultimately, metazoans” (multicellular organisms).  The evolutionists seem to be thinking, “If you build it, they will come.”  Sure enough, “Sponges or something like them would have been the first animals on the scene,” Fox and Le Page speculated, not specifying where they came from.  “They lack a nervous system and have no need for circulatory systems.  Animals like jellyfish might also have evolved early.”  Somehow, central nervous systems showed up at the table, too.    But animal life was tough at first.  That’s why the missing evidence.  They didn’t have hard shells, for one thing.  And they were tiny.  Until they ate the bacteria and got larger, they couldn’t betray their presence.  Slowly, they devoured the rulers of the oceans: the bacteria.  “By doing so, they would have introduced selective pressure for organisms to get larger, to avoid being eaten.”  Eaten?  By what?  They didn’t say; perhaps by cannibals.  Whatever; this process, driven by selective pressure, introduced oxygen into the ocean depths and changed the world forever.  The table was set; the dawn was appearing; the fuse for the explosion was lit: “As the oceans changed, the stage was finally set for the evolution of more sophisticated body forms.”    How did setting a stage produce the actors and the play?  Instead of answering that question, they digressed briefly into a discussion of whether the changes in ocean oxygenation were a cause or effect of the evolution of complex animals.  Once the playwright and director agreed it was the latter, they role-played the script without any actors to call on:For a while the climate bounced between wild extremes: during warm periods complex life thrived and lots of carbon was locked away, leading to deep ice ages.  During the ice ages, carbon burial ceased, and the planet warmed again.  These swings ended only when burrowing creatures with a gut evolved towards the end of the Ediacaran, [Martin] Brasier [U of Oxford] thinks.  By recycling the organic matter falling to the sea floor, they reduced carbon burial and stabilised the climate.  “There are no Snowball Earth glaciations after big animals evolve,” he says.The evidence will show up any day now, in other words, because the actors must have been there somehow or other.  The playwright and director still have a nagging question about this plot.  “But if the evolution of animals really did trigger the ice ages and the oxygenation of the oceans, rather than the other way round, why didn’t animals appear much sooner?” they say.  “After all, single-celled eukaryotes were around from 1.5 billion years ago, and possibly much earlier.”  Somewhere Darwin’s dilemma got inverted.  The audience thought they were going to hear a play about how animals evolved – not a statement that they did evolve.    That question aside, what did they conclude about the late appearance of animals?  They called on expert Nick Butterfield [U of Cambridge] to explain.  “Butterfield thinks the main reason animals evolved relatively late in Earth’s history was the sheer difficulty of evolving the cell adhesion and signalling machinery necessary for cells to work together.  Once these basics were in place, though, the pace of evolution began to quicken.”  It just took a long time, you see, for Evolution to figure out the technology.  The authors leave that problem to Evolution.  Evolution guarantees the basics will be “in place” on cue.    Fox and Le Page, apparently satisfied with all this role-playing, ended with a synopsis of the play: the war between the bacteria and the newly-evolved complex life, the battle over carbon and oxygen, the sudden ice age, and the new environment: “The surviving animals seized the opportunity to wrest control of the oceans from the bacteria, producing clear waters rich in oxygen in which larger, more complex animals could evolve,” they said, in an air of triumph.  The rest is easy: “Thus the stage was set for the Cambrian explosion.”    As the curtains close, an announcer steps out for one final word to the audience.  “Of course, fossil hunters are going to have to do a lot more digging to confirm these startling new hypotheses.”  Brasier sticks his head out of the curtain to add a last word – “I suspect things will turn up, but if they don’t we have to listen to the evidence.”If a perceptive audience were watching this farce, they should be erupting in belly laughs in unison at that last line.  That’s hilarious!  “I suspect things will turn up, but if they don’t we will have to listen to the evidence.”  Well, my dear chap, after 150 years, it’s about time!    If you are not convinced by now that the reporters at New Scientist are irrational Darwin Party ideologues pushing their faith against the evidence, read what they said again more carefully.  The number of propaganda tricks and logical fallacies they just committed are legion.  They started with a bluffing title and opening as if the problem has been solved at last.  They used euphemisms to sugar-coat the seriousness of the problem.  They used high-handed card-stacking by selecting only the authorities that supported their weird-science myth.  And they sidestepped the real issue by talking about oxygen, carbon, and ice instead of how complex animal body plans (with eyes, articulated limbs, nervous systems, digestive systems and much more) could arise by a Darwinian process.  They begged the question about how animals evolved by simply assuming that they did!  Pull out your Baloney Detector and count how many other violations they were guilty of.  It looks like a few of the readers making comments at the end of the article were up to their tricks.    Let’s get some clarity about this magical phrase they used, “selective pressure.”  They used the power of suggestion to conjure up a mystical guiding hand of Evolution that steered the hopeful cells toward eukaryotic multicellular bliss.  Foul!  Selective pressures are mindless boundaries, that’s all.  They could not care less about what life wants to do (as if animals without sentient brains could want to do anything anyway).  Gravity, for example, is a selective pressure.  It naturally selects people who do not jump out of windows.  It also selects against lizards that fall out of trees.  The selective pressure has no desire or power to create wings; it is just a filter against entities that do not have wings.  Darwinists use this phrase “selective pressure” to distract the reader from using common sense.  They never quite get around to answering the question of how the wings arose.  Well, it certainly was not by selective pressure.  Natural selection is an unguided, mindless process, remember?  It has no foresight.  It cannot pressure anyone or anything to go against what the laws of nature demand in the immediate circumstances.  No wings, matey?  Sorry, you get selected against.    After all their huffing and puffing, Fox and Le Page deflated their balloon with that last admission: “I suspect things will turn up, but if they don’t we will have to listen to the evidence.”  Ha!  They just admitted their story has no evidence.  In a sense, they have no innocence, in essence.  In no sense does the evidence support evolution.  Then we heard them make a promise: to listen to the evidence.  Let’s hold them to it when the new film Darwin’s Dilemma: The Mystery of the Cambrian Fossil Record from Illustra Media hits the market this summer (watch the trailer).  It will present a lot of evidence.  Let’s see if these ideologues will keep their word and listen to the fossil evidence that is screaming at them.(Visited 18 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img

Last Updated on: December 19th, 2019 at 3:14 pm, by

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