Rethinking the Cambrian Explosion

According to the Discovery Institute, the so-called Cambrian explosion was a magic moment when their intelligent designer — blessed be he! — came to this privileged planet to tinker with the primitive biosphere in order to create the basic forms of life we now see.

Darwin’s Doubt by Stephen Meyer, Vice President and Senior Fellow of the Discovery Institute (and a central figure in the infamous Sternberg peer review controversy) is all about the wonders of the Cambrian explosion that Darwinism can’t explain.

Wikipedia’s article on the Cambrian explosion takes a somewhat less supernatural view. Anyway, things may be changing, according to a press release from the University of Edinburgh (where Darwin briefly studied medicine). It’s titled Records prompt rethink of evolution milestone. Here are some excerpts, with bold font added by us for emphasis:

Scientists are rethinking a major milestone in animal evolution, after gaining fresh insights into how life on Earth diversified millions of years ago. Bursts of evolutionary activity that increased the number and variety of animals began earlier, occurred over a longer timeframe, and were more frequent than previously thought, researchers say. Their findings challenge a long-held theory that suggests the huge expansion in the types of animals on the planet more than 500 million years ago was triggered by a single, rapid surge of evolution – known as the Cambrian Explosion.

Will any of this upset the Discoveroids? Not really. The great thing about their “theory” of intelligent design is that it doesn’t matter what might be discovered. Anything and everything is compatible with the inscrutable activities of their supernatural designer — blessed be he! Let’s get back to the press release. It says:

Edinburgh geoscientists re-assessed the timeline of early animal evolution by analysing records of fossil discoveries and environmental change. Until now, the Cambrian Explosion – which took place between 540 and 520 million years ago – was thought to have given rise to almost all the early ancestors of present-day animals. Scientists say, however, that it was probably just one in a series of similar events, the first of which took place at least 571 million years ago during the late Ediacaran Period.

No problem for the Discoveroids. That’s how the designer does things. Okay, one last excerpt from Edinburgh:

The bursts of evolutionary activity may have coincided with dramatic fluctuations in the levels of oxygen and essential nutrients in the oceans, the team says.

Here’s more information from PhysOrg: Ancient records prompt rethink of animal evolution timeline. They say it was Professor Rachel Wood of the University of Edinburgh’s School of GeoSciences who led the study. Here’s a link to her paper, published in Nature Ecology & Evolution: Integrated records of environmental change and evolution challenge the Cambrian Explosion. You need a subscription to see more than the abstract.

Now we’ll sit back and wait for the Discoveroids to respond.

Copyright © 2019. The Sensuous Curmudgeon. All rights reserved.

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48 responses to “Rethinking the Cambrian Explosion

  1. One problem with getting overexcited about the Cambrian Explosion is that it ignores the rest of life. This chart gives a fairer view. We’re animals, and we’re excited about where we came from, but let’s not imagine that life is just animals. Was the development of animals any more marvelous than any other group?

  2. “According to the Discovery Institute, the so-called Cambrian explosion was a magic moment …..”
    A moment that lasted at least 20 million years and there is no contradiction here according to the IDiots from Seattle.

    “Will any of this upset the Discoveroids?”
    On the contrary – “scientists are rethinking” in an IDiot mind proves that athiest evilutionists had it wrong all the time, so IDiocy is correct.

  3. One of the things Meyer tried to establish in ‘Darwin’s Doubt’ was the lack of antecedents for the Cambrian biota in the fossil record.

    But if people look hard enough, they generally find what they’re looking for. Meyer looked for God in the Cambrian, so it’s no surprise what he found there. But the real interest lies in what discoveries, and connections, will be made as the earlier fossil organisms — from the Ediacaran, for instance — are more fully analyzed and classified.

    And even if those preceding forms turn out to be an evolutionary dead end, it still leaves us with the mystery of: why “design” them in the first place, only to have them wiped out in a mass extinction, and start from scratch for the Cambrian proper?

  4. Charles Deetz ;)

    So did the creator just create, or did he create and keep tinkering? Yes. Can you tell the difference? No. Did it take a moment or 20M years or 500M years? Yes. Can you tell where the creator stopped and nature took over? No.

