What caused the Cambrian explosion?

June 20, 2013 • 5:14 am

The “Cambrian explosion” marked the rapid appearance of many animal phyla that persist today, and began about 570 million years ago (mya). Life itself appeared in the fossil record as simple cyanobacteria—”blue green algae”—about 3.6 billion years ago (bya); the first “true” cell with a nucleus probably arose about 2 bya; and the first multicellular organism between 1 and 2 bya.

The “explosion”, contrary to some creationists, wasn’t instantaneous, so it couldn’t have marked a single creation “event” at one time. Rather, the origination of many (but not all) modern phyla occurred between 570 and 540 mya. So the “explosion” took at least thirty million years.

Still, the reason why life lingered so long in a rather simple form, and then rapidly diversified into multifarious and complex forms, has been a long-standing puzzle in paleobiology. As I said, it can’t be due to an instantaneous creation, but intelligent-design advocate Stephen Meyer has a new book coming out that will claim that this rapid appearance reflects the action of the Christian God an unknown intelligent designer.  It’s likely to float yet another god-of-the gaps argument, but I’ll leave the assessment of its validity to the professional paleontologists who will undoubtedly review Meyer’s book. (Note to the DI, which loves to quote-mine me: my characterization of the Cambrian explosion as a “puzzle” does not mean that I think a naturalistic explanation will always elude our understanding, or that I give IDiots any credibility in your previous explanations involving a designer.)

Anyway, real scientists are at work on the problem, and have proposed many non-goddy solutions, including the accumulation of sufficient oxygen to allow the diversification of complex life, the advent of “toolkit genes”, like Hox genes, that could be coopted to build different body plans, the availability of empty niche space after the Ediacaran fauna went extinct, “arms races” between newly evolved predators and prey that drove things like the development of armor, and so on. Wikipedia has a list of competing explanations, and of course some could have acted in concert.

And new explanations continue to arise. One, proposed by geologists Robert Gaines and Shanan Peters, was just published as a short note in New Scientist, which, sadly, is behind a paywall. But I can summarize it briefly.

Being geologists, Gaines’ and Peters’ (G&P’s) hypothesis is geological, and rests on the observation that the geological strata reveal a huge section of missing rock, called the “Great Unconformity,” that may represent a billion lost years of Earth’s history.

G&P suggest that it is the weathering of this crystalline rock layer that gave the impetus to the Cambrian explosion. This erosion is likely to have filled the oceans with mienerals: calcium, magnesium, silicon dioxide, phosphates, and bicarbonates.

Eventually the accumulation of these minerals in the ocean might have permitted the already-present but simple life forms to cross the threshold of biomineralization: the incorporation of environmental elements into hard parts like shells, exoskeletons, bones, and teeth. It’s costly to make these parts, since it involves the use of metabolic pathways that can divert energy from reproduction, and perhaps the absence of minerals before the Great Weathering would have prohibited the evolution of hard parts. But the sudden influx of these compounds could have made the evolution of biochemical pathways for mineralization feasible, and their acquisition advantageous. Hard parts, like shells and exoskeletons, are useful in many ways: protecting you from the environment or predators, providing support, allowing larger body size, and so on.

As the authors note,

We suspect that the elevated concentration of ions in seawater effectively lowered the evolutionary barrier for biomineralisation. Today, most organisms invest energy in creating biominerals because hard body parts are so ecologically and evolutionarily advantageous. But evolution couldn’t “forsesee” how useful biominerals would be when shape into the teeth, claws, and shells we know today. [JAC: I’m not clear why the preceding sentence is in there. Clearly hard parts couldn’t evolve before the requisite minerals were available.] Instead, we think the ion influx promoted by the last stages in the formation of the Great Unconformity may have lowered the energy barrier to biomineralisation or caused biominerals to appear as metabolic byproducts. The usefulness of these new raw materials meant that natural selection could quickly take over.

Well, there you have it. I’m not a paleobiologist, so I can’t judge whether this explanation is a good one, or is contradicted by other observations.  Professionals in the area will undoubtedly weigh in. But one thing is for sure: if we’re going to have a satisfying explanation of the Cambrian explosion, it’s going to be a scientific one—one that is testable and does not invoke the action of the Christian God an intelligent designer.  Saying that “an intelligent designer did it” is the equivalent of saying “Sam did it.” It’s a non-answer, and yet another attempt to plug the gaps in our knowledge with God an intelligent designer.

137 thoughts on “What caused the Cambrian explosion?

  1. We seem to have an embarrassment of possible explanations for the relatively rapid development seen in the Cambrian, which is a long way from having no explanation.

  2. Question: Was it just animal phyla that underwent this explosion at the time? I would have expected marine plant life to “keep up”, but not be so evident in the fossil record maybe? I have this layman’s idea that most plants were minuscule & free floating algae “thingies” ~ difficult to find in fossil form…

    Also. At that time was the only non-marine life moss-on-rocks-type-stuff?

    Any info about plants at the time [links] would be great

    1. There were no land plants at the time of the Cambrian explosion. The oldest land plants we know about come from the Ordovician.

      It’s thought that land plants evolved from green algae. As far as multicellular algae go, I think they all fall into three groups, green, brown and red algae. I don’t know when these three groups originally appear in the fossil record but I seem to recall that they all evolved multicellular forms independently. My information is a bit dated, though, so if anyone knows better than me, please chime in.

      1. Plants have their own explosive radiation ~130MYA with the advent of angiosperms (diverging to ~135,000 species when mammals which arose at the same time have only got to ~5400), described by Darwin as ‘an abominable mystery’, but it is now much better understood than the Cambrian explosion. The accepted explanation is a concert of huge speciating pressure by pollinator interactions and rapid generation of polypoidy (gene doubling frees genes from conservation selection, so allows them to rapidly subfunctionalize (ie Hox/Wox) or gain novel functions, and the new plant often cannot backcross to the parent, driving a founder effect). Paelopolypoidy predicts >30% of plant speciation events are preceded by whole genome duplication.

        As for algae, green/red/brown is phylogeny for the endosymbiont, and pretty controversial at times.
        From a primary endosymbiosis event, 3 phyla of algae diverged – the Glaucophyta, the Rhodophyta (red) and the Chlorophyta (green, land plants).

