June 29, 2011 | David F. Coppedge

Complex Arthropod Eyes Found in Early Cambrian

Complex eyes with modern optics from an unknown arthropod, more complex than trilobite eyes, have been discovered in early Cambrian strata from southern Australia.  The exquisitely-preserved imprints of the eyes in shale were reported by Lee et al. in Nature.1  The abstract started by quoting Darwin and affirming evolution, but then revealed evidence that complex eyes go further back in the fossil record than previously thought possible:

Despite the status of the eye as an “organ of extreme perfection”, theory suggests that complex eyes can evolve very rapidly. The fossil record has, until now, been inadequate in providing insight into the early evolution of eyes during the initial radiation of many animal groups known as the Cambrian explosion. This is surprising because Cambrian Burgess-Shale-type deposits are replete with exquisitely preserved animals, especially arthropods, that possess eyes. However, with the exception of biomineralized trilobite eyes, virtually nothing is known about the details of their optical design. Here we report exceptionally preserved fossil eyes from the Early Cambrian (~515 million years ago) Emu Bay Shale of South Australia, revealing that some of the earliest arthropods possessed highly advanced compound eyes, each with over 3,000 large ommatidial lenses and a specialized ‘bright zone’. These are the oldest non-biomineralized eyes known in such detail, with preservation quality exceeding that found in the Burgess Shale and Chengjiang deposits. Non-biomineralized eyes of similar complexity are otherwise unknown until about 85 million years later. The arrangement and size of the lenses indicate that these eyes belonged to an active predator that was capable of seeing in low light. The eyes are more complex than those known from contemporaneous trilobites and are as advanced as those of many living forms. They provide further evidence that the Cambrian explosion involved rapid innovation in fine-scale anatomy as well as gross morphology, and are consistent with the concept that the development of advanced vision helped to drive this great evolutionary event.

How the immediate appearance of a complex trait like vision could “drive” an evolutionary event seems strange, since the eyes were already there during the event.  No transitional eyes simpler than this were reported.  Though the authors gave lip service to evolution, all the evidence pointed to more complexity and adaptive perfection than was thought possible for animals this early.  Here are some details about these compound eyes:

  • A side-by-side comparison of the fossil imprint with a living insect eye shows virtually no difference in complexity.
  • The fossil eye was compared by the authors in complexity to a dragonfly eye: “The ratio of lens diameters in the bright zone to lens diameters in the margin (~2.5:1) exceeds that found in other Cambrian arthropods (trilobites and cambropachycopids) and is comparable to that in many modern taxa such as dragonflies,” they said.
  • “The extremely regular arrangement of lenses seen here exceeds even that in certain modern taxa, such as the horseshoe crab,” the authors said.
  • The eyes apparently gave their owners binocular vision: “This bilaterally symmetrical arrangement generates binocular vision,” they suggested, though proof will require discovery of articulated remains.
  • The eyes would have been good for a fast predator: “Acute forward vision and lower-resolution peripheral vision are typical of predators that require excellent frontal vision for estimating distance and detecting prey against complex backgrounds; they are also typical of fast-moving organisms in which acute peripheral vision is precluded by a high retinal angular velocity.”  That being the case, the animals would have had many other advanced features in addition to eyes.  “The complexity and large size of the Emu Bay Shale eyes strongly indicate that they belong to an active arthropod, probably a large predator.”  These eyes, however, were smaller than those of Anomalocaris.
  • This is a game-changer: “The arrangement and size gradient of lenses creates a distinct ‘bright zone’ (also called the acute zone or fovea), where the visual field is sampled with higher light sensitivity (due to large ommatidia) and possibly a higher acuity (due to what seems to be a more parallel orientation of ommatidia),” they said.  “Such visual specializations, characteristic of many modern taxa, are otherwise unknown in the Early Cambrian.

The animal type is not known, since articulated remains have not yet been found.  The imprints may be from shed corneas, they said. Their graphs show that these eyes exceed most other arthropod eyes of the Cambrian in complexity, even among those of the Ordovician. 

