• Color Blindness and How Easy Evolution Really Is

    I love learning new things. I was especially happy when Neil Shubin’s “Your Inner Fish” was made into a three part series on PBS. (View here for a short time.)

    I loved the book (even did a chapter-by-chapter review that was a lot more fun that Darwin’s Doubt).  But it was really nice to see things that weren’t in the book. New information. New evidence for evolution and our common ancestry with… well… everything.

    One new thing I learned was particular interesting given my interest in the creationist movements. One often hears about how difficult it is for complex things to evolve. Take vision for example. The eye is really complex and all the parts have to work together or there’s no vision. Well, that’s true… now. But it hasn’t been true throughout the history of life. The eye has evolved to be more complex as those animals with really good vision were simply better at surviving.

    But a scientist named Jay Neitz (featured in the third episode of Your Inner Fish) and several other scientists reported on just how easy it is to change the vision systems in the eye. The paper was in 2009 in Nature. [1] PDF

    First we need to talk about how color vision works. Humans have three types of cone cells in the eye. These are designated S, M, and L by the types of EM radiation that those cones respond to. Remember the phrase ROY G. BIV? That’s the visible light spectrum (a rainbow). Red is the longest wavelength, while violet is the shortest wavelength.  S-cones is our eye respond best to short waevlengths, the violet and blues, and very weakly to the other colors. The M-cones respond strongly to yellows and greens, but weakly to blues and reds. While the L-cones respond strongly to reds and oranges and weakly to blues. The combination of how these cones react give us a full spectrum of color vision.

    Well, most of us.

    Some people have a mutation in one of the genes (there are several) that controls the light sensitive pigments in our eyes, called opsins. The genes for these opsins are on the X chromosome.[2] This is why there are more males with color-blindness than females.  Females have two X chromosomes, so they have a ‘backup’ copy of the gene if one is damaged. This also explains the concept of tetrachromacy, which MAY mean that some women have four different cones instead of the usual three. Perhaps, they can actually differentiate more colors than us plain old trichromacy people.

    What I learned from Your Inner Fish was that the blue/green opsin in the L/M-cones seems to be a relatively recent innovation in evolution. They are really close together on the X_chromosome and they are really very similar. It’s almost as though the gene segemnt was duplicated, then one gene mutated and now responds to a different part of the spectrum than the other. That’s one hypothesis.

    Dr. Neitz was wondering if it’s really that simple. Could such a single change, a few mutations in a gene, really allow an animal to see more colors? Or would the brain simply not be prepared for it.

    In squirrel monkeys (Saimiri sciureus), some females have trichromatic vision, but all males are red-green color blind. The authors trained some male monkeys (I hate that term) to identify the part of a touch screen that had different colors.  If they got the selection correct, they got a treat.

    Squirrel monkey at the Phoenix Zoo http://en.wikipedia.org/wiki/File:Monkey_toes.jpg
    Squirrel monkey at the Phoenix Zoo

    These tests are exactly like the color-blindness tests that you get at the optometrist’s office.  Except the monkey’s got a reward for getting it right.

    After testing for more than a year, two males were injected with a virus that had been modified for a gene therapy role. The recombinant virus contain a human L-opsin gene with an L/M opsin enhancer and promoter. And yes, the three injections of viral particles was just underneath the retina. Shudder.

    If the opsins were all that were needed to see three colors, then the monkeys would be able to see colors that they hadn’t seen before. But if some rewiring of the brain was required, then the monkeys still wouldn’t see red/green even with the gene producing the L-opsin.

    A brief aside here. This is also a test of creationist claims. If things like color vision are as complex as creationists think, then just a simple change like this shouldn’t change anything in the monkeys. But if we do see a change in the monkeys ability to see colors, then the creationist claim is wrong. Simple changes to genes can produce very dramatic changes.

    Twenty weeks after the injections, the two males were no longer color blind. They could register all color differences. In fact, if I’m reading this paper correctly, it appears that the human L-opsin is superior to the squirrel monkey L-opsin because the males could actually see colors more effectively than the females.

    So, we see that the monkey brain can handle the additional inputs in an entirely different color spectrum. And it can readily use that additional information in a direct (profitable) way.

    And all that is required is a gene. This supports the claim that gene duplication followed by mutation is a method by which new abilities can be generated in populations of organisms.

    The other exciting thing is that this procedure may provide a way to restore full color vision to humans with certain types of color-blindness.


    [1] Mancuso, K. et al. Gene therapy for red-green colour blindness in adult primates. Nature 461, 784–7 (2009).

    [2] There is also an opsin gene on the human #7 chromosome. That’s the S-type.