        These were followed by secondary and tertiary endosymbiosis events, that spread chloroplasts across the eukaryotic tree of life. Brown algae are those whose nuclear genomes contain both green and red chloroplastic genes, suggesting they once had a secondary green chloroplast, which was then replaced by a secondary red. Macroalgae (multicellular) have arisen in the primary greens (plants and Volvox species) and the seaweeds (which are utterly unrelated, in secondary red and brown lineages).

        Today, 5 of the 6 eukaryotic supergroups (Amoebozoa, Excavata, Archaeplastida, SAR clade, CCTH clade) have some or all of their members bearing plastids (some, like Apicomplexan and Oomyctetes, have red plastids that have lost photosynthetic function).

        Only the Opisthokonta (animals, fungi, sponges, bunch of unicellular stuff) have never gained platids, although many of these have algae symbionts (lichin, coral, some sea slugs etc)

        1. Probably should have mentioned that Archaeplastida is the primary endosymbiont group (Glaucophyta, Rhodophyta and Chlorophyta)

          Also, things that get me incredibly excited:
          Paulinella chromatophora. Its a single celled organism outside Archaeplastidia that has undergone a very recent primary photosymbiont endosymbiosis event (only the second one ever known).

  3. I just finished “the Cambrian Explosion” by Erwin and Valentine. It goes into fantastic detail regarding the numerous possible causes of the phyla level increase- ecological, genetic, geological, meteorological, chemical (and more!)causes are all laid out and discussed in depth. Excellent read!
    Maybe we could send a copy to Meyer?

    1. I am reading it at the moment and they place the Cambrian Explosion from 530MA to 520MA; page 5).

        1. Well someone could go ahead an accuse me of that but I’d ask where the evidence is for it. I’m willing to accept evidence and change what I accept based on new evidence. The DI crowd are not as demonstrated by their rejection of the overwhelming evidence for evolution.

          1. You can accuse the believer in a Creator of being not objective, but I have met many evolutionists who are closed in their thinking to this explanation for life. Creation has to be a rational alternative to the philosophy of evolution, but many are closed to this position. Darwin was concerned with the fossil evidence or lack of fossil intermediates as a weakness in his theory. I am with Darwin on this one as there is an extreme lack of intermediates and redundant forms.

          2. there is an extreme lack of intermediates and redundant forms.

            And your authority on this is who? Ken Ham? Have you read Coyne’s book? Of course not. Come back when you have.

          3. Creation has to be a rational alternative to the philosophy of evolution, but many are closed to this position. Darwin was concerned with the fossil evidence or lack of fossil intermediates as a weakness in his theory.

            You need to do some reading up on the following: definition of evolution, definition of philosophy, the intermediates (lots and lots) in the fossil record.

            When you’ve refreshed your knowledge, you can come back and chat some more.

        2. Also you should try harder for mocking me in using “god goggles”. It would have been more creative to say “atheist spectacles” for instance.

          1. Evolution and creation are both unprovable metaphysical beliefs; suggest otherwise is a category error. If you don’t want to.discuss the ethical and practical implications lets call.the whole thing off .

          2. I have to part from my usual practice of not insulting readers to tell you that you’re not only a jackass, but an ignorant jackass. In fact, to use the term for you is an insult to jackasses. I have written a book with the scientific evidence for evolution. Evolution is by far the best explanation we have for the diversity and change over time of life. (Nothing. Herr Esel, is absolutely “proved” in science, or didn’t you know that, either?) But where is a book giving convincing evidence for creationism? The Bible? Nope. Intelligent Design? Nope, it was rule as “not science” by Judge Jones and the community of working scientists..

            So, Monsieur Âne, I suggest you go over to the websites for ignorant equids, of which there are many. But this is one of them, and I won’t have ignorance like your splattered all over the pages of a serious website.

  4. That the Cambrian Explosion reflects the origin of “hard parts” is a long-standing hypothesis. There are several variants: 1) the various phyla had been around for awhile, but hard parts make them fossilizable, hence visible; 2) hard parts evolved around then, which stimulated lots of evolution; 3) the origin of hard parts led to an “arms race” between predators and prey. These are not necessarily all mutually exclusive.

    I don’t know the literature well enough to know where Gaines and Peter’ idea fits in, but it seems to be an elaboration of 2.

    1. Thanks very much for the first link Thomas. Took me some time to read it all, but worth it.

      Very interesting. I had no idea!

      Things I took away:-
      ** inhabited terrestrial environments by the Paleoarchean

      ** land-basod life could have been pivotal for early oxygenation of atmosphere

      ** idea that land first colonised by plants should be abandoned

  5. The primary paper by Gaines and Peters was published in Nature in 2012. Gaines is at Pomona College and they have a simple summary on their site. As with many other evolutionary phenomena, there is likely no single explanation. However, the DI/ID and other creationists operate by establishing a false dichotomy and claiming that “weaknesses” in evolutionary hypotheses support their explanation.

  6. Mineralized structures didn’t occur just because calcium became readily available – mechanisms for deposition of calcium phosphate had to arise. I don’t know if any of the books on this go into the mechanisms, but suspect that they don’t because the reader would a) need some background in biochemistry and b) AFAIK it’s still poorly understood.

    I read a paper years ago in J Biol Chem (Marsh, 1977) that I used in a journal club, about development of the shell in some mollusc. The sense was that a protein segment with an array of serine residues lines up with a segment with an array of histidine residues. The serines become phosphorylated and ion-pair with calcium. The imidazole ring of the adjacent histidine attacks the serine, forming a crosslinked residue, histidinoalanine, releasing insoluble calcium phosphate (hydroxyapatite) in a layer dictated by the presence of the protein, which then degrades, leaving the hydroxyapatite in a place dictated by where the protein was.

    Surely, a protein like that didn’t arise in present form back then, but once a rudimentary form had appeared, it could be refined in the usual way through rare advantageous gene duplications / internal segment duplications along with point mutations. Each time one of those rare events happened, it seems easy to envision a quantum step forward in enabling greater complexity.

    From occasionally touching base with this area in subsequent years & as said, my sense is that the exact process of mineralization is still poorly-understood, but a search using histidinoalanine turns up references to its presence in developing teeth, too.

    1. I’ve done research in biomimetic mineralization, using synthetic polymers to imitate proteins as the matrix. All polymers induce mineralization, and matching the polymer’s various chemical groups to the ions to be mineralized results in more and more perfect crystallization.

      So, any ordinary, already-present protein could start mineralizing an amorphous mineral layer (actually, amorphous layers form wholly on the top, outside of the matrix, a primitive outer skeleton). Then harder, more perfect, better aligned, more spatially oriented,crystalline layers would form as the protein evolved ever-better binding sites.