  5. @Bob Seidensticker: Exactly! Thank you.

    It seems that the “Cambrian Explosion” was simply the appearance of hard body parts that fossilize well. The various families of living organisms already existed; it’s just that they didn’t fossilize well before.

    Why did hard body parts appear in the Cambrian? Perhaps it was a change in ocean chemistry, perhaps it was simply evolution. At any rate, having hard shells and other hard structures would certainly be an evolutionary advantage that would spread rapidly, giving the appearance of an “explosion” — if you could call something taking millions of years to develop an explosion.

  6. How boring to be a straight vanilla kind of god — the kind who just has a moment of creative explosion in the regular way. Much more deeply pleasurable to be the kind of god who has multiple creative explosions — bang! bang! bang! — one after the other.

    AAAAAHH! Then you can have a nice, long sleep.

  7. Karl Goldsmith

    But God did that more than once, don’t forget whales and modern turtles are just two examples of God having to redesign.

  8. You know how it works, KG. Redesign is also evidence for the Grand Old Designer (blessed be MOFO!).

  9. To what extent is the whole thing a trick of perspective? What are now the mighty boughs of an ancient oak tree started out as twigs. Were the divergences between what became separate phyla any more dramatic at the time than the formation of new species in the Pleistocene? [This is not a rhetorical question, but a request for information]

  10. @PB
    I recall one ID advocate saying that according to evolution we would expect that speciation would occur before the generation of higher order taxa. But the fossil record shows that the highest order taxa appeared first: domains, only after that did kingdoms appear, then phyla, etc.

  11. BTW the plan of life that @Bob Seidenstecker presented differs from the interest in the Bible. The Bible only mentions that little area in top right. Animals and plants. With some generosity, maybe fungi, too, but I wonder whether fungi were accepted as living things – like the agent of fermentation, or mold.

  12. “Why did hard body parts appear in the Cambrian? Perhaps it was a change in ocean chemistry, perhaps it was simply evolution. ”

    The most recent idea I heard on this was that tube worm things developed a secretion that hardened the lining of their tubes, due to changes in ocean chemistry enabling silicate (?) and carbonate formation. The lining then moved from the burrow to the critter and voila!

  13. @docbill1351, that would only account for the tube worms and their descendants. I’ve heard it suggested that the development of predation and teeth pushed very hard towards the development of hard exoskeletons. I’ve also heard that changes in ocean water composition may have been important. Details anyone?

  14. And by the way, the diagram Bob Seidenstecker posted should make the IDers think (assuming any do) about the fantasy that their alleged designer designed the universe with us in mind. To paraphrase J. B. S. Haldane, their designer (blessed by he/she/it) must love prokaryotes inordinately.

  15. christine janis

    “But the fossil record shows that the highest order taxa appeared first: domains, only after that did kingdoms appear, then phyla, etc.”

    It only appears that way from a historical, human nomenclature perspective.

  16. Michael Fugate

    Paper’s conclusion:
    The Ediacaran–Cambrian palaeontological and geochemical records reveal a progressive addition of biological novelty of form and process, and complexity within the Metazoa. Highly heterogeneous and fluctuating redox conditions throughout the late Ediacaran–early Palaeozoic interval, with successive but temporary expansions of oxic seafloor and possibly changing availability of phosphorous and nitrogen, facilitated the transition from low-oxygen Proterozoic oceans to more extensively oxygenated Phanerozoic oceans and the rise of modern biogeochemical cycles. This geochemical instability may have driven pulses of evolutionary innovation, but biotic feedbacks are poorly understood. Ecological and evolutionary responses to this instability could have wide-reaching implications for discussions of gradualistic versus punctuated evolution.

    We argue that the record can be considered to be a succession of assemblages, with the establishment of Cambrian crown-group animal ecosystems built on several successive Ediacaran advances as well as environmental and biotic feedbacks. The oldest record of Ediacara-type macrofossils appears to be dominated by probable non-bilaterian metazoans, with bilaterian metazoans appearing by ~560 Ma. A reduction in diversity occurs at ~551 Ma and is closely followed by the appearance of the first biomineralised taxa, but a well-documented expansion of seafloor anoxia postdates these events. Bilaterians, including predators, diversify after an episode of widespread anoxia at the Ediacaran–Cambrian boundary, immediately succeeded by an inferred ‘oceanic oxygenation event’ at ~540 Ma. Inferred stem-group poriferans, molluscs and brachiopods were seemingly devastated by the early Cambrian Sinsk anoxic event (~513 Ma), in contrast to inferred crown-group bilaterian phyla, whose diversification continues through to the GOBE.

