One of the most disturbingly creepy things I've realized is when looking at render of a laser scanned environment. The oddly bumpy and uneven gray mass that everything show up as. That is actually reality. The filtered colorful smooth version we see is an arbitrary specific wavelength interpretation that our brains developed. We are actually living in that creepy gray horror movie render of the laser scan.
Having worked extensively at several companies in the 1990s trying to bring optical measurement of objects into production environments, I assure you that a lot of that bumpiness turns out to be artifacts of the measurement process.
As just one example, there's really no laser-based measuring device in the world, even today, that can rapidly measure a surface near (<1mm) the edge of an object. Something that is trivial to do with ruby-ball touch sensors...
Well, but you can't pass through a solid object, right? There's a real "thing" there, it's not just a specific wavelength.
I realize "thing" is doing a lot of work in the above sentence, and that everything is all just particles. Still, I think there's something to the idea that form and shape are more real than color.
> Well, but you can't pass through a solid object, right? There's a real "thing" there, it's not just a specific wavelength.
FWIW the "solid" object you're observing is mostly space and the "you can't pass through a solid object" as far as we know is just a probability not a certainty.
If you want to go all misanthropic, it is much closer to reality to say that we see only a small slice of what is in fact a world colorful and detailed beyond all human ability to comprehend any but a small slice of it. The "creepy gray horror movie render" is the farthest thing from the truth, not the nearest.
There is reality, then there are views/models of reality constructed via various different ways of sensing reality, whether that's a laser-scan depth map, normal human 3-color vision, occasional human 4-color vision, animal UV-sensitive vision, mass detectors, magnetic/electrical field detectors, etc, etc.
Why should we regard one extremely arbitrary way of sensing reality as more important or real than any of the others? Why is reflected light important, not absorbed light? Why visible spectrum vs other frequencies? Why human red/green/blue color cone detection (which is no such thing - they are overlapping curves of frequency spectrum sensitivity)? Why focus on light reflection, not sound? Why focus on surface attributes of objects such as "color" rather then regard other attributes such a mass distribution, or anything else as primary?
No, it is just yet another incomplete view of reality. For example, where are the infrared wavelengths in that scan? How can you say "that is reality" if it doesn't include that information? You might argue there are no true views of reality, that all views of reality are only some incomplete interpretation of it.
We see only some minimal set of what is necessary for us to see in order to survive with just enough certainty that we haven't gone extinct.
It goes beyond, your brain will also add an emotional bias on certain patterns depending on how it fit our needs of the time.
Anecdotally it's quite "magical" that nature ended up as 80% beautiful landscape (and sometimes the occasional horrendous sight) as if beauty is an emergent property of the biosphere..
To generate a natural-color image of a biological sample using lasers in the human eye's visible light range, you'd need a great many lasers covering the entire frequency range. This generates hundreds of datasets at each particular wavelength (ignoring issues like laser-induced fluorescence, which can be managed with spectral filtering).
The trick comes in taking all that data from the hundreds of images generated by different-wavelength lasers and assembling them layer-by-layer into an image the human brain interprets as color, aka colorimetric rendering, onto the three-color-cone system the eye's retina employs plus a bunch of neural processing (there's a complex equation for this mapping of 'hyperspectral cube' data onto an RGB display for human visualization).
There's a really strange example - the mantis shrimp - that used to be thought to have rich color vision in a narrow band, but now people think it might be a lot more direct, a kind of color vision without much neural processing involved, with each photoreceptor scanning slighty different wavelengths and directly signalling to the mantis brain, such as it is:
Thoen et al. (2014) – "A different form of color vision in mantis shrimp" (Science)
Video on the internet was not a popular thing until we had broadband internet. Similarly it took millions of years for evolution to capitalize on the much broader bandwidth of color vision. I don't even want to know what will happen when we acquire infrared and uv vision
With the evolution of tech that enables viewing past visible light, humans have been able to find new ways of diagnosing and treating conditions that were just “bandaged over” a mere 200-300 years ago.
>Video on the internet was not a popular thing until we had broadband internet.
I think it's an example of a post hoc fallacy. The popularity of video was in large part responsible for the investment into broadband in the first place.
