Convergent evolution Evolution Intelligent Design

Convergent eye evolution shows that evolution is “easy”?

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Here’s an inventive turn of phrase from Nature:

“Eye evolution came easy for simple sea creatures
Family tree shows that jellies and their relatives evolved eyes independently at least eight times.”

Jellyfish and their kin have no brains and make do with rudimentary nervous systems. But an analysis now shows that these simple sea creatures evolved eyes multiple times, transforming basic precursor cells into a wide range of useful visual systems. Curr. Biol. (2018), “Eye evolution came easy for simple sea creatures” at Nature

Nothing like a bold approach to the problems of irreducible complexity! Imply, without stressing the point, that if the creatures were “simple,” the process must have been “easy” and therefore wthin the range of random Darwinian evolution.

Note: Box jellyfish have eyes with retinas, corneas and lenses. Others have different arrangements, some “simpler” (for now). – Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology, 7th edition. Cengage Learning. pp. 153–154. ISBN 978-81-315-0104-7

See also: At Science: Maybe the transition from single cells to multicellular life wasn’t that hard? So at the basic level, there is a program that adapts single cells to multicellularity? Yes, that certainly makes multicellularity easier and even swifter but it also make traditional Darwinian explanations sound ever more stretched.

How do cells interpret the “dizzying” communications pathways in multicellular life forms? Presumably, it was easy for all this signalling to just somehow fall into place once, a long time ago … One approach with an excellent track record is: Make expressions of doubt dangerous. That stops the problem from becoming visibly worse even while it mounts.

and

Evolution appears to converge on goals—but in Darwinian terms, is that possible?

17 Replies to “Convergent eye evolution shows that evolution is “easy”?

  1. 1
    Silver Asiatic says:

    Nothing like a bold approach to the problems of irreducible complexity! Imply, without stressing the point, that if the creatures were “simple,” the process must have been “easy” and therefore wthin the range of random Darwinian evolution.

    Yes – truly incredible how they did that.

    The evolution of one eye, perhaps someone could naively say it makes sense because it was in a complex organism that came very late with so much time for selection and with so much complexity in the organism, and all eyes came from this one.

    Now however, they flip the story upside down and it still works.

    Not just once, but eyes independently evolved 8 times and in the earliest most ‘simple’ organisms.

    Well, evolution did it so obviously it’s a lot easier to evolve an eye than we thought!

    That concept really works well for evolution. We see the abrupt emergence of non-ancestral body-plans in the Cambrian explosion. There’s not enough time for evolution or not enough innovation that mutations could create to cause it.

    The evolutionary ‘response’ is the same. “It must have been a lot easier to create body plans back then”.

    Obviously.

  2. 2
    Mung says:

    Hands, on the other hand, were obviously quite difficult to evolve.

  3. 3
    bill cole says:

    “Eye evolution came easy for simple sea creatures
    Family tree shows that jellies and their relatives evolved eyes independently at least eight times.”

    How can anyone believe this?

  4. 4
    PaoloV says:

    bill cole:

    “How can anyone believe this?”

    Why not?

    It’s published in prestigious Nature, hence it must be true. Right?

  5. 5
    Silver Asiatic says:

    It’s published in prestigious Nature, hence it must be true. Right?

    Even more than that – I will propose that virtually all evolutionists believe it. So, perhaps 99% of all evolutionary biologists believe that. Therefore it must be true?

    Answering Bill Cole’s question – I don’t know. I am just silenced in the face of it. It is beyond idiotic. It’s like something a 4-year old would say. Virtually the same structure and function of eyes just magically evolved independently 8 times in the jellyfish family alone.

    And yet, we’re not supposed to have any doubts about evolutionary theory.

  6. 6
    PaoloV says:

    Silver Asiatic:

    “we’re not supposed to have any doubts about evolutionary theory.”

    That’s correct. But more than that, doubters must be re-educated by exposing them to the massive literature supporting the theory.