In their concluding paragraph, they affirmed use of the phrase “Cambrian explosion” as a real event.  They could offer no explanation for the evolution of these eyes, nor did they put forward any transitional forms.  They merely assumed evolution occurred quickly somehow:

The evolution of powerful vision is one of the most important correlates of the Cambrian explosion and has been proposed as a trigger for this event. However, although the overall shapes of eyes are known for many Cambrian organisms, intricate details of the visual surface are known only for trilobites and the tiny stem-crustacean cambropachycopids, which have bizarre, proportionately huge and medially fused compound eyes. In addition, indistinct ommatidia are preserved in a few Chengjiang fossils, including the non-biomineralized arthropods Isoxys and Cindarella. Isoxys inhabited both dim and bright pelagic environments whereas Cindarella probably inhabited a bright benthos. The specimens described here represent the first microanatomical evidence confirming the view that highly developed vision in the Early Cambrian was not restricted to trilobites. Furthermore, in possessing more and larger lenses, plus a distinct bright zone, they are substantially more complex than contemporaneous trilobite eyes, which are often assumed to be among the most powerful visual organs of their time. The new fossils reveal that some of the earliest arthropods had already acquired visual systems similar to those of living forms, underscoring the speed and magnitude of the evolutionary innovation that occurred during the Cambrian explosion.

Live Science posted a summary of this finding, showing how the visual acuity of the animal bearing these eyes was superior to that of trilobites and indistinguishable from the acuity of the dragonfly.  Though the dragonfly has eight times the number of individual ommatidia, the Cambrian eyes surpassed those of other fossil arthropods dated 40 million years later.  Live Science’s article also quoted the authors’ confirmation of the Cambrian explosion: “The new fossils reveal that some of the earliest arthropods had already acquired visual systems similar to those of living forms, underscoring the speed and magnitude of the evolutionary innovation that occured during the Cambrian Explosion.” 

PhysOrg featured a video showing the fossil in 3-D and comparing it to other arthropod eyes.  The article tried valiantly to save evolution from this new evidence:

Their discovery reveals that some of the earliest animals possessed very powerful vision; similar eyes are found in many living insects, such as robber flies. Sharp vision must therefore have evolved very rapidly, soon after the first predators appeared during the 'Cambrian Explosion' of life that began around 540 million years ago.

Given the tremendous adaptive advantage conferred by sharp vision for avoiding predators and locating food and shelter, there must have been tremendous evolutionary pressure to elaborate and refine visual organs.

Science Daily said the fossils look like “squashed eyes of a recently swatted fly.”  How could evolution explain this?  The headline put forth its thesis:  “New Fossils Demonstrate That Powerful Eyes Evolved in a Twinkling.”  Stuff happens, and it happens quickly.

1. Lee, Jago et al., “Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia,” Nature  474  (30 June 2011), pp. 583–584, doi:10.1038/474583a.

OK, skeptics, face the facts.  Complex eyes, “organs of extreme perfection,” are already there in the early Cambrian.  Where are the transitions?  Trilobite eyes were already astonishing, and now these exceed them in complexity, and appear earlier than the best examples of complex trilobite eyes!  They are comparable to modern insect eyes.  You cannot call these a trigger of the Cambrian explosion–what nonsense!  That’s like saying, “Revolvers appeared out of nowhere, and triggered the Civil War.”  The eyes were already there, fully formed, fully operational, even within the incestuous dating scheme of the evolutionists.  Arthropods are exquisitely complex animals, crowned with glorious eyes as well as many other senses and systems that allow for rapid motility and function.  Who needs a Cambrian rabbit?

