- #1
grisly
- 7
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So, I was reading this comic book...
... not the most promising start for a science thread, I know, but I promise it's getting better from here!
I'm going to include a little background on the work in question in an addendum, but get straight to the point for now: The book features a group of ceratosaurs, and, I presume to make them more visually interesting, the author decided to give them an adaptive camouflage capability, as found in some present-day animals, of which the chameleon is probably the best-known example. As far as I'm aware, there is no paleontological basis for this species having such an ability - but that's neither here nor there, as far as this thread is concerned.
Below, a selection of panels showcasing the extent to which the book takes this:
- The bottom panel shows one member of the group (dubbed "Big Nose" in the dramatis personae) in its un-camouflaged state, I think.
- On the top left, we have the lot of them adapted to a uniformly coloured terrain. So far, so unspectacular.
- On the top right, we have them adapting to the sauropod carcass they were approaching in the previous panel. In addition to colour matching, we now have pattern matching, and not just in general terms, but in the sense that individual features of the carcass's skin are continued across the bodies of the scavengers. That seems a lot more remarkable to me.
- In the panoramic panel below that, we're getting into "Where's Waldo" territory (if the fifth member of the group is in it, I've not found it yet). More to the point, even the animals which are out in the open are well-camouflaged, by again continuing individual features of the backdrop across their bodies. There is an important difference from the earlier case, though: This effect now partly depends on the position of the observer. If you mentally move the "camera angle", the brown stripes cease to line up with the tree trunks they're meant to match, et cetera.
- The next panel down illustrates this more simply and clearly: The lower half of the body matches the trunk in the foreground, the upper half the greenery in the background, so that no part breaks the outline of said trunk, as long as the observer remains in the same horizontal plane as the dinosaur.
My question, as already implied, isn't about this species of dinosaur. It's how much of this is plausible, in a general sense, and, if plausible, how it works, based on what we know of this ability in present-day animals. By "how it works", I don't mean how an animal's skin can change colour, that part seems relatively straightforward. I mean how does the animal "decide" which colour to use where to achieve the desired effect.
One of the "James Bond" movies features adaptively-camouflaging cars, and the idea behind that one was also relatively straightforward, IIRC: Put cameras in various spots on the surface, and display whatever those detect at a spot on the opposite side. The higher the resolution (the more cameras and displays), the better the result. The biological equivalent of cameras are eyes, though, and most animals, including those who practice adaptive camouflage, only have two of those, so that can't be how they do it. (Or can it?)
The most remarkable example of pattern-matching I came across during my preliminary research is this picture of a peacock flounder in a tank with a checkered floor:
It's not perfect, but clearly this goes beyond merely reproducing the pattern in a generic sense, as would usually suffice for a naturally-occurring seafloor. Some of the squares are directly continued onto the body (the middle one along the bottom-left edge is especially well-done), and the top-left-to-bottom-right diagonal going right along the long axis shows an astonishingly close match to what's underneath - the shapes themselves, the sizes, the orientation, the number, everything is roughly right. Wow. Having seen this, I have no problem accepting the comic's carcass sequence as plausible.
So, how do you imagine it works? The wikipedia article mentions that "if one of the flounder's eyes is damaged or covered[, it has] difficulties in matching [its] surroundings", which confirms the role of vision as providing the input. How much processing is needed to translate that input into an output (a set of selections of particular colours for particular portions of the animal's body)? To put it in another way, if humans had this ability, would this be more akin to, say, moving one's hand to pick up something one sees lying on a table - something anyone can do without thinking about it - or more akin to painting a landscape - something that involves both thought and skill?
However much processing the checkerboard example involves, the observer-specific examples depicted in the latter panels would surely involve several orders of magnitude more. Anyone know of any real-life examples there? Cephalopods show some extraordinary abilities in a different kind of camouflage, that of masquerading as a different animal, which I imagine also involves a great deal of thought and skill, so that seems like one promising place to look.
Right, I think that's all I have so far. Looking forward to your contributions, however speculative! :)
___
Addendum: The panels are from the 1996 volume "The Hunt" of the irregularly published title "Age of Reptiles". It's written and drawn by Ricardo Delgado and coloured by James Sinclair (meaning that both creators had a hand in how the camouflage ends up looking on the page), and published by Dark Horse. The stories feature nothing but non-anthropomorphic dinosaurs in their natural habitat, so there's no text and only a very rudimentary plot; most of the storytelling consists simply of portraying animals acting the way (the author images) such animals do.