Yes, I read that pollinators see flowers very well because many are very bright in UV against the background [1]. Lots or cool pictures, too, if you Google "flowers UV".
The article likely distinguishes between simply having colors versus evolving colors specifically for sexual selection - fossil evidence can show dinosaur coloration but determining behavioral purpose is much harder than observing living fish species.
You're very likely right there's no causation in that direction, but it seems entirely possible that we experience red as a vivid color in part because noticing blood is evolutionarily important.
I wonder if the median vividness of coloration of species has trended downward since full spread of humans all over the globe. The brightest birds in the tropics were relatively easy meals to procure compared to more well-camoflauged species.
A very interesting tidbit of information I’ve only learned/realized when I was already an adult, is that many otherwise plain flowers have really intricate patterns in the ultraviolet, since some insects see in that spectrum.
It seems obvious to me that colors came before color vision. Natural selection constrains diversity along the axes that it selects for, while genetic mutations supply diversity along all axes simultaneously. The net result would, intuitively for me, be that nature must have had the colors before anyone could see them, since there was no reason to constrain having colors.
We'll see if that ends up being anywhere close to correct.
I think you're right. A specific example would be chlorophyll. Chlorophyll is green, not because green was selected for. Instead, it's just a side effect of the biochemistry needed to absorb energy from sunlight.
It’s not impossible that the mechanism was selected for maximizing energy absorption within the sunlight’s spectral distribution, depending on which of these curves is most relevant (e.g. incidentally the green curve): https://commons.wikimedia.org/wiki/File:Spectral_Distributio...
Leaves aren't even very green, if you look at the full spectrum of sunlight. They only reflect around 10% of green light, while they are more like 90% reflective in the infrared. So you could say that leaves are infrared. It's only our eyes' receptors that see them as green, since they are not sensitive to infrared. (And they are, for most plants, not a very bright green.)
Green is what is reflected, not absorbed. And green is higher-energy than red, so naively one would expect that plants should rather reflect red than green. However, I tried to point out with the link that things might not be that simple; though I really don’t know.
I wouldn't call that a side effect, because it is most likely a must-have feature and plants were selectively pressured on that (although I know some plants or trees have red to dark red leaves).
But yes. Logically, things have a natural color. Then animals progressively acquired the ability to distinguish colors because it was advantageous - for instance to spot a naturally brown yummy insect on a naturally green leaf.
From there, one can imagine an amplification or reinforcement process induced by co-evolution: plants take advantage of the fact that animals can see colors, animals take advantage of the fact that healthy plant produce fruits of a specific color. It eventually turned into an armed race at times: TFA opens with the example of a blue belly lizard, but one cannot help but think about chameleons.
It was probably unavoidable as soon as something like a photo-sensitive cell appeared. And it is also probably the same thing with perceptions that are less obvious to us, such as odors, sounds, or vibrations (other than of air or water - although I wouldn't be surprised if hearing evolved from that point).
Animals with camouflage coloration don't need to be able to see that color themselves. They can find each other with chemical signals and sound while hiding from their predators.
Why? I can imagine other chemical compounds with different colors that perform the same function just with a greatly reduced efficiency.
If there isn't any evolutionary competition then there could have been a long period of time before plants with chlorophyll started being produced and then dominating the landscape.
"To be clear, there was color in the world before color vision. Plant leaves, for example, reflect green light even if there are no eyes to see it."
But also keep in mind that green plants are just the ones that won, there are other chemistries with colors that work nearly as well (particularly purple, which is still present on some plants).
That's assuming the only purpose of color vision is to see the colors of other living organisms.
There's color in nature beyond life, such as in minerals and other chemicals. There's also color in life that isn't necessarily meant to convey something —such as the green of plants or the red in blood— that could be useful for finding food, for example. Interestingly, hemoglobin seems to have come to be > 400 mya too [1].
Moreover, color can help with contrast in vision. Two materials could reflect the same amount of light, but in different wavelengths.
Sure, color corresponds to a physical property, so obviously there were things of different colors (sunlight, water, rainbows, rocks) before life developed. Everything has a color.
Color vision (or just ability to differentiate 2 or more frequencies of light) could have evolved a soon as there were forms of life for who this was advantageous - potentially as simple as an ocean organism orientating itself towards sunlight.