    There is currently no compelling evidence for either significant competitive replacement or biotic replacement from the latest Ediacaran to Cambrian. Indeed, we conclude that a discrete Cambrian Explosion event is difficult to temporally isolate, or indeed to define. The rise of early metazoans can be more simply and holistically recast as a series of successive, transitional radiation events, perhaps mediated via complex environmental change, which extended from the Ediacaran and continued to the early Palaeozoic.

  17. Indeed, as a matter of logic, the deepest branchings are the oldest branchings. The notochord when it first appeared was no great deal. Now consider the significance of the skull-backbone-tail system evolved from it

  18. @christine janis & @Paul Braterman
    Yes, it is a matter of logic. Yet when I first heard that argument, I was stymied. How can one explain that matter of logic?
    There is some complication to it, for the first living things had to belong to species as well as domains. But insofar as it is true, no matter how the varieties of life appeared,” by design” (whatever that means), by creation, by magic, “by chance”, by evolution, or by quantum mechanics, the higher taxa had to appear at the beginning. The first living things had to belong to a domain.

  19. Michael Fugate

    Isn’t it in part due to the difference between stem and crown groups? We have crown arthropods and crown molluscs which are quite different, but their stem groups would have been much more similar, no?

  20. The edicocaran fauna were first studied extensively by paleontologists focussing on Australian soft bodied invertebrates that start showing up almost 600 million years ago, well before the Cambrain period. Stromatolites and other life forms, like bacteria were present over a billion years ago. Some explosion.

  21. @Michael Fugate, that’s roughly what I said. The two branches from a Cambrian split, originally not all that different, will have been diverging and elaborating into massive distinct clades for >500 My

  22. @TomS is a bit desperate: “How can one explain that matter of logic?”
    You can’t. It works only because of 1) common descent and 2) 13,7 billion years. YECers reject both.
    As for the IDiots from Seattle: you know very well that they care even less about logica (which tries to guarantee coherence and consistency) than YECers, so explaining it to them is a mission impossible without Tom Cruise being involved.

    @MichaelF: spot on. Classification reflects the state of affairs right now, in the early 21st Century. It doesn’t necessarily reflect the state of affairs many million years ago. Evolution is a gradual process, hence the development of stem and crown groups is gradual too.
    That’s one difference between you and a creacrapper. When words don’t suffice to describe our natural reality you’ll blame the shortcomings of language. A creacrapper thinks that language determines our natural reality. Compare Gen. 1:3 “And God said ….” and Joh. 1:1 “In the beginning was the Word, and the Word was with God, and the Word was God.” In our 21st Century this idea is reflected in JK Rowling’s spells. Expelliarmus!

  23. I imagine an interbreeding population of miserable little worms 500 or 700 or whatever million years ago, which then split, maybe because of selection in different parts of its range, or just by genetic drift, into noninterbreeding species. As it turned out, one of these species is the ancestor of chordates (us), as well as other groups, and the other of molluscs and others. Any alien biologist carefully observing at the time would think this split no big deal.

  24. Hilarious: https://genuinearticlex7.com/2019/03/06/luke-warm-laodicea/
    The age old questions are being answered as the evidence grows but the false assumptions and dogma cover the eyes of the onlookers.

  25. christine janis

    I see that this repeats the commonly held myth that Mary Schweitzer was fired from the U of Montana because of finding dinosaur ‘soft tissue’. She did indeed leave, eventually because she graduated and took up a lectureship at UNC.

  26. @Michael Fugate, the second article states that no other group has replicated her identification of organic fragments. But https://www.nature.com/articles/ncomms8352 if I understand it correctly gives good mass spectroscopic evidence for the preservation of biological organic material, recognisable and to some extent classifiable by fragment mass spectroscopy.