... not the most promising start for a science thread, I know, but I promise it's getting better from here!
I'm going to include a little background on the work in question in an addendum, but get straight to the point for now: The book features a group of ceratosaurs, and, I presume to make them more visually interesting, the author decided to give them an adaptive camouflage capability, as found in some present-day animals, of which the chameleon is probably the best-known example. As far as I'm aware, there is no paleontological basis for this species having such an ability - but that's neither here nor there, as far as this thread is concerned.
Below, a selection of panels showcasing the extent to which the book takes this:
- The bottom panel shows one member of the group (dubbed "Big Nose" in the dramatis personae) in its un-camouflaged state, I think.
- On the top left, we have the lot of them adapted to a uniformly coloured terrain. So far, so unspectacular.
- On the top right, we have them adapting to the sauropod carcass they were approaching in the previous panel. In addition to colour matching, we now have pattern matching, and not just in general terms, but in the sense that individual features of the carcass's skin are continued across the bodies of the scavengers. That seems a lot more remarkable to me.
- In the panoramic panel below that, we're getting into "Where's Waldo" territory (if the fifth member of the group is in it, I've not found it yet). More to the point, even the animals which are out in the open are well-camouflaged, by again continuing individual features of the backdrop across their bodies. There is an important difference from the earlier case, though: This effect now partly depends on the position of the observer. If you mentally move the "camera angle", the brown stripes cease to line up with the tree trunks they're meant to match, et cetera.
- The next panel down illustrates this more simply and clearly: The lower half of the body matches the trunk in the foreground, the upper half the greenery in the background, so that no part breaks the outline of said trunk, as long as the observer remains in the same horizontal plane as the dinosaur.
My question, as already implied, isn't about this species of dinosaur. It's how much of this is plausible, in a general sense, and, if plausible, how it works, based on what we know of this ability in present-day animals. By "how it works", I don't mean how an animal's skin can change colour, that part seems relatively straightforward. I mean how does the animal "decide" which colour to use where to achieve the desired effect.
One of the "James Bond" movies features adaptively-camouflaging cars, and the idea behind that one was also relatively straightforward, IIRC: Put cameras in various spots on the surface, and display whatever those detect at a spot on the opposite side. The higher the resolution (the more cameras and displays), the better the result. The biological equivalent of cameras are eyes, though, and most animals, including those who practice adaptive camouflage, only have two of those, so that can't be how they do it. (Or can it?)
The most remarkable example of pattern-matching I came across during my preliminary research is this picture of a peacock flounder in a tank with a checkered floor:
It's not perfect, but clearly this goes beyond merely reproducing the pattern in a generic sense, as would usually suffice for a naturally-occurring seafloor. Some of the squares are directly continued onto the body (the middle one along the bottom-left edge is especially well-done), and the top-left-to-bottom-right diagonal going right along the long axis shows an astonishingly close match to what's underneath - the shapes themselves, the sizes, the orientation, the number, everything is roughly right. Wow. Having seen this, I have no problem accepting the comic's carcass sequence as plausible.
So, how do you imagine it works? The wikipedia article mentions that "if one of the flounder's eyes is damaged or covered[, it has] difficulties in matching [its] surroundings", which confirms the role of vision as providing the input. How much processing is needed to translate that input into an output (a set of selections of particular colours for particular portions of the animal's body)? To put it in another way, if humans had this ability, would this be more akin to, say, moving one's hand to pick up something one sees lying on a table - something anyone can do without thinking about it - or more akin to painting a landscape - something that involves both thought and skill?
However much processing the checkerboard example involves, the observer-specific examples depicted in the latter panels would surely involve several orders of magnitude more. Anyone know of any real-life examples there? Cephalopods show some extraordinary abilities in a different kind of camouflage, that of masquerading as a different animal, which I imagine also involves a great deal of thought and skill, so that seems like one promising place to look.
Right, I think that's all I have so far. Looking forward to your contributions, however speculative! :)
___
Addendum: The panels are from the 1996 volume "The Hunt" of the irregularly published title "Age of Reptiles". It's written and drawn by Ricardo Delgado and coloured by James Sinclair (meaning that both creators had a hand in how the camouflage ends up looking on the page), and published by Dark Horse. The stories feature nothing but non-anthropomorphic dinosaurs in their natural habitat, so there's no text and only a very rudimentary plot; most of the storytelling consists simply of portraying animals acting the way (the author images) such animals do.