It seems the co-evolution of the property of color and color detection ability in plant and animal species, must logically have followed a basic ability to differentiate non-evolved natural colors.
You are assuming that a random mutation will cause all colors to be equally likely. But, AIUI, there is a reason that all your standard chemical powders in a normal chemistrly lab are white; colors are a rare side effect of certain molecular properties. Most chemicals, variated randomly, are extremely boring colors, mostly white.
Almost. Reflectance is how we quantify an object's ability to absorb and reflect light. This is the physical reality, unconstrained by biology. Color is a sensation; how we perceive the reflectance based on our trichromatic vision.
It turns out I didn't grasp what the authors meant by "colorful signals". They're talking specifically about vivid colors that serve an evolutionary purpose, and in that case it seems rather clear that vision would have to come first. That is in fact also what turns out to be the findings.
While the article is a fun and light read about some scientists doing some literature review to try and approximate when color as a signal evolved, I'm afraid the error bars are so large it's hard to find any certainty.
The article does end with some speculation that vivid color can't actually evolve without eyes that produce a natural selection bias, since vivid color takes effort to construct. That claim of course has the same efficacy problems as what the article is mainly dealing with, but I do find it somewhat convincing, and have lowered my certainty that vivid colors actually evolved first.
Thanks for your thoughtful comments. I'm inclined to think colour occurred first, but there is of course no way to be sure. From our point in geological time, this is a good test of our knowledge and methods, but we are missing a significant amount of data. Several major extinction events precede us.
From TFA:
"Color vision likely evolved twice independently, [Wiens ] found, and around the same time: between 400 million and 500 million years ago in arthropods, such as insects, and in backboned animals, such as fish. That places the evolution of color vision 100 million or 200 million years before any color signals."
At least twice...
"Wiens and Emberts’ data supports the hypothesis that color evolved for some as-yet-unknown reason before any of these flashy signals. “It was color vision first, then fruit, then flowers, then warning signals and then sexual signals,” Wiens said."
Angiosperm ancestors occurred more than 300 mya [1]. Insects are older [2]. When insects and flowers evolved the commensal relationships that we know so well today, the ensuing population growth and diversification is termed an "explosion" for good reason.
Tigers and such feel like a good counter example to colors needing eyes to see them? Specifically, the color of tigers is largely evolved against eyes that don't see the orange.
As such, many colors would be expected in environments that don't confer an advantage to colors. And once an environment starts to give advantage, you would expect rapid convergence.
Which, maybe I'm just reinforcing old learning of mine? Moths were a specific way of teaching evolution in my grade school, and they acted exactly as I just described. With soot covered areas growing rise to black colorings and cleaner air giving rise to the opposite.
Calvin and Hobbes addressed this:
https://www.reddit.com/media?url=https%3A%2F%2Fpreview.redd....
One of the most disturbingly creepy things I've realized is when looking at render of a laser scanned environment. The oddly bumpy and uneven gray mass that everything show up as. That is actually reality. The filtered colorful smooth version we see is an arbitrary specific wavelength interpretation that our brains developed. We are actually living in that creepy gray horror movie render of the laser scan.
Having worked extensively at several companies in the 1990s trying to bring optical measurement of objects into production environments, I assure you that a lot of that bumpiness turns out to be artifacts of the measurement process.
As just one example, there's really no laser-based measuring device in the world, even today, that can rapidly measure a surface near (<1mm) the edge of an object. Something that is trivial to do with ruby-ball touch sensors...
Does it mean repeated scans of the same objects show different bumps?
Follow-up question, can one get rid of the bumps with standard signal filtering techniques, or even averaging different scans together?
No. We live in a world full of wavelengths. Our brains are giving us a way to see them.
The laser scan is further from the truth of reality than vision as it has less information about reality captured & displayed.
Well, but you can't pass through a solid object, right? There's a real "thing" there, it's not just a specific wavelength.
I realize "thing" is doing a lot of work in the above sentence, and that everything is all just particles. Still, I think there's something to the idea that form and shape are more real than color.
> Well, but you can't pass through a solid object, right? There's a real "thing" there, it's not just a specific wavelength.