      Being that I’ve done research in this area, I of course love this explosion hypothesis, since I can claim to have contributed a tiny amount of data that supports it!

      1. And this illustrates how sad pseudoscience really is. The pseudoscientists take advantage of ‘the stars of science’ and that somehow everything fits in one book. When, instead, we have Garnetstar and so on, filling in little but important details: I had never heard of anyone working specifically on “biomimetic mineralization” until now – and yet it seems obvious in retrospect.

        Shorter; Science is bigger and more comprehensive than even us “supporters” sometimes think consciously.

        1. Wow, thanks guys, I’m blushing.

          Studying and imitating biomineralization became hot when chemists realized that biomineralized arrays had so many outstanding properties. Biomineralized crystals are often perfectly uniform in size, structure of the mineral, morphology, spatial distribution, and even orientation of crystallographic axes. Those are essential features for using nanocrystalline arrays of lots of high-tech minerals, such as those that have “non-linear” optical properties, which could be used for super-fast computers.

          But, alas, Nature is a much better chemist than any human*, and we can’t yet create such organized assemblies. So, lots of study of biological mechanisms and trying to apply those principles to synthetic systems.

          BTW, calcium carbonate is the major mineral in sea-creatures shells and skeletons. Carbonate is formed when atomospheric CO2 dissolves in water, so enough of that would have to happen to get to a high enough level of carbonate to start mineralization.

          *I know of only one case in which a human chemist devised and analogue to a naturally-occuring reaction before the natural process was discovered: Charles Goodyear found that sulfur crosslinks polymers (“vulcanizing” rubber and making it strong enough to use as tires) before it was found that that’s how living systems cross-link proteins.

          1. Cool that there’s someone on here that’s actually worked in the biomineralization area.

            And as a sidebar to your sidebar, it was noticed in the 1930’s that rubber industry workers became ill after drinking modest amounts of alcohol if they had been using a certain sulfur-containing compound, tetraethylthiuram disulfide, in the vulcanization process. Tradenamed Antabuse, that compound is still used to some extent in aversion therapy for alcoholism.

  7. You can take any number of ‘what happened’ scientific theories and lump them together and prove the lot. It still gives no real explanation. Ultimately, the how of the beginning and the why of the progression still eludes one – because the only feasible explanation must be an intelligent driving force – equally ‘scientific’ in essence. ‘Spontaneous’ and ‘inherent’ doesn’t cut the mustard, because the question still arises on where this happy spontaneity or inherent quality came from, and what motivates the ongoing progressive drive in everything.
    Then one comes to the amusing and irrational knee-jerk aversion to anything that might remotely resemble the ‘god of the gap’. Intelligence arising from intelligence would seem a lot more likely than that it arrived, blinking in bewilderment, out of nothing or out of one inert quality, substance or force. Thus, as a theory requiring verification, this is surely a massive step better than no theory at all.

    1. because the only feasible explanation must be an intelligent driving force

      I think you’ve missed out a LOT of steps here. Perhaps you could try to expand out this specific claim into, you know, an actual demonstration of it’s truth/likelyhood?

      because the question still arises on where this happy spontaneity or inherent quality came from, and what motivates the ongoing progressive drive in everything.

      More work here as well – claiming “motivation” implies an agent, which seems to me is what you’re arguing for. You shouldn’t start arguing FROM your conclusion.

      Intelligence arising from intelligence would seem a lot more likely than that it arrived, blinking in bewilderment, out of nothing or out of one inert quality, substance or force.

      And yet for this to be more likely we’d need to demonstrate that this prior intelligence actually exists – ID tries to do this and fails.

      Thus, as a theory requiring verification, this is surely a massive step better than no theory at all.

      When the theory (really, hypothesis) your expounding has little to no evidence, and requires some pretty massive ad-hoc ancillary assumptions to even get off the ground, perhaps no theory is better.
      After all, it’s ok to say “I don’t know”.

      1. 1 You have other feasible explanations for that aspect? Wow, do tell!

        2 I am arguing on observable fact. Living things show motivation in their behaviour – with the intelligence or sophistication of those manifestations graded according to type of organism. Intelligence and complexity are observably on an upward spiral (hmm – with human beings, one sometimes wonders …).

        3 Let’s get this down to basics. Stephen says that everything began with an inherent quality in what there was at the time – just the force of gravity? – and that this inherent quality started things going with the Big Bang and Evolution et al. This hardly escapes from the shortcomings of the ‘spontaneous’ theory. Is there really such a thing as complete spontaneity, in fact? It is actually a response to something, whether action or creation of the right conditions.
        Therefore the hypothesis (you are right; that is a more accurate term) which fits better is that intelligence came into the starting mix. This is strengthened by seeing evolution continuing in ways which seem to go far beyond automatic responses to stimuli – look at the field of virology, for example.
        Whether the intelligence was already part of the mix (intelligent universe) or an external aspect (god) is still in the field of mere speculation, but one or the other can still be adopted as a hypothesis for further examination.

        4 It is OK to say, ‘I don’t know’ and leave it there?
        Newton sees an apple fall, wonders why, and leaves it at ‘I don’t know’. Knowledge stays static. Instead he comes to the conclusion that there is a natural law involving a force. Everyone laughs and responds, ‘Force? Nonsense; apples fall just bacause that’s the way things are.’

        Why is it that so many ‘respected’ scientists will on the one hand enthuse about the complexities of the universe, but on the other go to desperate measures to deny that it is, in itself, demonstrating intelligence?

          1. That is an excellent point. There has to be a start somewhere. Something simply was, always has been, and always will be – after all, time is relative. On a choice between matter (at any frequency) and intelligence, the latter seems more likely.

          2. I think you missed out a LOT of steps here. Perhaps you could try to expand out this specific claim into, you know, an actual demonstration of it’s truth/likelihood?

            First, you don’t explain what the first intelligence comes from.

            Second, you suddenly break the chain of increased complexity. And note, that all of physics sees _decreased_ complexity as we go backward in time. The prediction is that structure formation, which was induced by quantum fluctuations in the inflaton field, will maximize complexity just about now. Later dark energy will dilute the matter content of the universe, and it will die of heat death. This is standard cosmology.

            This is why we know a “first intelligence” is utterly unlikely, as opposed to simplicity evolving into complexity and intelligence.

            Third, when was all time relative? Local time is absolute, see relativity theory, or we wouldn’t have other frames as relative.

