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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 g

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.

delusional 1y ago
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.
- adrian_b 1y ago
  It looks like by "colorful signals" they mean colorful surfaces of animals and plants, in the case when those colors are not colors necessary for the function of some vital organ, e.g. the pigments that capture light in plants or the red iron-based or blue copper-based respiratory pigments (such pigments have appeared before vision organs).
- taeric 1y ago
  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.
- heresie-dabord 1y ago
  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. [1] https://en.wikipedia.org/wiki/Flowering_plant https://en.wikipedia.org/wiki/Flowering_plant [2] https://en.wikipedia.org/wiki/Evolution_of_insects https://en.wikipedia.org/wiki/Evolution_of_insects
xiande04 1y ago
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.
- kibwen 1y ago
  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).
- astrobe_ 1y ago
  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).
  - kevin_thibedeau 1y ago
    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.
  - 1y ago
esafak 1y ago
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.
deleted 1y ago
[deleted]
aylmao 1y ago
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-tracing-evolution-haemoglobin https://www.ox.ac.uk/news/science-blog/ancient-blood-lines-t...
- deleted 1y ago
  [deleted]
HarHarVeryFunny 1y ago
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.
teddyh 1y ago
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.
- xiande04 1y ago
  This tracks with life around deep sea vents where there is no sunlight. It's mostly white and gray.

delusional 1y ago

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.

adrian_b 1y ago
It looks like by "colorful signals" they mean colorful surfaces of animals and plants, in the case when those colors are not colors necessary for the function of some vital organ, e.g. the pigments that capture light in plants or the red iron-based or blue copper-based respiratory pigments (such pigments have appeared before vision organs).
taeric 1y ago
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.
heresie-dabord 1y ago
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. [1] https://en.wikipedia.org/wiki/Flowering_plant https://en.wikipedia.org/wiki/Flowering_plant [2] https://en.wikipedia.org/wiki/Evolution_of_insects https://en.wikipedia.org/wiki/Evolution_of_insects

xiande04 1y ago

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.

kibwen 1y ago
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).
astrobe_ 1y ago
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).
- kevin_thibedeau 1y ago
  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.
- 1y ago

esafak 1y ago

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.

deleted 1y ago

[deleted]

aylmao 1y ago

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-tracing-evolution-haemoglobin https://www.ox.ac.uk/news/science-blog/ancient-blood-lines-t...

deleted 1y ago
[deleted]

HarHarVeryFunny 1y ago

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.

teddyh 1y ago

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.

xiande04 1y ago
This tracks with life around deep sea vents where there is no sunlight. It's mostly white and gray.