    Category: CreationismEvolutionfeaturedResearchScience


    Article by: Smilodon's Retreat

    • kraut2

      I found this result astonishing.
      Apart from creating a new opsin, it also means that the brain was prewired or preprogrammed to interpret the signal correctly. This also is counter to creationist claims that all or most mutations are negative, as this precondition is just neutral – until the signal is actually received.

    • I too found that part of the program to be startlingly effective evidence against the “complexity” bafflegab of creationists.


      I’d be careful using the term “prewired” around creationists because they will assume that it means “designed.” As I understand it, all that’s happening is that the brain is receiving more nerve signals allowing a finer distinction among the wavelengths of light hitting the retina. We don’t know if monkeys perceive colors the way we do (heck, I don’t know if you perceive colors the way I do) but the important fact is that increasing the types of opsins merely increases the information the brain receives from the outside world. The brain didn’t have to be “prewired” since that’s what the wiring was doing in the first place.

    • RexTugwell

      Thank you, Smilodon.

      And all that is required is a gene.

      I haven’t laughed so much since Tuesday. Did you read chapter 11 in Darwin’s Doubt “Assume a Gene” like I suggested? Considering your track record so far, probably not. If you did, you wouldn’t have made such a silly, uninformed and naive assertion.

      Reminds me of Steve Martin’s classic: “You can be a millionaire and never pay taxes.”

      You say “Steve, how can I be a millionaire and never pay taxes?”

      First…get a million dollars.

      • SmilodonsRetreat

        And yet, you offer nothing to counter my claim, nor the claim in the peer-reviewed article.

        And since you refer me to someone who is a known liar, then I can only assume that you laugh because you actually don’t have a clue what’s going on.

        • RexTugwell

          I don’t have a clue, huh? Why do you assume that I would want to counter anything in the peer-reviewed article? I only dispute your claim that evolution is easy. And this isn’t even evolution. After all, will these monkeys have offspring that will have trichromatic vision? I’m pretty sure they won’t. So this evolutionary “path” stops with them. It’s not enough to show intelligently designed adaptations in the lab and then claim “evolutiondidit”.

          It’s almost as if Meyer had you in mind and your silly “and all that is required is a gene” mantra when he wrote “Assume a Gene”. Do you finish anything you start? Whether Meyer is a liar or not is irrelevant. (Of course, Meyer is not a liar) However, for someone who was going to shred every point that Meyer makes in DD, you have offered such a disjointed and incomplete response, that one is left wondering if you can refute anything of scientific substance in the book. By the way, Dr. Janis can join you in being among those who can’t seem to finish a “review” of DD.

          From the beginning, your problem was that you turned your review of the book into a rebuttal. At that point, you could go no further. I could read you like a book (pun intended). I knew you wouldn’t finish the book. I knew you wouldn’t address the substantive chapters and I definitely knew you’d abandon chapter 13.

          I want to thank you for participating in my little experiment. You performed admirably.

          • SmilodonsRetreat

            Meyer has been shown to be a liar. It’s that simple. He has lied about what Marshall said and what Gould said and what every paper I have commented on said.

            Why do you still think he’s a trustworthy source? Oh yeah, because he says the things you want to hear.

            As far as the experiment here, it was never intended to show that the trait could be passed down to offspring. Once again, you completely miss the point.

            • RexTugwell

              No adapted offspring, no evolution. Learn it, love it, live it.

            • SmilodonsRetreat

              You really don’t understand the point of this experiment do you?

              Let me explain, in detail.

              Creationists, like you think that gene duplication cannot result is evolution for some reason, which is never fully explained. This may be because things like eyes are so complex that one little change can’t improve them without a host of other improvements.

              If you don’t like my description of what you believe, then I would suggest you get with other creationists and work out exactly what you all should be saying. Until you expressly say what you think, then I only have other creationists’ claims to go with.

              The problem with that claim is that it is not true… as this experiment (and dozens of others) easily show.

              Let’s think about what happened here. A primate was injected with a HUMAN opsin gene. Specifically a gene that allows for human three color vision, whereas the primate only has two.

              First, the gene worked. That in and of itself confirms that common descent is valid. Creationists like to say that also confirms common design, but have to explain any difference between that an evolution.

              Second, the gene allowed the primates to see trichromatically. NO OTHER CHANGES WERE REQUIRED!!!!!

              There was no change to the brain, the eye, the nerves, or anything else. Yet, the primate could see trichromatically, instead of bichromactially. This SHOULD tell you that a gene duplication followed by minor mutations DOES create “new information”, however you choose to define it.

              Therefore, any claims to the contrary are wrong. You can now stop using that claim. If you continue to use that claim then A) you are exposing your complete ignorance of science and/or B) you are choosing to lie about the evidence.