            Also, “matter (at any frequency)” doesn’t make sense.

          3. You don’t and can’t explain where the first matter came from – however far back you may take that process. As I say, one has to start somewhere.

            For the questions on time and matter, one has to look at quantum theories and their modifications on standard relativity, inter alia. And, no, I am not going scratching for citations. You want ’em; you get ’em. However there seems to be compelling evidence accumulating that everything consists of the same thing; which, confusingly, is mainly made up of emptiness (this part is WAY beyond me) but on different frequencies. Energy, light, lead, gold, protein, DNA – you name it.
            Evolving of itself without some ongoing drive is hard to accept. What you mention are observed, theorised, or hypothecated tendencies, but the core for the complexity must already be present as potential. Also, for ‘intelligence’ to exist is not necessarily dependant upon the flow of electronic current in an organic or mechanical ‘brain’.

          4. The first matter is inflationary standard cosmology:

            “In the most common models the Universe was filled homogeneously and isotropically with an incredibly high energy density and huge temperatures and pressures and was very rapidly expanding and cooling. Approximately 10−37 seconds into the expansion, a phase transition caused a cosmic inflation, during which the Universe grew exponentially.[24] After inflation stopped, the Universe consisted of a quark–gluon plasma, as well as all other elementary particles.[25]” [ http://en.wikipedia.org/wiki/Big_Bang ]

            I.e. the potential energy of the inflaton field was converted into heat, and so particles. If that description confuses you, look up Susskind’s youtube lecture on cosmology.

            “For the questions on time and matter, one has to look at quantum theories and their modifications on standard relativity, inter alia.”

            You know what, now you are just babbling. “Standard relativity”, and what would the 80 year old quantum theory modified by special relativity aka quantum field theory say on time? (It says a lot on particles, and why heat makes them after inflation stopped.)

            You have a lot of catching up to do. Start with today’s cosmology and Susskind’s lectures on it from this year.

            “Evolving of itself without some ongoing drive is hard to accept.”

            You miss the point, the evolutionary processes are well known and well studied. And not only are they satisfying studies, we have no working alternative.

            “Also, for ‘intelligence’ to exist is not necessarily dependant upon the flow of electronic current in an organic or mechanical ‘brain’.”

            Electronics is chemistry of sorts, ask a battery.

            We now know from LHC, beyond reasonable doubt, that it is necessary with a physical template (if there were any doubt), and that the template mechanics is all what goes into a mind (if there were any doubt). (See my other comment.) It is scientific knowledge, a result of modern science.

          5. There has to be a start somewhere. Something simply was, always has been, and always will be

            You do realize you just contradicted yourself in the space of two adjacent sentences, right?

          6. No, the start was the universe as we know it – or are trying to know it! 🙂
            Whatever it began from is the permanent bit. Show me how nothing can become something in a somewhere that was nowhere, and I will be deeply impressed.

          7. the start was the universe as we know it – or are trying to know it!
            Whatever it began from is the permanent bit

            And where did that bit come from?

          8. Tules, it was always there.

            Oh, it also happens to be intelligent, can perform magic tricks, and cares whether you’ve been good or bad.

            But it was always there! 🙂

        1. 1. It doesn’t matter whether I do or not – you’ve simply asserted your answer as true without any attempt to justify it. To think that doing this makes your case is just silly.

          2. This actually argues against your point about a prior requirement for inteliigence – it exists on a continuum, so there is no need to posit some “miraculous” event to explain it.

          3. Are you now retreating to a “fine-tuning of the universe” argument? Again you’re simply inserting your preferred conclusion into your hypothesis without bothering to support it. I agree that intelligence (within or without the universe) could be a part of an hypothesis. In fact, they have been. And they’ve failed simply because they tend to explain everything (the God hypothesis is horrible in this regard) and they tend to completely lack reasons to suppose the starting assumptions should be adopted (the universe shows no “inherent intelligence” and there is no good reason to suppose God exists, and very good reasons to suppose it does not).

          4. Did I say to leave it there? You want to change a state of (your own) ignorance into a positive claim – that God did it. Far better of you to say YOU don’t know, especially as you seem to take ID seriously (which tends to betray an ignorance of the current state of scientific knowledge).

          I didn’t see any additional working out of your claims in this second comment – just more or the same.
          Perhaps in your next comment you could try to provide reasons to think your claims are true? 🙂

          1. You are attributing ‘assertions’ to me which were not made. My stance is that other possibilities exist and that science and atheism do not necessarily go hand in hand. The arguments against intelligence in the intial mix remain unconvincing, intellectually and intuitively. There would be nothing ‘miraculous’ about such intelligence – it would simply be part and parcel of all that is.
            Intelligence may appear to be on a continuum, but without a basis of it to start off with, disconuity rules.
            What ‘claims’, for Pete’s sake?
            Let us please not confuse scientific opinion with scientific knowledge. Note the speed with which accepted scientific theory is constantly upset and replaced.
            Your assertion that the universe shows no inherent intelligence is incomprehensible. The whole design, from the cosmos down to smallest organisms, displays intelligence in design, operation, and adaptation.

          2. The whole design, from the cosmos down to smallest organisms, displays intelligence in design, operation, and adaptation.

            Because nothing says “intelligence” like a billion billion cubic light years of vacuum at 2.7K.

          3. Is that vacuum absolute?
            Yes, to any reasonable level of precision (on average, there is about three hydrogen atoms per cubic metre).

            Again, how it is “intelligent” to produce so much freezing emptiness?

          4. Okay, let us get down to scientific knowledge.

            – We know since the last half year, independently from WMAP 9 year and from Planck 1st data release, that the universe as such and its structure content were a result of spontaneous processes. (As your “Stephen” (Hawking?) is claimed to say.)

            Inflation is the consensus so far. And both the universe ended up in a big bang at an indeterminate time as inflation ended and its structure formation was due to spontaneous quantum fluctuations in the inflaton field seeding the density variation that later formed galaxies.

            How do we know this? Because a livable universe have to be nearly perfectly flat to form structures (too open, and galaxies wouldn’t form as the universe expands too rapidly) at habitable time scales (too closed, and galaxies would be too short-lived as the universe crunches back on itself). And inflation is the only way to form structures in a flat universe.

            In fact, seeing how not only our standard cosmology but all cosmologies we know how to work, Friedman cosmologies, need homogeneity (so large enough to form habitable structures) and causality (so persistent enough to form habitable structures), we can only conclude one thing:

            Either we have physics and a universe. Or we have magic and no universe.