    Does anyone know the state of play on this one? Some might be very reluctant to accept Schweitzer’s work because it seems to give aid and comfort to creationists, who do indeed use it despite her strong objections. Romantics like me would like to accept it as a Hero Upends Orthodoxy story. Where are we now?

  27. Michael Fugate

    Thanks Paul – interesting paper. You doubt know more about the spectral analyses than I do. If as they say it is common, then maybe the controversy will go away.

  28. Another possibility for the cause of the Cambrian “explosion” — the development of sexual reproduction. The mixing of genes made possible by sexual reproduction would exponentially speed the development of new species. Changes in ocean chemistry that allowed the formation of hard shells and other body parts would then give us a way to track that development that happened over 550 million years ago. And as Paul Braterman suggests, the development of predation would be a strong driving force of evolutionary change.

  29. Christine, Mark Armitage is a miscrosopy and tissue expert and he has predicted soft tissue is the norm. This has been progressing in the findings of others. The DOGMA blinds the eyes of those who would otherwise be scientists, but are not. They are priests in a religion of error. Several other problems have arisen also: https://genuinearticlex7.com/2019/03/06/luke-warm-laodicea/ CQ

  30. christine janis

    ‘Christine, Mark Armitage is a miscrosopy and tissue expert and he has predicted soft tissue is the norm’

    What’s so interesting about the discovery of preserved soft tissue in the fossil record (nobody has yet found actual, fresh soft tissue) is the astounding coincidence that it was first recorded at around the same time that we developed the technology powerful enough to detect it.

    I also note this statement, addressed to me, is nothing whatsoever to do with my post, where I noted that creationists often wrongly claim that Mary Schweitzer was fired from Montana State University* because of her ‘heresies’. She left the University because she finished her PhD there and got hired at UNC.

    *(apologies for error in earlier post of U. of Montana)

    BTW. Can you explain why such ‘dinosaur artifacts’ in your link only ever depict the dinosaurs featured in children’s books from the 1950s: “Brontosaurus”, Tyrannosaurus, Triceratops and Stegosaurus. Almost as if that were the only source available to those people who made them.

  31. @Christine Janis: To be fair, willingness to look may also be relevant, To take a historical case, IIRC one of the first Archaeopteryx skeletons ever found was cleaned, destroying what with hindsight (and fortunately we have photographs) was evidence of feathers

  32. Michael Fugate

    As Schweitzer mentioned, scientists were reluctant to destroy fossils in order to analyze. Just like you couldn’t learn much about human anatomy without dissecting bodies. And the dinosaurs I got a kid from Sinclair Oil (now on my office shelf) aren’t true to life? http://www.monsterbashnews.com/SinclairDinosaurs.html

  33. christine janis

    True, Paul, I was being a bit snarky. But the type of soft tissue described by Mary Schweitzer was only revealed due to pretty high tech investigation. Bone and blood are both tissues, but the former has a better likelihood of being preserved than the latter, due to the original tissue containing minerals.

    That being said, fossil leaves are indeed preserved soft tissue and have been known about for, I should imagine, centuries.

  34. christine janis

    ‘And the dinosaurs I got a kid from Sinclair Oil (now on my office shelf) aren’t true to life?’

    Ah, Sinclair Oil. Now, there’s preserved soft tissue for you —-

  35. @PaulB
    Who’s doing the looking? Not creationists. If it was up to them, they’d still be relying on the obsolete models presented in those children’s books. They’re 40 years out of date on dinosaurs, and when they do deign to keep abreast of the scientific developments — and not just mindlessly disputing the science because it contradicts their beliefs — they’re merely piggybacking on the honest labour of paleontologists and paleo-artists.

    Remember what Ham said? “We’re going to take back dinosaurs from the evolutionists.”

  36. Michael Fugate

    Oil wasn’t specially created on day 3 along with the land to provide us with an energy source? Didn’t God send creationist geologists to uncover coal, oil and gas reserves?