  7. 7
    Pearlman says:

    ‘Convergent evolution’ is testimony of One common/designer creator The One designer/creator of all the base kinds.

    reference the ID and YeC RCCF framework for understanding science.

  8. 8
    Otangelo Grasso says:

    If it cannot be explained how Rhodopsins evolved, it cannot be explained how eyes evolved.

    Origin of phototransduction, the visual cycle, photoreceptors and retina

    http://reasonandscience.catsbo.....and-retina

    ” The eye evolved “. Really ??!!

    This following study and investigation are the most devastating providing an ultimate smackdown to the claim that the origin of eyes, even the most ” primitive ” ones, could be explained by Darwinian evolution. Once you have read it, you will be able to settle this issue once for all, and put it to rest. Eyes MUST be intelligently created.

    Origin of eyespots – supposedly one of the simplest eyes

    http://reasonandscience.catsbo.....dence#5768

    Nilsson’s famous paper on eye evolution published in 1994 serves still today as reference science article in regards to how the eye evolved and is often cited by proponents of evolution. It starts with an eyespot, and in a nice row of pictures shows how eyespots could have evolved to complex camera eyes. In the initial stage, the structure is a flat patch of light-sensitive cells sandwiched between a transparent protective layer and a layer of dark pigment

    In the last sentence of the paper, Nilsson writes : ” the eye was never a real threat to Darwin’s theory of evolution.”

    In the article Light and the evolution of vision in Nature magazine, the author writes:
    Chlamydomonas is green algae in the plant kingdom. Phototaxis is essential for it; moving towards light upon which they depend for energy and nutrition, yet also undergoing negative phototaxis to protect themselves against too intense a source of illumination. The eyespot is not the photoreceptor itself but rather a mass of carotenoid pigment shading the photoreceptor from light from one direction. This demonstrates the essential components of any visual system; any photosensitive organism needs a photoreceptor that detects the light. But that alone would not allow the organism to determine the direction of the light source. A pigmented spot reduces the illumination from one direction or changes the wavelength of the incident light falling on the photoreceptor, thus allowing the organism to move in the direction of the light or away from it. So third, a mechanism to promote movement is essential. To detect the light is one thing but to move towards or away from it requires a motor system; the flagella in Chlamydomonas. But also a mechanism is required by which detection of light can be translated into a change in flagellar movement, generally an ion flux of one kind or another.

    This demonstrates the essential components of this visual system:

    1. any photosensitive organism needs a photoreceptor that detects the light.
    2 A pigmented spot reduces the illumination from one direction or changes the wavelength of the incident light falling on the photoreceptor, thus allowing the organism to move in the direction of the light or away for it.
    3 a mechanism to promote movement is essential. it requires a motor system; the flagellae
    4- But also a mechanism is required by which detection of light can be translated into a change in flagellar movement, generally an ion flux of one kind or another. Trans-membrane calcium flux initiates a cascade of electrical responses causing depolarization of the cell and ultimately controls the flagellar beating pattern.

    This is an interdependent system composed of 4 essential components, photoreceptors, a pigment spot, the flagella, and ion flux, of which, if one is missing, the organism cannot move by phototaxis. Natural selection would not select any intermediate evolutionary step, since the system, with any of the four elements missing, would confer no function, and no advantage of survival.

    Question: Why did the authors begin their narrative with a ” flat patch of light-sensitive cells “? rather than with an explanation of how such a “patch” could have evolved? and what it would be good for, unless being there for a specific function, like vision, detection of light/shading, circadian rhythm etc., which always requires other parts that constitute a system of at least two parts?

    The claim is that a unicellular, “simple” organism, like Volvox green algae, may have been equipped with a photoreceptor organelle, and the eyes may have evolved from such an ancestral state. The story of proponents of the evolution of the eye goes as follows: The simple light-sensitive spot on the skin of some ancestral creature gave it some tiny survival advantage, perhaps allowing it to evade a predator. 1

    There is nothing ” simple “: eyespots like in Chlamydomonas reinhardtii algae, have 742 different proteins 8 ; they have an elaborate structure, and a high ultrastructural complexity 18 .
    Zoologist Dan-Erik Nilsson avoided asking the relevant question: What good is an eyespot for by itself?