            In retrospect, magic was not only a terrible idea. It was the worst among terrible ideas ever invented.

            – We also know that LHC finalized, in some form or other, the standard particle model with the observation of the Higgs field. That means the laws underlying physics of everyday life are completely understood.

            “Not sure why people don’t make a bigger deal out of this fact.”

            “A hundred years ago it would have been easy to ask a basic question to which physics couldn’t provide a satisfying answer. “What keeps this table from collapsing?” “Why are there different elements?” “What kind of signal travels from the brain to your muscles?” But now we understand all that stuff. (Again, not the detailed way in which everything plays out, but the underlying principles.)

            Fifty years ago we more or less had it figured out, depending on how picky you want to be about the nuclear forces. But there’s no question that the human goal of figuring out the basic rules by which the easily observable world works was one that was achieved once and for all in the twentieth century.”

            “Constantly upset and replaced”, was it?

            It also means our everyday physics sector of biochemistry of a few eV is eminently protected against new physics up to 100’s of GeV. No upsetting that, no more.

            Now, particle physics vacuum has a funny physics. It turns out everything that isn’t explicitly forbidden will happen, i.e. will be a law. This means that since quantum field theory for electromagnetism (QED) predicts some observed interactions up to 11 significant digits, what hasn’t been seen by now won’t be seen beyond reasonable doubt.

            So if it isn’t a biological mechanism affecting biology, forget it. (Oh, we could still be affected by the haphazard high energy cosmic ray. But we look at everyday effects.) Specifically, we now know that astrobiology, non-biochemical “souls”, afterlife, rebirth, intercessory prayers, homeopathy, reiki et cetera are all bunkum.

            So not only didn’t, and couldn’t, the universe contain any magic from the beginning, it sure isn’t affecting us today from some sort of “gap”.

            Don’t be confused by hallucinations of “design”, apparent design has for centuries been known to result from physical, chemical and biological evolution – simple processes.

          5. Actually, this deserves a longer comment.

            While science doesn’t know everything (cue Dara Ó Briain), what is not widely understood, but deserves to be, is what science knows cannot be, as Sean Caroll described in his Skepticon V talk, which, among other things, you précised above.

            /@

          6. ‘Spontaneous’ in the sense that each was something which would happen automatically given certain conditions, rather that that they would simply happen? That is a misuse of the word, actually.
            In all of these things, physics tells us firstly that something works and secondly under what conditions it works, and laws are formulated and refined to define the working. It still tends to get very sketchy on many aspects of how it works, and pretty dismal on why it works.
            Most of these ‘laws’ cover something which can be regarded as ‘magic’, as would most modern inventions not that long ago. Having formulated the ‘laws’, though, they are then used as fundamental explanations for what is happening – like saying water will boil at a certain temperature at a certain altitude but making no attempt to find out the chemistry of why and how that begins the process of changing state.
            You ‘know’ that things like the ones listed are ‘all bunkum’ because they are not consistent, or fail to manifest, in response to scientific testing. Then, numerous individual cases in support (eg homeopathy) are ignored, or other explanations are sought – which may be the correct ones, of course. The point is that while any significant data exists to support any one of them, you do not ‘know’ and they aren’t necessarily ‘bunkum’.
            That is being as dogmatic and closed to reason as the most fundamental religionist.
            The facts of design in evolution are, in themselves, miracles. The processes are rarely simple, nor do they seem to be understood anywhere nearly to the extent the scientific world thinks they are. Unless I look up all the wrong references.

          7. … like saying water will boil at a certain temperature at a certain altitude but making no attempt to find out the chemistry of why and how that begins the process of changing state.

            Um… that’s not chemistry.

            Maybe you should refrain from commenting on profound matters until you’ve properly grasped high-school science.

            /@

          8. You are attributing ‘assertions’ to me which were not made. My stance is that other possibilities exist and that science and atheism do not necessarily go hand in hand.

            Actually, you asserted that there must be an intelligence.
            You also asserted that intelligence came from intelligence as being a more likely possibility.

            Are you now backing away from these claims (claims which you’ve failed to back up)?

            The arguments against intelligence in the intial mix remain unconvincing, intellectually and intuitively.

            And the arguments for there being an intelligence in the initial mix are completely superfluous and implausible, with no evidence to support them. I’ll take unintuitive with evidence thanks.

            There would be nothing ‘miraculous’ about such intelligence – it would simply be part and parcel of all that is.

            And?
            Simply defining something as being “part and parcel of all that is” doesn’t mean it remotely probable, or that you’ve got evidence to support such a claim.

            Intelligence may appear to be on a continuum, but without a basis of it to start off with, disconuity rules.

            Well, we have things like bacteria which display what looks like “motivation”, which is nothing more than very complex organic chemistry. That’s the bottom of your continuum of intelligence.
            And we have examples of simpler organic chemistry, so we have a continuum of that.
            Are you arguing that chenmistry display motivation too?

            Your assertion that the universe shows no inherent intelligence is incomprehensible.

            The fact that NONE of the established scientific findings make reference to ANY inherent intelligence in the universe appears to blow this statement out of the water.
            Perhaps you’d care to demonstrate your point instead?

            The whole design, from the cosmos down to smallest organisms, displays intelligence in design, operation, and adaptation.

            You asked me what claims – this is one, for a start.
            Asserted without any attempt at justification on your part.

          9. The standpoints are streets apart, apparently. Your thought processes are also complex organic chemistry, but you would class them as intelligence. It seems that science cannot see the wood for the trees in this direction. What sort of behaviour, other than what is currently shown, would sceince regard as intelligent? The more we learn about the universe, the more it seems QED that it has such qualities – so far beyond ours that this is perhaps why they are ignored.

          10. You are attributing ‘assertions’ to me which were not made. My stance is that other possibilities exist and that science and atheism do not necessarily go hand in hand.

            I’m not sure where anyone has suggested that atheism is NECESSARY for science, or vice versa.
            Scientific findings just happen to SUPPORT a conclusion of atheism. It didn’t have to be that way. And if your claims regarding intelligence were actually supported by the evidence, it would not be that way (Theism or Pantheism would be conclusions supported by the evidence).

          11. >>The whole design, from the cosmos down to smallest organisms, displays intelligence in design, operation, and adaptation.

            1) There is intelligence all right, but it’s in the humans looking at the Universe. Intelligence is a property of a behavior of a mind. When you attribute it to inanimate objects and smallest organisms with no brain, you are using the word as a figure of speech.