FWIW the "solid" object you're observing is mostly space and the "you can't pass through a solid object" as far as we know is just a probability not a certainty.
Not particles, fields
Nobody tells you, but it's fields. It's always fields.
always_has_been.png
> We live in a world full of wavelengths. Our brains are giving us a way to see them.
Nitpick, but if we're talking about the world full of wavelengths, our brain gives us many ways to experience them!
You mean perceive, like an insect bobbing up and down in the corner of a swimming pool?
This.
If you want to go all misanthropic, it is much closer to reality to say that we see only a small slice of what is in fact a world colorful and detailed beyond all human ability to comprehend any but a small slice of it. The "creepy gray horror movie render" is the farthest thing from the truth, not the nearest.
Donald Hoffman, The Case Against Reality: <https://www.youtube.com/watch?v=4HFFr0-ybg0>
You could argue that the grey blob or an incomprehensible kaleidoscope of overwhelming info are both closer to reality than what we perceive.
Anyway my point was that our color perception is arbitrary. Its all just one fact, a lightwave/photon.
And there’s only one photon, vibrating like mad, singularly unable to contemplate its own magnificence.
There is reality, then there are views/models of reality constructed via various different ways of sensing reality, whether that's a laser-scan depth map, normal human 3-color vision, occasional human 4-color vision, animal UV-sensitive vision, mass detectors, magnetic/electrical field detectors, etc, etc.
Why should we regard one extremely arbitrary way of sensing reality as more important or real than any of the others? Why is reflected light important, not absorbed light? Why visible spectrum vs other frequencies? Why human red/green/blue color cone detection (which is no such thing - they are overlapping curves of frequency spectrum sensitivity)? Why focus on light reflection, not sound? Why focus on surface attributes of objects such as "color" rather then regard other attributes such a mass distribution, or anything else as primary?
The bumpy grey mass is where the matter is.
The colors you see is what kind of light the matter reflects.
Both are real!
> That is actually reality
No, it is just yet another incomplete view of reality. For example, where are the infrared wavelengths in that scan? How can you say "that is reality" if it doesn't include that information? You might argue there are no true views of reality, that all views of reality are only some incomplete interpretation of it.
We see only some minimal set of what is necessary for us to see in order to survive with just enough certainty that we haven't gone extinct.
That’s not actually reality. It’s a facet of what form of energy is there.
It goes beyond, your brain will also add an emotional bias on certain patterns depending on how it fit our needs of the time.
Anecdotally it's quite "magical" that nature ended up as 80% beautiful landscape (and sometimes the occasional horrendous sight) as if beauty is an emergent property of the biosphere..
To generate a natural-color image of a biological sample using lasers in the human eye's visible light range, you'd need a great many lasers covering the entire frequency range. This generates hundreds of datasets at each particular wavelength (ignoring issues like laser-induced fluorescence, which can be managed with spectral filtering).
The trick comes in taking all that data from the hundreds of images generated by different-wavelength lasers and assembling them layer-by-layer into an image the human brain interprets as color, aka colorimetric rendering, onto the three-color-cone system the eye's retina employs plus a bunch of neural processing (there's a complex equation for this mapping of 'hyperspectral cube' data onto an RGB display for human visualization).
There's a really strange example - the mantis shrimp - that used to be thought to have rich color vision in a narrow band, but now people think it might be a lot more direct, a kind of color vision without much neural processing involved, with each photoreceptor scanning slighty different wavelengths and directly signalling to the mantis brain, such as it is:
Thoen et al. (2014) – "A different form of color vision in mantis shrimp" (Science)
https://www.science.org/doi/10.1126/science.1245824
What we see doesn't exist and we what exist we cannot see.
Video on the internet was not a popular thing until we had broadband internet. Similarly it took millions of years for evolution to capitalize on the much broader bandwidth of color vision. I don't even want to know what will happen when we acquire infrared and uv vision
Flowers will happen. Most “white” flowers actually have landing strips painted on them in ultraviolet.
With the evolution of tech that enables viewing past visible light, humans have been able to find new ways of diagnosing and treating conditions that were just “bandaged over” a mere 200-300 years ago.
>Video on the internet was not a popular thing until we had broadband internet.
I think it's an example of a post hoc fallacy. The popularity of video was in large part responsible for the investment into broadband in the first place.
