The less I know

Come look she said, and introduced me to Trametes versicolor.Β  Its color pattern so closely resembles that of its distant relation that the fungus is known by the common name, Turkey Tail.


What struck me when I first looked at Trametes was its color and, as I prepared the image to post here, I was again struck by its shades of azure blue. As best as I can determine, blue color, among the basidiomycete fungi, is caused by thelephoric acid, a pigment which belongs to a chemical family called the terphenylquinones.

The color blue is common in plants and, in that group, is caused by a family of pigments called the anthocyanins.


And, what of the color blue among the animals? Certainly we all have our favorite example, and mine is the Blue Bird. I am fascinated by the fact that although the color blue is found among the animals, blue pigment is not. So, this begs the question, how can animals be blue in the absence of blue (pigment)? The answer is found in what is called Structural Color, a phenomenon in which arrays of surface nanostructures scatter light and then reflect particular wavelengths to be seen by you and me. Transparent nanostructures may be found on the wings of some butterflies. These scatter light in a way that reflects just blue wavelengths. While such structures among insects are made of chitin, some bird feathers are known to be modified with keratinous barbs that also function to scatter light in a way that makes surfaces on which they are found appear blue.


In an impressive bit of work, engineers constructed tiny capsules, each containing a suspension of small particles in water. Drying the capsules caused the particles to move together. Differences in drying caused differences in the average distance between the particles which resulted in differential light scattering and in different reflected (structural) colors. Here is a photomicrograph of capsules engineered to produce blue, green, and red structural color. [Park, Jin-Gyu, Shin-Hyun Kim, Sofia Magkiriadou, Tae Min Choi, Young-Seok Kim, and Vinothan N. Manoharan, 2014. Full-spectrum photonic pigments with non-iridescent structural colors through colloidal assembly. Angew. Chem. Int. Ed., 53, 2899-2903.]
Permit me to end now with the, only slightly augmented, words of Michael Franti, The more I see (and learn), the less (I realize that) I know. It’s really true.

20 thoughts on “The less I know

  1. And your assertion about the more you learn the less you realize you know is one of the best watch-phrases for all of us. Rings so very true for me too, in so many, many ways. Let me mention just one. Back in 1978 when i first started university I knew then I wanted to do education and Physics, which i proceeded to do and have no regrets whatsoever about it. Physics, though., was such a revelation. I started that subject because I really wanted to know exactly what was going on. In short, I was a naive realist. I soon discovered–over the first 3-4- years there–that that discovery would never happen. Once I learned about the quantum world. that was it for reality. Disconcerting, to say the least. Now, almost 40 years later, knowing so very much more about the subject, I am no more enlightened, less probably. What odds–the search has been fun.

  2. I have been reading about spectral dimension these past couple days. One of my instructors in mathematics is researching this, and has extended an invitation to discuss. I hadn’t even begun to think about the topic beyond physics/math concerns yet, so this is very nice to have your biologist’s perspective to influence my thinking and add depth to my considerations at my introduction to the topic.

    • Glad to have been able to provide a bit of inspirational/motivational spark! I was going to ask, ‘How are you,’ but from the little that I can gather from your comments … you are doing just fine! I am glad.

        • You are right, we are enjoying it here. Change has been good, and we now recognize that it was long, long, overdue. I am well and not working, at the moment. After more than 30 years in the business of higher education, and having never had a sabbatical … I have decided to take this year off. I’ll think about what comes next … later.

  3. Very interesting, thanks! I haven’t heard about Structural Color before!

    I wonder why evolution has ‘picked’ these nano-patterns rather than pigments? Are they easier to ‘grow’ / ‘build’? Because you can change color by just changing the distance of the structures via having to ‘find’ another substance (for a pigment) with proper absorption characteristics?

    • That was, in fact, something I wanted to talk about in the post, but chose not to. I have a continual battle with myself concerning writing about the topic of evolution. Although I am a strong supporter of all ideas concerning the phenomenon and taught them and wrote about them, professionally, for more than 30 years … I hesitate to discuss them here at the blog. I hesitate because I fear offending those who wouldn’t appreciate my alternate hypotheses concerning explanations for why things are the way they are. If I were to discuss such a thing, and in specific regard to the point you made in your comment. The fact that (evolutionarily speaking) fungi, plants, and animals have all ‘discovered’ a different solution to the ‘problem’ of color is exactly the sort of prediction that evolutionary thinkers would make. Because these organisms occupy distinct lines, and evolved independently, you would expect unique solutions to the same problem. This is a good example of convergent evolution … the same blue … different mechanism in different, unrelated, organisms.

      • Thanks – yes, that sounds very plausible and what you would expect from a process that is not… uhm… designed πŸ˜‰ in a way. If random tinkering is done, every part of the hyperspace of options should be explored somewhere in space and time.

        But I can relate to your caution and reluctance to promote something that may seem controversial. I think nobody ever convinced anybody else of anything on the internet. Very opinionated writers preach to the choir. The more time I spent on social media the more tired I got of arguments and opinions – even if I just have to scroll past them. There are many things ‘energy-related’ that might be interesting to write about but would trigger arguments I have no energy or desire to contribute to. Like all kinds of pseudo-science and home-grown perpetuum mobiles, controversies about the effects of electromagnetic radiation or if wind turbines kill many birds (both physics and statistics involved), or energy politics in general (or politics in general). My recent post on ‘powering your home by cycling’ was an exception and I feared for the worst when I clicked Publish.

        • In your second sentence you hit upon one of my favorite topics … ‘the hyperspace of options.’ I have had some wonderful discussions, in the past, about theoretical hyper-volumes (evolutionary/morphological ones) and actual ones. Everything is probable, but a limit set of those probabilities is actually possible … and of the possible, the actual are simply the luck ones to have been drawn in that great lottery we call Mendelian Genetics! Thanks for allowing me to lecture … just a little bit! D

    • Yes. I tried to copy-n-paste a metallic blue beetle for you here but couldn’t get it to work. So, you’ll have to use your imagination this morning! Thanks for reading, for your continued interest, and for the kind comment. D

  4. Glad you continue to learn as this blog grows. You teach and we get a beautiful image in the bargain. You make fungus look like art! Love the swirly nature of this species. Love the blue jays and cardinals flitting about my yard. Signs of spring abound! Yippee!

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