United States of Lizardia

[lwcamp]

Originally Posted by Asta Kask

Most lizards have excellent tri-chromatic and sometimes even tetra-chromatic vision. Color-blindness is largely confined to mammals.

Not to mention that the Troodon's closest living relatives, the birds and crocodilians, also have tetrachromatic vision.

Luke

[lwcamp]

Originally Posted by StevenH

Typically, colorblind animals (and people) tend to have better contrast recognition and better night vision, both of which use the non-color bits of the eyes and visual cortex.

Are you sure about the better contrast recognition? From what I've read, color vision is associated with better detail recognition while the more colorblind the critter, the better its ability to notice motion. This jives with what I've seen of animal behavior (cats, for example, with relatively poor color vision, also don't notice details well - they need smell to locate a bit of tuna on the floor that we can clearly see).

Luke

[Michael Cule]

Presumably the USL sing songs like "Hurrah for the Gray, White and Gray" and "Hurrah for the Bonny Gray Flag that wears a single star."

"Gray Moon"

"The Greyish Rose of Texas"

I could go on. I will, in charity, now stop.

[StevenH]

Originally Posted by lwcamp

Are you sure about the better contrast recognition? From what I've read, color vision is associated with better detail recognition while the more colorblind the critter, the better its ability to notice motion. This jives with what I've seen of animal behavior (cats, for example, with relatively poor color vision, also don't notice details well - they need smell to locate a bit of tuna on the floor that we can clearly see).

Luke

Admittedly, I am not sure. It is anecdotal, from first hand experience working with two red/green colorblind coworkers. Perhaps contrast recognition is the wrong term; what would the term be that describes the ability to see gradations of grey better than others? In any case, I don't think that it an eye-based thing; it is an optical cortex thing (not having a significant chunk of the brain processing the color info, but spending more "time" on what's left.) Also note that my statistical sample is rather on the low side. What I am seeing may not be a general tendency, but statistical outliers.

So feel free to take this with a block of salt. ;-)

[Ragitsu]

Thanks for responding, guys. My internet's been down for a few days, so i'll get caught up here ASAP.

[Bruno]

Originally Posted by StevenH

Admittedly, I am not sure. It is anecdotal, from first hand experience working with two red/green colorblind coworkers.

Ah, and here is the major difference. lwcamp is thinking of animals that have evolved to live without color vision, and therefore quite possibly don't have nearly as much brainspace dedicated to things like fussy little visual details.

You're thinking about humans (with really good vision and lots of brainspace dedicated to sorting out static details) who have defective eyeballs.

With the neo-troodons having Colorblindness, but NOT another vision related disadvantage (I'd cop out with Nearsighted out of the existing GURPS ones, but it really needs a new disad like some of lwcamp's houserule ones) it suggests a model more like a human (or other normally-visually-acute creature) with colorblindness, rather than an animal adapted to colorblindness.

This will help make the neo-troodon's more "inexplicably" like humans, which fits the theme of the dimension, but makes less evolutionary sense.

My approach to the USL is that you shouldn't think too hard about evolutionary sense and rationalizing things - it's a Weird Parallel. There may not be any super powers or magic or obvious rubber physics there, but there's something Weird at work and it produces nonsensical results at times.

In other words, it's a dimension that seems, at times, maliciously designed to give scientists of all kinds splitting headaches.

[StevenH]

Originally Posted by Bruno

Ah, and here is the major difference. lwcamp is thinking of animals that have evolved to live without color vision, and therefore quite possibly don't have nearly as much brainspace dedicated to things like fussy little visual details.

You're thinking about humans (with really good vision and lots of brainspace dedicated to sorting out static details) who have defective eyeballs.

Hmmm. I had just assumed that the troodons of the USL had a large optic center in their brains, much like the human model. (And here I try to NOT do the humanocentric thing when it comes to alien design!) Just goes to show you that you really should leave your assumptions at the door and view things with a clean perspective. Thanks for pointing this out.

[lwcamp]

Originally Posted by Bruno

Ah, and here is the major difference. lwcamp is thinking of animals that have evolved to live without color vision, and therefore quite possibly don't have nearly as much brainspace dedicated to things like fussy little visual details.

You're thinking about humans (with really good vision and lots of brainspace dedicated to sorting out static details) who have defective eyeballs.

I think it also has something to do with the nature of rods versus cones. Cones see in color, rods are black and white only but better at seeing in dim light. However, I've also read that rods are naturally better at motion detection while cones have better edge detection capabilities - this is part of their pre-processing capabilities before the information gets sent along the optic nerve to the brain. I'm not 100% confident in this, so be sure to verify this information before using it for critical activities (that is, if it ever comes up as necessary info to land a plane safely or operate a nuclear power reactor, consult a real expert in the field).

Luke

[Flyndaran]

Originally Posted by lwcamp

Are you sure about the better contrast recognition? From what I've read, color vision is associated with better detail recognition while the more colorblind the critter, the better its ability to notice motion. This jives with what I've seen of animal behavior (cats, for example, with relatively poor color vision, also don't notice details well - they need smell to locate a bit of tuna on the floor that we can clearly see).

Luke

Poor example. Cats' tapetum increases the amount of usable light that hits thier retinas but has the side effect of blurring the image. No amount of color vision would clear that up.

[oldgringo2001]

"Motion-based" sight is a crock from the first Jurassic Park film, and the oversized velociraptors in all the films are never depicted as having limited vision.

Color-blindness is possible, but if the Lizards are colorblind, they should also have extremely good night vision. Troodons had very large eyes, so they were probably night hunters.

But cats also have great night vision and they can see color, which gives them more opportunities to spot prey in the daytime. The large killing claws on their feet suggest that the troodons and all the other dromeosaurs were ambushers and pouncers like almost all cats, not runners who chased down prey like hyenas or wolves. The one cat that does chase down its prey, the Cheetah, doesn't have retractable claws, and its claws are blunt, quite like a dogs, not much use as a weapon but able to dig into the dirt to provide better footing. Think built-in cleats.

I think an interesting option would be to make the males colorblind, but give the females color vision. Many female birds use color vision to judge the quality of potential mates, but males don't need it. Also, colorblindness is far more common among human males than females; whatever worked to produce this anomaly would probably duplicate it on a world with an amazingly similar history and culture to present-day (human) Earth. Colorblindness in a female, or color vision in a male, might be a Social Stigma if known, or a Secret if not.

Humans don't have full color vision. You can prove it to yourself if you have a number of similar objects in different colors--M&Ms, Skittles, or all those dice. Either close your eyes or turn your back and pick one at random. Bring it around until you can just see it at the edge of your vision, then guess the color. Repeat until you convince yourself that you really can't see colors at the edge of your vision, only near its center. Your brain is filling in the colors for the rest from memory and extrapolation.

Naked-eye astronomers know a trick to spot dim stars: Look first where you thin it is, then move your center of vision away slowly. Chances are pretty good you will now notice stars you didn't at first. The cones which give you color vision are mostly clustered around the optic nerve; the outer edges of the retina are almost completely filled with rods, which sense only relative brightness, but are more sensitive to lower levels of light. You still may not be able to see that star looking right at it, but you know where to check for it when you get a telescope, or someone invents the telescope.