You can go to the Amazon reviews of the DVD Darwin's Dilemma and see Donald Prothero self-righteously rant against ignorant creationists, announcing with his professorial authority that the Cambrian explosion was no explosion but was a long slow fuse.  Hold this paper up to his face.  Here a team of Darwin-worshiping scientists with no love for intelligent design, publishing in the world’s leading science journal Nature (also no friend of intelligent design) called it an explosion five times in their paper.  They discovered organs of extreme perfection in the early Cambrian with no transitions, only offering in defense of Darwin the vain hope that eyes might evolve rapidly, tossing that hot potato to Nilsson and Pelger (whose computer model was amply debunked long ago–see ENV 2006, ENV 2007, ENV 2011).  Science is supposed to be factive, not fictive.

The Cambrian explosion is affirmed; complexity appears suddenly without transitions; Darwinism is falsified; the inference to the best explanation is intelligent design.  Let the world know.

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  • mrsmith203 says:

    Great story.  How can the “science media” write this stuff with a straight face?  This is NOT how it was supposed to be…….

  • josh says:

    If they find a rabbit in the Cambrian, it will be called the “trigger”.

  • the night watchman says:

    Does the quoted phrase “organs of extreme perfection” appear in the original article?  Does a phrase similar to “organs of extreme perfection” appear anywhere in the literature of evolutionary biology?  Is such a phrase even grammatically adequate?  I’m sure the answer to all three questions is “no.”

  • Editor says:

    “Organ of extreme perfection” is in the first sentence of the paper, for which the authors’ reference #1 points to Darwin in Origin of Species (see ch 6, subheading “Organs of extreme Perfection and Complication”).  Complain to Charlie.

    Note to readers: Ad hominems are stripped out of comments.  Stick to the issue like GuyM did. 

    GuyM, thank you for your comment, but try to supply evidence that evolution produced these eyes that might convince a Darwin skeptic.  By evidence I mean without (1) circular reasoning (“eyes were known to have evolved”), (2) beliefs (“believed to have driven”), or imaginary scenarios (“helps with that idea”).

  • GuyM says:

    Thanks David,
    Firstly “(1) circular reasoning (“eyes were known to have evolved”)” this comes from my statement “Eyes were known to have evolved well before the Cambrian explosion”. OK, I can see how you see this as circular.. I’m assuming evolution to “prove” or support evolution. I’m just as happy to take the word “evolved” out of that sentence and make it “Eyes were known to have existed well before the Cambrian”. It still carries the overall meaning. Given that eyes existed before the Cambrian you would expect to see some complex eyes in the beginning of it as evolution would predict that sight (eyes) would continue to improve because it is an important selective trait. I suspect that it would be more problematic, for evolution, if there weren’t.

    (2) beliefs (“believed to have driven”) 
    I believe smile it is the word “believed” you are objecting to here in that you think it implies “belief without proof (or evidence)”. Part of any scientific theory is that it should be able to explain current data and be predictive, if it can’t do that then it is useless as a scientific theory. When looking at the Cambrian from the perspective of the theory of evolution you need to have mechanisms within evolution that explain it. That mechanism is natural selection, Darwin’s great observation. Natural selection would predict that the development of sight would be a large selective force, I don’t think many would argue that it would be of huge benefit to be able to see your predator clearly. That being the case, when sight develops (evolves, using an evolutionary perspective) you would expect an expansion and a “rapid” increase in the complexity of eyes. (I “believe” that the Cambrian was also the start of hard skeletal structures which would also be a selective bonanza.) So the word “believe” in my statement is a word that is really meant to represent the above in that, sight is the one of the factors that is “predicted” to have been a driving force behind the Cambrian. (Maybe even the word “predicted” is not quite right?) Basically, in order to have rapid expansion you would expect to see the evolution of strong selective features, if you did not then the theory of evolution would struggle.

    “helps with that idea”, OK, that’s a pretty weak statement, I don’t claim to be either an evolutionary biologist or a good writer smile. Maybe I should have said something along the lines of “The discovery of more complex eyes in the early Cambrian, than were previously known, actually helps explain the rapid development of complexity of life”. This really ties in with number 2.