Unlike evolution, humans can think ahead.
A big driver for investment was the idea of 'internet tv'. Remember MSN TV?
A lot of insects can see in UV.
Edit: interesting article here- https://en.m.wikipedia.org/wiki/Ultraviolet_communication_in...
Yes, I read that pollinators see flowers very well because many are very bright in UV against the background [1]. Lots or cool pictures, too, if you Google "flowers UV".
[1] https://en.wikipedia.org/wiki/UV_coloration_in_flowers
Did they purposely ignore dinosaurs? Feathered dinosaurs are known to be colorful
https://www.reuters.com/article/world/chinese-rainbow-dinosa...
Hard to believe their claim fish are the first to evolve color for mating displays 100 million years ago.
> Feathered dinosaurs are known to be colorful
Perhaps because it's not truly known.
> The discovery "suggests a more colourful Jurassic World than we previously imagined,"
-- from your link
The article likely distinguishes between simply having colors versus evolving colors specifically for sexual selection - fossil evidence can show dinosaur coloration but determining behavioral purpose is much harder than observing living fish species.
Bacteria can be colorful. It can also fluoresce.
My blood is red because it has iron in it not because there's an evolutionary link to my eyesight.
You're very likely right there's no causation in that direction, but it seems entirely possible that we experience red as a vivid color in part because noticing blood is evolutionarily important.
>> Plant leaves, for example, reflect green light even if there are no eyes to see it
It seems that the logical colour for a leaf would be completely black - absorbing all energy. Fortunately that isn't how it worked out.
Well then leaves would get too hot and plants can’t absorb unlimited sun
They need to absorb red and blue light
Right but Dyson sphere isn't green I don't think.
I wonder if the median vividness of coloration of species has trended downward since full spread of humans all over the globe. The brightest birds in the tropics were relatively easy meals to procure compared to more well-camoflauged species.
> They have evolved even in species that don’t have color vision, likely because their predators do.
I mean, that shouldn't be too surprising since plants don't have vision at all and still evolved colors.
A very interesting tidbit of information I’ve only learned/realized when I was already an adult, is that many otherwise plain flowers have really intricate patterns in the ultraviolet, since some insects see in that spectrum.
Before reading:
It seems obvious to me that colors came before color vision. Natural selection constrains diversity along the axes that it selects for, while genetic mutations supply diversity along all axes simultaneously. The net result would, intuitively for me, be that nature must have had the colors before anyone could see them, since there was no reason to constrain having colors.
We'll see if that ends up being anywhere close to correct.
I think you're right. A specific example would be chlorophyll. Chlorophyll is green, not because green was selected for. Instead, it's just a side effect of the biochemistry needed to absorb energy from sunlight.
It’s not impossible that the mechanism was selected for maximizing energy absorption within the sunlight’s spectral distribution, depending on which of these curves is most relevant (e.g. incidentally the green curve): https://commons.wikimedia.org/wiki/File:Spectral_Distributio...
Leaves aren't even very green, if you look at the full spectrum of sunlight. They only reflect around 10% of green light, while they are more like 90% reflective in the infrared. So you could say that leaves are infrared. It's only our eyes' receptors that see them as green, since they are not sensitive to infrared. (And they are, for most plants, not a very bright green.)
That's what I'm getting at. Green was needed to optimize energy absorption from the sun. AFAIK, there are no other advantages to selecting for green.
Green is what is reflected, not absorbed. And green is higher-energy than red, so naively one would expect that plants should rather reflect red than green. However, I tried to point out with the link that things might not be that simple; though I really don’t know.
I wouldn't call that a side effect, because it is most likely a must-have feature and plants were selectively pressured on that (although I know some plants or trees have red to dark red leaves).
But yes. Logically, things have a natural color. Then animals progressively acquired the ability to distinguish colors because it was advantageous - for instance to spot a naturally brown yummy insect on a naturally green leaf.
From there, one can imagine an amplification or reinforcement process induced by co-evolution: plants take advantage of the fact that animals can see colors, animals take advantage of the fact that healthy plant produce fruits of a specific color. It eventually turned into an armed race at times: TFA opens with the example of a blue belly lizard, but one cannot help but think about chameleons.