    Rock Art review
    https://palaeo-electronica.org/content/2012-issue-2-articles/128-321/277-rock-art-dinosaurs-figures

  37. I thought that oil and coal were the result of stuff being buried by Noah’s F;ood.

  38. @Michael Fugate, yes He did just that in the person of Steve Meyer, who worked for Atlantic Richfield for a while. But not even He could provide a Young Earth creationist who could do that

  39. Christine, you really need to take a look at Mark Armitage published peer reviewed papers as well as his videos. He found a horn in the ground open to the elements, with a scraping tool he peeled soft tissue from the mineralized bone stretched the soft tissue under the ,microscope all hardly new technology to allow new fangled science. All of you: Carbon date the bones. If there is carbon … Guess what? Chris Queen BSME prediction Carbon dating will yield results because the bones are under 50,000 years old. Chris Queen

  40. @genuine, do you really mean to tell us that you are unaware of the upper limit imposed on radiocarbon dates by adventitious contamination, such that one part in 1024 contamination of the surface by modern bacterial carbon will give an apparent age of ten half lives, around 57,000 years near enough, however old the specimen?

    For a fuller discussion, see Davidson and Wolgemuth (disclosure; I have corresponded with them about this), including analysis of the RATE diamond studies, full article open access at https://www.asa3.org/ASA/PSCF/2018/PSCF6-18Davidson.pdf and my own commentary at https://paulbraterman.wordpress.com/2018/07/07/can-we-trust-radiocarbon-dating/

  41. @PaulBraterman
    There are also ice core data, from several places around the Earth: Antarctica, Greenland, and scattered glaciers, which go back considerably beyond the limits of a Young Earth.
    As you say, there is a coordination of the results from widely different methods.

  42. @TomS, I also wonder why creationists keep on quoting apparent ages that are up to 10 times the maximum that their model allows. It is easy to see how apparent ages could be less than true ages, because of modern contamination, but there is no way in which the apparent ages could be more than the true ages unless the rate of production of carbon-14 was much less than it is at present, which would only be possible if the whole of cosmology was different before the Flood.

  43. @Paul Braterman
    I think that the idea is to show that evolutionism is based on false premises, and thus YEC is true.
    Of course, showing merely that there is a difficulty in a theory is not enough to show that an alternative is correct. (Ignoring for the moment that there is no alternative explanation for the variety of life.)
    For example, it has been known for a long time that there are severe difficulties in assigning the whole of the Pentateuch to Moses, but it took considerable work to come up with an acceptable alternative theory, the Documentary Hyppthesis, a theory which accounts for all of the difficulties in a comprehesive explanation. And the DH is subject to severe criticism, for all that. That’s the way that real scholarship works. It is not enough to find a difficulty in a working theory.

  44. @TomS: Indeed. And the DH is a very good analogy, with drastic revisions, modifications, and elaborations, and now looking at texts on a much finer scale than the originators

  45. I would be interested in finding out whether “revolutions” in disciplines other than science follow the same pattern.
    ISTM that politics is different. One can overthrow the old regime wihtut having a better idea. Indeed, “down with the king” may be enough, with no idea for what follows. (Isn’;t that what is playing out in the UK, right now? Leave the EU, and nobody knows what that entails.)

  46. Michael Fugate

    Armitage never claimed the fossil was 4000 years old in print – why? Because he has no evidence for it being that young. He has no evidence that it was unfossilized either. He avoided tests that would falsify his beliefs.
    https://www.nature.com/news/university-sued-after-firing-creationist-fossil-hunter-1.16281

  47. @TomS, agreed again. Scientific “revolution” is a metaphor, since a revolution is the more or less sudden removal of a government from power, whereas power is not so strongly localised in science.

    It is normal for scientific theories to endure despite anomalies, and according to Lakatos they are only displaced when a better alternative comes along. However, it is perfectly possible for a political power structure to be smashed when there is no replacement available. Brexit is a good example; it is utterly unclear what structure of governance will replace the nexus of treaties and joint organisations that hitherto have regulated the alignment between UK and EU law and commerce.

    It is very unusual for a political revolution to lead directly to successful replacement of the old power structure, because that old power structure only became vulnerable as the result of underlying problems that the immediate replacement may not be well equipped to address. In the case of Brexit, xenophobia, an unrealistic view of the U.K.’s importance, and the severe weakening of both the main parties.