            • C) Science makes them afraid that they aren’t the special pet of some “Big Daddy.” In some ways, I feel sorry for them … they are hiding under the furniture in case the universe doesn’t like them.

            • Tim Tian

              but then if we inject them near the testicles…

      • I haven’t laughed so much since Tuesday.

        And here I thought a loon had wandered down from Canada.

        The funny thing about IDers is for all their talk about “information,” how little of it they actually convey. So Opsin2 and Opsin3 are very similar. So why couldn’t a duplication and a very small, but very valuable, mutation occcur?

        Let the handwaving begin!

        • RexTugwell

          John, you obviously didn’t read chapter 11 either. Otherwise you’d be clued into my laughter. But alas, ignorance is bliss and no one here has the courage to read Meyer’s book. I don’t deny gene duplication happens. I don’t deny “a very small, but very valuable, mutation occcur[s][sic]”. No IDer I know denies it. It’s only your strawman version of ID that makes such a claim.

          And I don’t dispute anything in Mancuso, et al’s paper. I only dispute that “evolutiondidit”. Especially since intelligent agents made it happen in the first place. Sure genes can mutate – sometimes in very beneficial ways. But how do those genes arise in the first place. Smilodon says “mutations, Duh.” I say it can’t happen. Read chapter 11. Otherwise stop asking such uninformed questions.

          • Doc Bill

            Yeah, I agree with Rex. Some intelligency thingy started the whole ball of wax that Meyer so eloquently, and backed by much personal research, describes in Chapter 11. We get it, Rex.

            Now, why don’t you go back down to your basement and tug something. Well.

            That’s a good boy, thanks.

            • RexTugwell

              Stop making fun of my name!!

            • Doc Bill

              Number 1, I agreed with you, what more do you want, Mr. Grumpy Pants.

              Number 2, if you want people to stop tugging well at your name, get a new name.

              Number 3, hmmmm, Rex … Rex. Where have I heard that before. Dog’s name, nope. T-Rex, nope, although you’ve got the dinosaur part down pat, T-Rex is a lot more popular. Oh, yeah, Oedipus Rex. Tragic name.

          • SmilodonsRetreat

            Let me get this straight. You say that a process that is known to occur happened. But you don’t believe that it happened except by the direction of an unknown intelligent agent, using unknown abilities, over an unknown amount of time, in a way that is completely undetectable.

            And we’re the ones who don’t understand!??!?!?

            Tell me, was the ‘intelligent agent’ that did the Opsin work between humans and the ancestral primates the same agent who did the work in the Cambrian, some half a billion years earlier?

            And finally, you expect someone who is a known liar to explain something correctly and that is somehow correct when every scientist who actually does work with evolution, biology, and the like (including Axe and Drager) all show that evolution happens.


          • SmilodonsRetreat

            Rex, you were right, Chapter 11 is a revelation.

            I though Meyer couldn’t get any worse, but man was I wrong. Thank you, this is truly an inspiring chapter.

            Whatever Meyer is, you sure as heck can’t call him a researcher. This is simply stunning. My second part is in progress. I’ve had to e-mail a couple of scientists for confirmations and some other materials.

            I am so glad you kept hounding me to work on Chapter 11. This is awesome.

            • RexTugwell

              See what happens when you actually read a book you say you’re reviewing. You can really learn something new. Given my experience with you though, I’m counting on being disappointed. Who knows…

              I do hope your revelation has to do with the formation of novel genes.

              You’re still on the hook for Chap 13 don’t forget

            • SmilodonsRetreat

              You’re right. I swore Meyer couldn’t be more of a moron, but he is.

              It’s actually amusing. I’ve contacted one of the authors of something Meyer references, but it appears as it Meyer is refuting a paper that those authors didn’t even reference. Talk about a strawman.

              Of course, Meyer doesn’t actually provide citations to any of this, so I had to actually… you know… look it up myself.

              I’m actually shocked that you, being the skeptic you are, didn’t also look up Meyers uncited claims and see that he was going to attack a paper that the authors of the refutation never used. Of course, I guess that means that the paper the authors did use is still valid and Meyer is wrong about everything in this entire chapter.

              That’s Meyer’s implication by the way. Unless someone counters it, it must be right. After all, he spends an entire paragraph saying how no one could refute his work… until they did.

              I am so glad you made me start on chapter 11. It is truly hilarious.

            • RexTugwell

              I’m glad I made you so happy given your propensity to depression. However, you’ll pardon my skepticism about the reason for your manic phase. You’re not known for delivery the goods so far.

              I’ll tell you what I always tell my 8 year-old son: you’re a constant regret to me.

            • SmilodonsRetreat

              Wow… some parenting skills you have. So you’re just an ass to everyone then. I get it now.