            2) And in any case, when you look at Nature you are closing your eyes to the dumb and ugly parts of it, that’s why it looks beautiful and smart. Over 99.99% of all species have gone extinct. 1 billion years of life with nothing more than bacteria. Great voids of space in Universe. The prostate gland surrounds the urethra. Human history laced with slavery, witch burnings, human sacrifices to imaginary, genital mutilations, poverty, hunger, war.

            A non-selective look at the real history of life or the universe shows not intelligence, but a bumbling trial and error process hugely wasteful of time and material.

        2. colonialist claimed

          You don’t and can’t explain where the first matter came from – however far back you may take that process. As I say, one has to start somewhere.

          See Lawrence Krauss’s A Universe From Nothing for some ideas on where to start based on actual physics rather than wishful thinking.

    2. Ultimately, the how of the beginning and the why of the progression still eludes one…

      The how – no it doesn’t elude one and there is a lot of evidence for “how” and the “why” is irrelevant. If you are implying agency with “why”, you have a lot of a priori assumptions built into that “why”. If you are really asking this without implied agent then this is just another way of asking “how” so go back to my point at the start.

      1. The evidence for the ‘how’ still doesn’t go back far enough. The ‘why’ is of paramount importance. Why the progression?. Why not remain whatever there was to start? These are valid questions for any probing mind which is not content with ‘that’s how it is’ answers.
        The implied agent, internal or external, seems a way to take possibilities a step further instead of at the brick wall otherwise reached.

        1. Why not remain whatever there was to start?

          Perhaps you ought to read up on it – the answer is there for you (hint: imperfect replication).

          The implied agent, internal or external, seems a way to take possibilities a step further instead of at the brick wall otherwise reached.

          Except of course there’s no good reason to think that this implied agent exists, and postulating it doesn’t actually provide you with a more successful explanation.
          Perhaps you could try doing something about those gaping holes in your own hypothesis before claiming it’s superiority?

          1. In essence, the current scientific answer boils down to the universe starting because it went bang and bits of it went flying off in all directions, which caused other bits to start groping around to acquire more and more complex natures. All of it all accidental-like and then because of loads of ‘natural laws’ coming into being.
            I think I’d rather go for the Tooth Fairy.

          2. I think you may not have a firm grasp on the Big Bang and your conflating a lot of different things all at once – are we talking about the Big Bang or evolution?

            Before dismissing scientific facts (yes facts, proven facts) you may want to ensure you firmly grasp those things first. People on this site can answer questions and point you to resources but you have to do some of the work to understand.

            You need to understand as well that asserting claims like “god did it” means the onus is on you to prove those claims.

          3. No claims have been asserted. The hypothesis has been put forward that in the very beginnings of the universe, an intelligence was in evidence to set the process in motion, on the grounds that an intelligence is capable of such behaviour whereas it seems doubtful that anything inert could have been.

          4. colonialist, your “hypothesis” is full of claims.

            Your entire thing hangs on the claim that there is some external or inherent intelligence to the uuniverse. This has neither been demonstrated nor has the usefulness of this claim been shown.

            You’ve also claimed that intelligence begetting intelligence is more probable/plausible/likely, but have not shown this to be the case.

          5. “an intelligence was in evidence” – what evidence do you have for this intelligence and will you test your “hypothesis”.

          6. Oh, the irony!

            – That is out of date.

            First, the inflationary standard model starts with inflation. Here the inflating system descends, likely with fits up and down from quantum fluctuations (spontaneous, remember), a flat slope of a huge inflation field potential in a viscous manner. I.e. it is slowly falling at terminal velocity.

            When parts of it falls off the steep cliff of the potential, it ends up at low potential (current low vacuum energy) but a lot of heat from the fall (from the inflaton potential energy). We know it doesn’t fall over all at once, or the density fluctuations that eventually makes galaxies wouldn’t occur. Fluctuations in the field caused that.

            That heat becomes big bang, as many cosmologists now like to define it. Nowadays you have to check what people mean with big bang.

            Second, the universe expands. There were never a time when particles moved comparatively fast to expansion so you can’t say “explosion”, “bits off it flying off”, at all. Matter was boringly stuck in the spacetime matrix, or rather moving relative each other at roughly galactic speeds.

            – We can have a long discussion how or even _if_ inflation had a start and why the system, or at least the part we see, was at the top of the potential. But that is another discussion.

            – As opposed to fairies, we see these things. Big bang is pretty much an observation from the microwave background alone, and all cosmologists accept it. And these things tell us they had effects. If you have an alternate theory, you must replace what is seen or nearly so, with something better.

            So far, you gave us the Ultimate Tooth Fairy.

          7. Whether the hyperinflation story is the next one in vogue or not is unimportant. When one goes back the the whole start of the process, from inertia, something had to set it going. This is where it ‘just happened’ does not seem very good thinking.
            Of course, another possiblility – that the universe is just one of an infinite number of them which are simply an ongoing process, would then remove the need for a starting agency. The nature of the multiverse or whatever would then need a different approach. Maybe universes happily swap virtual particles?

          8. Even *if* something started the Universe. Why would that something be intelligent?

            Start your argument from personal incredulity now.

    3. The spontaneous, inherent quality comes from the laws of chemistry. Thermodynamics and kinetics determine whether a reaction is spontaneously seen, how fast it happens, and to what extent it happens, under the specified conditions.

      Are you trying to deny that chemical reactions are spontaneous? If you breathe in cyanide gas, do you believe that a specific reaction, the one that has the best combination of thermodynamics and kinetics, will not occur?

      Do you think that when you supply an electrical spark to your car’s gas tank (i.e. start the car), that a chemical reaction, the optimum one, won’t occur between gasoline and oxygen? How about when you mix bleach and ammonia, or light a fireworks display?

      If you do think that chemical reactions are spontaneous and inherent, you are in big trouble. Don’t experiment with breathing cyanide or lighting a match in a gas-filled room. Learn some chemistry, before you kill yourself and others.

      1. Whoops. That’s “if you think that chemical reactions are NOT spontaneous and inherent…”

        And, just to add: the optimum reaction, its speed, and its extent, can be calculated for any particular reaction, from the basic laws of chemical thermodynamics and kinetics.

        1. ‘Spontaneous’ – OED – ‘Acting or done or occurring without external cause’.
          All the reactions you mention have external cause. They are not truly spontaneous in that they require the conditions to be met before they are in operation. Then they are responses to inherent qualities.