    From the “simplest”, most rudimentary eye forms, like eyespots, to complex vertebrate eyes, like our camera eyes, rhodopsins are the first players in a complex chain of biochemical events. In unicellular organisms, like Chlamydomonas, eyespots shade dark from the light and interconnected with the flagellum, they either distance from clarity, or move closer to sunlight, depending on their needs. This is an interdependent system, where one has no function unless linked to the other.

    Rhodopsin is the central player in vision. There is no vision without it. Unless rhodopsin transforms light into a signal, and that signal is used by a signal transduction pathway to promote phototaxis, neither rhodopsins nor eyespots would bear function by their own. A flagellum cannot rotate to move the cell in the right direction unless it gets the right instructions.

  9. 9
    Otangelo Grasso says:

    Origin of correct protein folding, a major problem in evolutionary biology

    The precision upon which opsins must fold into their seven transmembrane configuration is staggering:

    Biophysicists at JILA have measured protein folding in more detail than ever before, revealing behavior that is surprisingly more complex than previously known. . . .2 the JILA team identified 14 intermediate states—seven times as many as previously observed—in just one part of bacteriorhodopsin, a protein in microbes that converts light to chemical energy and is widely studied in research. “The increased complexity was stunning,” said project leader Tom Perkins, a National Institute of Standards and Technology (NIST) “Better instruments revealed all sorts of hidden dynamics that were obscured over the last 17 years when using conventional technology.” “If you miss most of the intermediate states, then you don’t really understand the system,” he said. Knowledge of protein folding is important because proteins must assume the correct 3-D structure to function properly. Misfolding may inactivate a protein or make it toxic. Several neurodegenerative and other diseases are attributed to incorrect folding of certain proteins.
    https://www.nist.gov/news-events/news/2017/03/jila-team-discovers-many-new-twists-protein-folding

    An article in Nature magazine confirms :
    even as far back as the prokaryotes the complex seven transmembrane domain arrangement of opsin molecules seems to prevail without simpler photoreceptors existing concurrently. Darwin’s original puzzle over ocular evolution seems still to be with us but now at a molecular level. 4
    https://www.nature.com/articles/eye2015220

    Retinal chromophores:
    channelrhodopsin-1 and channelrhodopsin-2 (ChR-1 and ChR-2), are directly light-gated cation channels that contain a planar all-trans, 6-S-trans retinal chromophore, which undergoes 13-trans to cis isomerization upon illumination.

    Retinal is a unique molecule with a chemical design that allows optimal interaction with the opsin apoprotein in its binding pocket, and this is essential for the formation of the light-activated conformation of the receptor. 2 When a photon strikes this retinal chromophore and the light energy is absorbed by retinal, this light energy is used to cause one of the alkenes in retinal to undergo a configuration change. This configuration change causes a change in the conformation (the three-dimensional shape) of the opsin protein , which triggers the complex transduction cascade. All structural details in the retinal chromophore are functionally important.

    A paper reports an intriguing evolutionary conservation of the key components involved in chromophore production and recycling. The synthesis of retinal precedes a complex pathway of several enzymatic steps starting from carotenoids molecules. There would have been no evolutionary advantage to evolve such a pathway and its proteins, unless there was the know how to make the molecule with the correct structure, in order to work fine and fit correctly in the opsin pocket to form a functional Rhodopsin protein.

    Retinal, the chromophore that is covalently linked to the rhodopsin-type photoreceptors of the eyespot apparatus likely results from symmetric cleavage of ?-carotene by a ? -carotene-15,15 -oxygenase (BCO). candidate genes related to the animal enzyme have been identified in Chlamydomonas

    We have by this only scratched the surface. We would have to explain the precise interplay and complex mechanism between the eyespot and the flagella, describe the flagellum in all its complexity. But what has been demonstrated so far is, that eyespots are FAR FROM simple, and depend on many interdependent parts, which, if not fully interconnected and regulated, would not permit Volvox to swim either towards the light (positive phototaxis) or away from the light.