It was probably unavoidable as soon as something like a photo-sensitive cell appeared. And it is also probably the same thing with perceptions that are less obvious to us, such as odors, sounds, or vibrations (other than of air or water - although I wouldn't be surprised if hearing evolved from that point).
Animals with camouflage coloration don't need to be able to see that color themselves. They can find each other with chemical signals and sound while hiding from their predators.
> it is most likely a must-have feature
Why? I can imagine other chemical compounds with different colors that perform the same function just with a greatly reduced efficiency.
If there isn't any evolutionary competition then there could have been a long period of time before plants with chlorophyll started being produced and then dominating the landscape.
The article mentions this:
"To be clear, there was color in the world before color vision. Plant leaves, for example, reflect green light even if there are no eyes to see it."
But also keep in mind that green plants are just the ones that won, there are other chemistries with colors that work nearly as well (particularly purple, which is still present on some plants).
That's assuming the only purpose of color vision is to see the colors of other living organisms.
There's color in nature beyond life, such as in minerals and other chemicals. There's also color in life that isn't necessarily meant to convey something —such as the green of plants or the red in blood— that could be useful for finding food, for example. Interestingly, hemoglobin seems to have come to be > 400 mya too [1].
Moreover, color can help with contrast in vision. Two materials could reflect the same amount of light, but in different wavelengths.
[1]: https://www.ox.ac.uk/news/science-blog/ancient-blood-lines-t...
Sure, color corresponds to a physical property, so obviously there were things of different colors (sunlight, water, rainbows, rocks) before life developed. Everything has a color.
Color vision (or just ability to differentiate 2 or more frequencies of light) could have evolved a soon as there were forms of life for who this was advantageous - potentially as simple as an ocean organism orientating itself towards sunlight.
It seems the co-evolution of the property of color and color detection ability in plant and animal species, must logically have followed a basic ability to differentiate non-evolved natural colors.
You are assuming that a random mutation will cause all colors to be equally likely. But, AIUI, there is a reason that all your standard chemical powders in a normal chemistrly lab are white; colors are a rare side effect of certain molecular properties. Most chemicals, variated randomly, are extremely boring colors, mostly white.
This tracks with life around deep sea vents where there is no sunlight. It's mostly white and gray.
Almost. Reflectance is how we quantify an object's ability to absorb and reflect light. This is the physical reality, unconstrained by biology. Color is a sensation; how we perceive the reflectance based on our trichromatic vision.
After reading:
It turns out I didn't grasp what the authors meant by "colorful signals". They're talking specifically about vivid colors that serve an evolutionary purpose, and in that case it seems rather clear that vision would have to come first. That is in fact also what turns out to be the findings.
While the article is a fun and light read about some scientists doing some literature review to try and approximate when color as a signal evolved, I'm afraid the error bars are so large it's hard to find any certainty.
The article does end with some speculation that vivid color can't actually evolve without eyes that produce a natural selection bias, since vivid color takes effort to construct. That claim of course has the same efficacy problems as what the article is mainly dealing with, but I do find it somewhat convincing, and have lowered my certainty that vivid colors actually evolved first.
Thanks for your thoughtful comments. I'm inclined to think colour occurred first, but there is of course no way to be sure. From our point in geological time, this is a good test of our knowledge and methods, but we are missing a significant amount of data. Several major extinction events precede us.
From TFA:
At least twice... Angiosperm ancestors occurred more than 300 mya [1]. Insects are older [2]. When insects and flowers evolved the commensal relationships that we know so well today, the ensuing population growth and diversification is termed an "explosion" for good reason.[1] https://en.wikipedia.org/wiki/Flowering_plant
[2] https://en.wikipedia.org/wiki/Evolution_of_insects
Tigers and such feel like a good counter example to colors needing eyes to see them? Specifically, the color of tigers is largely evolved against eyes that don't see the orange.
As such, many colors would be expected in environments that don't confer an advantage to colors. And once an environment starts to give advantage, you would expect rapid convergence.
Which, maybe I'm just reinforcing old learning of mine? Moths were a specific way of teaching evolution in my grade school, and they acted exactly as I just described. With soot covered areas growing rise to black colorings and cleaner air giving rise to the opposite.