          1. The only necessary “external cause” is the existence of atoms. Once you have atoms, you have the laws of chemistry.

            Reactions occur in any and all conditions: changing conditions only changes which reactions will occur spontaneously, and to what extent, and how quickly. There are chemical reactions that occur in the extremely low concentrations and temperatures of space, and there are reactions that occur under any other conditions.

            That includes spontaneous formation of amino acids from even very inert gases (more inert that the Stanley mixture, the spontaneous assembly of proteins from amimo acids from salt-containing warm water solutions, and the spontaneous assembly of nucleotides from frozen solutions of inert inorganic simple molecules.

            Chemical reactions are spontaneous and self-directed and self-organizing. If there are atoms, there is chemistry.

          2. For a reaction to be truly spontaneous it has to happen without any change in condition or outside influence.
            If X is mixed with Y causing Z reaction, that reaction is a result not only of the properties of X and Y, but of the mixing, and the external cause is whatever placed them in proximity to one another.
            Spontaneity of the sort that seems to be envisaged by current theories for ‘the beginning’ would have to be like a man deciding, quite on the spur of the moment, to take a different route home – that is a spontaneous decision. So, this is back to saying, ‘It happened because it happened.’

          3. The spontaneity seems to be open to question – it seems that even the appearance of virtual particles in the vacuum can have plausible stimulators. Total spontaneity is unproven.

          4. Total spontaneity is unproven.

            Perhaps, but you’ve not shown that the universe (or, more accurately, our co-mocing patch) requires total spontenaity.
            You’ve asserted that it does, but not demonstrated it.
            Perhaps you could give that a try?

          5. would have to be like a man deciding, quite on the spur of the moment, to take a different route home – that is a spontaneous decision.

            Well, since that decision likely happened entirely in the man’s brain, you’ve just undermined your position.
            If a brain can display “spontenaity” and a brain is just a collection of matter, then why not the beginning of our co-moving patch?

          6. Huh? Atoms (and molecules) move around randomly, whether in liquids, gases, or even solids. The speed at which they move is determined solely by the temperature, but where they move is random.

            So we have atoms that have temperature, moving. They randomly bump into each other, how often (but not when or which atoms) being determined by a Boltzmann distribution. Then a chemical reaction occurs, which one being determined only by the laws of chemistry.

            How is that an “external cause” that “placed them in proximity to one another”?

            delta G = delta H – T(delta S).

            When you understand that, try posting again.

    4. because the only feasible explanation must be an intelligent driving force

      Why is that the only feasible explanation? Why is that even a compelling explanation?

      Intelligence arising from intelligence would seem a lot more likely than that it arrived, blinking in bewilderment, out of nothing or out of one inert quality, substance or force

      Why does it seem more likely to you?

    5. Intelligence arising from intelligence would seem a lot more likely than that it arrived, blinking in bewilderment, out of nothing

      And that first intelligence came from…?

          1. But that would mean that turtles that begat intelligences needed intelligences to beget them. It’s wheels within wheels.
            I’m so confused! 🙂

          1. That bit of a yolk in science actually does make sense. How disappointing. Now I have to find a convincing way of saying the same thing which is not as easily sabotaged by evolutionary logic. The hen or the cock? Eureka!

          2. Sorry, no.

            AS the PopSci article says, some proto-chicken laid an egg which resulted in a chicken.
            But these things don’t happen in isolation – there was a population of proto-chickens, from which chickens resulted – both hen and cock.

            So the answer to your question is “both” or “neither” 🙂

          3. Okay, colonialist, that’s enough comments out of you on this thread (16, I believe). You have evinced no evidence for an intelligence in the universe, and you’re relying on old, shopworn, and refuted theological arguments.

    6. Typical of IDers. Gaps in the fossil record–must prove god. Abundance in the fossil record–must prove god.

    7. “You can take any number of ‘what happened’ scientific theories and lump them together and prove the lot. It still gives no real explanation.”

      So gravitation isn’t a real explanation for dropped objects falling? I assume you are a proponent for “intelligent falling” then.

      Pro tip: Pointing to something, even as little as modern gaps in understanding, and go “magicdidit” doesn’t cut it. What predicts everything, predicts nothing – no constraints.

      1. I think gravity is usually called “Intelligent Sucking.”

        IMHO that’s very appropriate, since “intelligent sucking” is also a good description of the ID position and the entirety of its scholarly output.

  8. Can a simple physicist make a comment? I once attended a seminar in which all the details of a single ion-channel in a single cell were described in all their very complex detail. And the same basic mechanisms apply in one way or another to all cells, and are by no means the end of the enormous complexity of any single cell (biologists, please correct me!). And then it occurred to me that it was very plausible that life spent so long as single celled or even non-nuclear organisms. It just took that long to establish the complex mechanisms and systems that exist in every cell.

    1. Yep, you could probably liken it to building a head of steam in a locomotive (for a physical analogy). It takes a good while to bring things up to temperature, and it’s not just the water, there’s all that iron to heat up, too.

      And as long as I’ve mentioned steam engines, I can’t resist linking to a nice clip of my favorite one, in action, the exact replica of the 175y/o engine of the Eric Nordevall (which sank in 1856), that now powers the E Nordevall II as it plies the waters of the Göta Canal + interconnected lakes in Sweden.

        1. Glad you liked it! What’s more, the engine was built by the same foundry/works that built the original one. Poke around a bit, and you’ll find that the original sits virtually perfectly preserved on the bottom where it sank while under tow after running aground. That’s how all could be replicated in such detail.

  9. It’s actually quite irritating that an interesting article has to be so full of disclaimers about ID etc. It’s a shame you have to cater for the childish & wilfully ignorant.

    1. It’s less about catering to the IDiots than it is about heading off their entirely predictable quote-mining and misrepresentation. They scan any article about evolution (particularly if it’s by anyone even remotely well-known) for anything that can be (mis)construed to either cast doubt on evolutionary science or give apparent support to ID. It’s because they have such a history of craven dishonesty that Prof Coyne feels the need to qualify his remarks.

  10. You can read the first few chapters of Meyer’s Hopeless Monster 2 on the B&N site.

    True, indeed, he lays out a case for a god-of-the-gaps argument. The Cambrian biota had no ancestors (none found) even though conditions for fossilization were el perfecto.

    He even quotes the recent Valentine book, page 8, but true to Meyer’s lying, dishonest form he twists Valentine’s meaning 180-degrees in true quote-mine fashion.