    We can safely say: Vision and its origin is best explained by intelligent design

    The eyespot plays an accessory role in photobehavioral responses and eyeless mutant would be able to perceive and respond to light. Recent study using the reactive oxygen species (ROS), leads to the identification of novel eyeless mutant of Chlamydomonas exhibiting strong phototaxis responses. These reports support the earlier made hypothesis, that the photoperception in Chlamydomonas is not confined to eyespot. One possibility is that the bacterial rhodopsins localized in the flagella of Chlamydomonas might be responsible for a non-directional phototransduction of this organism. The eyespot-guided phototaxis is very important for the zooplankton larvae of marine invertebrates and is proposed to mediate larval swimming towards the light. Recently, it has been proposed that eyespot localized opsin of the Platynereis are the photoreceptors for controlling phototaxis of this organism. It would be interesting to elucidate the role of intraflagellar transport (IFT) machinery in the trafficking of opsin in the eyespot of the Platynereis, which would shed light on evolutionary link of the of the IFT mediated trafficking of the rhodopsin(s) in nature. The involvement of IFT in the eyespot localization of rhodopsin would further support its role in intracellular trafficking of proteins similar to the case of immune synapse assembly in higher animals.

  10. 10
    bill cole says:

    Paolo V

    That’s correct. But more than that, doubters must be re-educated by exposing them to the massive literature supporting the theory.

    You’re committing an ad populum fallacy.

    The massive literature all makes one big assumption that universal common descent is true. Yet there is no testable mechanism that supports this. Wake up and smell the coffee.

  11. 11
    PeterA says:

    Otangelo Grasso:

    Excellent comments 8 & 9!
    Thanks!!!

  12. 12
    PeterA says:

    Pearlman,

    What’s YeC RCCF?

    Thanks

  13. 13
    OLV says:

    bill cole (10):

    Knowing Paolo Verspi well, I think he should be nominated for an Oscar for his excellent performance of the main character of the tragic comedy “the Darwinist”.

    I’m sure his cheek hurt from the tongue pressure when he wrote all that nonsense.

  14. 14
    Axel says:

    … or else severly sanctioned, career-wise, Paolo.

    Siler Fox, arent you being a little harsh ? A four-year old ? Not a five or six-year old ? No… on mature reflection, I suspect you have it about right, give or take a month or two.

    It ought to be hilarious, but today the ubiquity of potential hilarity in the context of the past, no longer applies, does it ? Not just in science, although that is a beacon of madness, but generally with the demise of Christendom, mostly from within.

  15. 15
    Axel says:

    @ your #8 and #9, Otangelo

    No need to get all technical on them. That’s not what science is about, apparently….. If the logic doesn’ fit, bin it, and follow your dream. Don’t let stick-in-the-muds put you off with all that pedantic, empirical nonsense. Be all you can be ! ‘n’ stuff.

  16. 16
    Silver Asiatic says:

    Axel – yes, true. When the children were pointing to the emperor parading naked through town with his invisible new garments, the kids were laughing hysterically.

    They just saw a buffoon who thought he looked grand, but who actually lost all of his dignity and they knew how funny that was.

    But they also didn’t know that the same emperor imposes unjust taxes, incites wars, imprisons his enemies and oppresses people – all with the same arrogance he has in his new royal clothes.

    So, we laugh at the Darwinists for a moment. They’re just ignorant buffoons, telling lies, acting like they are important. But we also stop laughing very quickly because we can see how much power they have and the damage they do to the entire world.

  17. 17
    Axel says:

    Spot on, Silver Fox. The jaded, rueful laughter only tells a small part of the story ; only hints at its ugliness.

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