    In answer to “but try to supply evidence that evolution produced these eyes that might convince a Darwin skeptic” 
    I find this question a bit skewed, you can’t find evidence that evolution “produced” these eyes, this sounds, to me, like you expect to find some sort of machinery that manufactures eyes. It is more correct to say that the eyes fit in with what evolution predicts and hence supports evolution. If you assume that evolution is true you would expect to find a range of rudimentary eyes that evolve into more complex ones and this is what we find in the fossil record. This particular eye, that is the topic of this post, is not the first known eye. There were known pre-Cambrian eyes so you would expect to find much more complicated eyes evolving within the Cambrian period and you would expect them to develop rapidly as sight is a strong selective advantage. So what we have is an eye that fits in with evolutionary theory and hence supports it. That is the “evidence that evolution produced these eyes”. If a complex eye was discovered with no possibility of more primitive eyes before it, then there may be a case against the theory of evolution however this is not the case.

    From a personal level I don’t see any other theory that satisfactorily explains the fossil record and the diversity of life on this planet like the theory of evolution.

    I hope that is at least understandable smile and not a garbled mess.

  • Editor says:

    Guy:  For an evolutionist, your civility is refreshing.  But I don’t think you yet realize the extent of your argument’s circularity and question-begging. For this, I refer you to the Darwin’s God blog that explains it in more detail:
    (I suggest you take up your discussion there, since this is a news site, and we must move on.) 
      I did want to correct one error about natural selection (NS)—it is not a force or a pressure, and it cannot drive anything (see Henry Gee, evolutionist former editor of Nature, explain this here: http://creationsafaris.com/crev1202.htm#darwin197).  NS is not a force any more than a hub in a pinball game is a force.  And this pinball game has no operator and no scoreboard (Note: survival is not a winning score—evolution cares not if things survive or go extinct.  Caring is a Christian virtue). 
      Given these requirements (no assuming evolutionary progress, no caring, no explaining, no expecting anything, no benefits, no evolutionary advantages—all circular), evolutionary theory is indistinguishable from the Stuff Happens Law (SHL, see http://creationsafaris.com/crev200809.htm#20080915a ).  Why?  Because both mutation and NS are random. Mutations are clearly random, and NS is random, because there is no goal or direction, and the environment that “selects” (a hopelessly personified concept) is random.  When you add random to random, you get random.  Stuff Happens.
      So, to present a consistent evolutionary explanation that might convince a Darwin skeptic, what you need to do is purge your mind completely of any goal, purpose, or values (including survival).  You need to be a cold-hearted, uncaring, neutral observer. Look at these animals as possessing no desires, goals, or aims,  Then watch randomness take over. Describe the sequence of random stuff that happened (make sure it’s undirected, like Brownian motion, not progressive, as Henry Gee warns). 
      If you want to argue that Stuff Happens, and eyes appeared, I would say you have a vivid imagination supporting a prior assumption, but not a scientific theory.  Best of luck.

  • jake says:

    David, you say that natural section is a random, non-driving force, but I don’t see how that is. Consider the classic example of a gazelle and the cheetah. Through random chance one gazelle in a herd has slightly better genes for escaping a cheetah attack; consider speed, agility, reaction time, and one gazelle has slightly worse genes so that in an attack, the gazelle with the worse genes gets eaten and doesn’t pass on its genes, and the better genes do get passed on. you cannot possibly say that each gazelle had a 50% chance of getting eaten, can you? natural selection selects for the fittest among a group of individuals within a population of individuals. How about sexual selection? Rams with the most effective ramming genes (horn and skull size/strength, speed, etc) will pass on their genes more frequently than those with the worst genes. Sure the process of gene mutation and such is random, but how can you say that Evolution is clearly random? What makes it so exciting is that it ISN’T entirely random.

  • huttarl says:

    Good reporting … I saw this article too, and posted about the disconfirmation of evolutionary predictions by fully modern complex eyes appearing early in the Cambrian. Also agreed with you on the saving-evolution spin of “wow, they must have evolved very rapidly.” So I was encouraged to see your elaboration of those points, and the fact that Prothero’s damage control statements about the Cambrian “slow fuse” are shown to be empty PR.