              As far as the rest, you’re just sore because your golden boy Meyer is getting thoroughly trashed.

            • “given your propensity to depression”

              Listen, you piece of shit … it’s fair to make fun of each others ideas and beliefs. It is even fair to take our own words against us. It is neither fair or remotely human to use our discussions of our personal problems as fodder for this kind of “debate.” You have shown exactly what the “morality” of IDers is like and it is as ugly as I thought it might be.

            • RexTurgwell

              Whoopsie, looks like I hit a nerve in poor Mr. Pieret. Well, you piece of John, Smilodon shared with the whole world (that’s how far the Internet reaches) that he has bouts of depression. I was genuinely glad that he was so happy; however misplaced as that happiness is. You should confer with him about sharing personal info on the Internet if he doesn’t want people to reference it. Gosh!

            • I’m well aware he discussed it but why do you think it is fair or decent to bring it up in a discussion like this where it isn’t relevant at all … except as a snide attack on the person instead of the argument? I repeat, it shows more about you than it does Smiledon.

          • Your right. I didn’t go back ans check the liar’s book. Why should I? How many times do you have to check if someone is lying, once you find him lying the first time? 10, 20, 100? Been there, done that, with Smilodon’s help.

            But I did find this in your latest “sainted” chapter (after all the other chapters that were supposed to illuminate ID):

            “Nor do they directly observe the presumed mutational processes in action. At best, they provide hypothetical, after-the-fact reconstructions of a few events out of a sequence of many supposed events, starting with the existence of a presumed common ancestor gene. But that gene itself does not represent a hard data point. It is inferred to have existed on the basis of the similarity of two or more other existing genes, which are the only actual pieces of observational evidence upon which these often elaborate scenarios are based.”

            Really? Young-Earth creationist differentiations between “operational” science and “historic” science? Is that the best you and Meyer can do? I suppose you don’t believe in astronomy either, with all our inferences to reconstructions of a few events out of a sequence of many supposed events of the type and nature of stars? Maybe they are all angels lighting their farts!

            • SmilodonsRetreat

              Interesting. So Rex knows that beneficial mutations exist (you guys SERIOUSLY need to get together on what ID is supposed to be), then wonders where new genes come from… almost as if he doesn’t know anything about biology.

              It’s truly stunning.

              Let me ask this… has anyone ever seen a designer? Has anyone ever seen a design happening, being built or whatever? Has anyone seen the tools of the designer.

              “Nor do they directly observe the presumed design processes in action. At best, they provide hypothetical, after-the-fact reconstructions of a few events out of a sequence of many supposed events, starting with the existence of a presumed designer. But that design itself does not represent a hard data point. It is inferred to have existed on the basis of the complexity and non-randomness of design of two or more other existing genes, which are the only actual pieces of observational evidence upon which these often elaborate scenarios are based.”


            • Unfortunately, irony is beyond creationist understanding.

            • Doc Bill

              Creationists, and (I’m always astounded) especially the Disco Tute never read what they write, or if they do it has to be interpreted “in the moment.”

              From your Meyer quote is this little gem: “But that gene itself does not represent a hard data point. It is inferred to have existed”

              Oooooh, it’s not a hard data point. I guess science needs hard data points. It’s “inferred” in this instance pejoratively! Infer, bad!

              So, what has Meyer himself, and Dembski, and Behe written about ID over and over again? That ID has no hard data points. Meyer writes that, I believe, in Chapter 12. ID is “an inference from design in nature.”

              But, wait, wait! Meyer just said “hard data good, inference bad.” Can’t have it both ways, creationists!

              That’s what I find so pathetic about Rexy Wexy and his fellow tribe of creationists. Not only do they no clue about science, they also have no clue about creationism or “intelligent design” creationism.

          • Nerdsamwich

            It’s not that anyone lacks the courage to read your favoritest book evar. It’s that we don’t have the patience to read crap.

    • SmilodonsRetreat

      Again, YOU need to get with fellow creationists and work out exactly what you guys think. It’s not my fault that other creationists disagree with you.


      In detail, explain to us (doing something that no other creationist has ever done) WHAT ARE THE LIMITS OF EVOLUTION??

      Where do we draw the line and how do you know?

      If you can write this up with evidence to support it, I will give you a guest post spot on my blog. Oh, and be sure to explain why the only thing that happens is speciation, in your detailed response.

      1) What is the limit
      2) Where is the line
      3) How do you know
      4) What evidence supports you (remember, positive supporting evidence, not “We’ve never seen it”)

      Oh, and if you can’t understand the difference between designed lab experiments and intelligent design as a concept, then you really have no business talking to anyone about science. I’ve dealt with that before on this very blog dozens of times. If you continue to use that, then you are exposing your ignorance of science.