    Meyer is neither ignorant nor stupid. He’s shamelessly dishonest. Meyer knows that the entire “thesis” of intelligent design creation rests on there being no ancestral lines prior to the Cambrian Explosion. It’s key to the entire charade. Meyer attacks phylogenetic trees in Chapter 2 where he writes “Darwin’s theory predicts gradual evolutionary change in contrast to the fossil evidence.

    That’s the ID creationism thesis in a nutshell. Gaps represent creation events.

  11. The problem I have with the G&P’s hypothesis is that it doesn’t predict the succession of found mineralized parts. Sponge spicules are the oldest though perhaps challenged finds from Doushantuo @ ~ 580 Ma bp. (Or even more arguably, the Namibian claims @ ~ 760 Ma bp.) This doesn’t seem predicted by a disappearing threshold energy cost of biomineralization as much as some more gradual process.

    I tentatively favor a recent hypothesis of the necessity of a nitrogen cycle, because it may have controlled ocean oxygen-poor conditions at the time:

    “… considers the composition of the oceans 550-700 million years ago and shows that oxygen-poor toxic conditions, which may have delayed the establishment of complex life, were controlled by the biological availability of nitrogen.

    In contrast to modern oceans, data from ancient rocks indicates that the deep oceans of the early Earth contained little oxygen, and flipped between an iron-rich state and a toxic hydrogen-sulphide-rich state. The latter toxic sulphidic state is caused by bacteria that survive in low oxygen and low nitrate conditions. The study shows how bacteria using nitrate in their metabolism would have displaced the less energetically efficient bacteria that produce sulphide – meaning that the presence of nitrate in the oceans prevented build-up of the toxic sulphidic state.”

    The nitrate metabolism would, AFAIU, belong to cyanobacteria. Meaning they were the originators of the oxygen events two times, first oxygenating the atmosphere and surface ocean by oxygenating photosynthesis, then oxygenating the deep ocean by nitrogen fixation.

    Speaking of cyanobacteria, the short review of life may well be the biological consensus. But the early fossil record is still changing. The earliest fossils attributed to cyanobacteria morphotypes are just over 2 Ba old. [“Evolution of multicellularity coincided with increased diversification of cyanobacteria and the Great Oxidation Event”, Schirrmeister et al, PNAS 2013.] The first large phylogenetics work on cyanobacteria dates them to ~ 3.0 + 0.6/- 0.5 Ga bp. [Ibid; fig 1.]

    So what about the earliest fossils? IIRC Brazier et al overturned (if that was the consensus) most or all of the earlier fossils (Shopf’s et cetera), and reinstated traces back to ~ 3.4 Ga bp.

    Arguably I think some of the ~ 3.5 Ga bp stromatolites are still feasible due to displaying microstructures consistent with bacterial growth. And last but arguably not least, a recent paper has even resurrected the Isua BIFs @ ~ 3.8 Ga bp:

    “Iron isotope analyses of BIFs from the 3.7 to 3.8 Ga Isua Supracrustal Belt (ISB), obtained by micro-sampling of magnetite-rich layers and conventional analysis, as well as by in situ femtosecond laser ablation (fs-LA-ICP-MS), indicate a consistently narrow range of non-zero δ56Fe values.”

    “Although these BIFs have been metamorphosed to amphibolite-facies, the metamorphism can neither explain the range in Fe isotope compositions across bands, nor that between hand samples. The isotopic compositions therefore reflect “primary”, low-temperature sedimentary values. The positive δ56Fe values measured from the ISB magnetites are best explained by deposition of Fe(III)-oxides produced by partial oxidation of Fe(II)-rich ocean water. A dispersion/reaction model, which accounts for rates of hydrothermal Fe(II)aq input, rates of oxidation, and rates of Fe(OH)3 settling suggests exceptionally low O2 contents, <0.001% of modern O2 contents in the photic zone. Such low levels suggest an anoxygenic pathway is more likely, and the data can be well modeled by anoxygenic photosynthetic Fe(II) oxidation." ["Biological Fe oxidation controlled deposition of banded iron formation in the ca. 3770 Ma Isua Supracrustal Belt (West Greenland)", Czaja et al, Earth and Planetary Science Letters 2013.]

    So they predict that the Isua BIFs, and likely other early such around the 3.5 Ga bp time frame, are not indicative of cyanobacteria but other early photosynthesizers. (Similar to phototroph Fe utilizing societies found ~ 100 m down in some lakes even today.)

  12. the first “true” cell with a nucleus probably arose about 2 bya; and the first multicellular organism between 1 and 2 bya.

    I have been meaning to ask people what they think of Nick Matzke’s (of NCSE infamity) exam, I think, work from 3 days ago?

    “Even with more sophisticated relaxed-clock analyses, nodes that are distant from fossil calibrations will have a very high uncertainty in dating.

    However, endosymbiosis events and gene duplications provide some additional information that has never been exploited in dating; namely, that certain nodes on a gene tree must represent the same events, and thus must have the same or very similar dates, even if the exact date is uncertain. We devised techniques to exploit this information: cross-calibration, in which node date calibrations are reused across a phylogeny, and cross-bracing, in which node date calibrations are formally linked in a hierarchical Bayesian model.

    We apply these methods to proteins with ancient duplications that have remained associated and originated from plastid and mitochondrial endosymbionts: the α and β subunits of ATP synthase and its relatives, and the elongation factor thermo unstable. The methods yield reductions in dating uncertainty of 14–26% while only using date calibrations derived from phylogenetically unambiguous Phanerozoic fossils of multicellular plants and animals.

    Our results suggest that primary plastid endosymbiosis occurred ~900 Mya and mitochondrial endosymbiosis occurred ~1,200 Mya.”

    [“Primary endosymbiosis events date to the later Proterozoic with cross-calibrated phylogenetic dating of duplicated ATPase proteins”, Shih & Matzke, PNAS June 17; http://www.pnas.org/content/early/2013/06/12/1305813110.abstract ]

    So perhaps the first modern eukaryotes appear ~ 1.2 Ga bp, which is half the time since the GOE of ~ 2.5 Ga bp, and more time than it took life to appear in the first place. Is this realistic, why did it take so long?*

    * Personally I don’t think an earlier nucleated eukaryote root would be a problem. Megaviruses hints that amitochondrial eukaryotes may have evolved into near unrecognizable simplified parasites as a result of competition with much more energetic species.

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