    I think you misunderstood one aspect of what the article was saying… I think the trigger (driver) they are referring to was not complex eyes themselves, but “tremendous evolutionary *pressure* to elaborate and refine visual organs.” Granted, they phrase it misleadingly in other places, but I assume this must be what they mean. Even this point is feeble… you’ve posted elsewhere about the inadequacy of a “need” to drive (oxymoron?) sightless, undirected evolution. But I don’t think they are saying an already-developed feature helped drive evolution.

  • huttarl says:

    @GuyM, “The Cambrian explosion was a period of rapid development of complexity and diversity, not the start of development. Eyes were known to have evolved well before the Cambrian explosion, these were just the most complex of the ones in the early Cambrian (that we currently know of).”

    Guy, the quoted article states “The new fossils reveal that some of the earliest arthropods had already acquired visual systems similar to those of living forms”, expressing surprise at how early modern visual systems appeared. PhysOrg puts it, “Their discovery reveals that some of the earliest animals possessed very powerful vision; similar eyes are found in many living insects, such as robber flies. Sharp vision must therefore have evolved very rapidly, soon after the first predators appeared.”

    The evolutionary story is supposed to be characterized by gradual change, building from simple to complex. Here we see complexity very early on, necessitating an abandonment of gradualism, contrary to evolutionary expectations. You can only turn this into support for evolution by bending over backwards.

  • GuyM says:

    The Cambrian explosion was a period of rapid development of complexity and diversity, not the start of development. Eyes were known to have evolved well before the Cambrian explosion, these were just the most complex of the ones in the early Cambrian (that we currently know of). This is NOT proof against evolution, it supports evolution. One of the developments that is believed to have driven the expansion in the Cambrian is sight. finding a complex eye in the early Cambrian helps with that idea, it does not hinder it.

  • kiri says:

    The demise of the Theory of Evolution has been predicted every year for the past 100 years! It’s just like predictions of the end of the world—-they never come true.

  • John S says:

    Guy, you are awesome!  I don’t agree with you but as was stated your civility is refreshing, unknown in the history of this discussion.  At least in my limited experience.  You actually listen to the other side, and take time to specifically answer and do it in a humble way.  I don’t know if you are a Christian or not, but you speak in a more Christian way than most Christians.  Thank you.

    As far as eyes go, it’s my understanding that evolution would dictate that a single eye would have evolved, then from one eye another or multiple others would develop or split (same with ears, arms, legs).  I’m not aware of any single-eyed organisms, they appear on the scene in pairs or multiples, which to my mind is unnacceptable Darwinially or philosophically.  Symmetry or redundancy are plans not random. If the eye evolved multiple times as Darwinists posit there should be many examples of creatures with one eye.  Just another detail for consideration.  And what good is an eye without a connected brain to process the info, how did that happen without a plan?

  • John S says:

    Jake, I don’t have a job, I’m going to an interview against one other candidate. I must provide for my progeny.  I will follow him home and murder him at midnight and cleverly cover it up.  I win the job, he dies.  I am the Man-ram with the most effective size, strength and intelligence genes. My line will reproduce and we will pass along our genes as natural selection dictates – at whatever the cost to any other organism.  (eg Nazis).  Evolution is so very exciting!  Can you tell me if there is anything wrong with the above scenario?

  • ironclad says:

    GuyM: “Eyes were known to have evolved well before the Cambrian explosion.”

    Guy, exactly how do you know this and where is the evidence?  If that were the case, the authors of the present article and the other scientists that have been dealing with this question (complexity of the visual apparatus) would not have been using language full of surprise and wonder.  There should have been some mention about those very early forms of ‘simple’ vision.

  • Rkyway says:

    Evolutionary pressure? What’s that? Is it like the pressure of methane gas? The pressure of gas after a bad meal? The pressure in a propane tank? Has anyone observed evolutionary pressure? Since we know it was a tremendous pressure I assume this means they were able to measure it.


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