tag:blogger.com,1999:blog-5821098719340852065.post6413364445909576865..comments2024-03-25T09:31:36.926+01:00Comments on Furahan Biology and Allied Matters: The eyes have it!Sigmund Nastrazzurrohttp://www.blogger.com/profile/16449461215427527447noreply@blogger.comBlogger30125tag:blogger.com,1999:blog-5821098719340852065.post-7813835644107699312021-09-30T10:44:06.356+02:002021-09-30T10:44:06.356+02:00zooshgarg: an eye that we do not recognise as an e...zooshgarg: an eye that we do not recognise as an eye would be wonderfully alien, but personally I would need an explanation of how it works: how does that eye transform incoming light into a representation of the environment of the animal? If not through a lens or through multiple lenses, how? Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-35414802317178662832021-09-30T06:43:42.603+02:002021-09-30T06:43:42.603+02:00The best compromise between "alienism" a...The best compromise between "alienism" and realism would be: what if an eye evolved-- but it doesn't look anything like what we'd recognize as an eye? The Xenomorph from the Alien movies comes to mind-- it's been theorized by some fans that the smooth carapace covering its elongated head actually functions as one big eye, allowing it to percieve its prey while still keeping the "faceless and inhuman" aspect of the iconic movie creature.zooshgargnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-54665141792570867632020-12-19T13:35:22.323+01:002020-12-19T13:35:22.323+01:00Davide: the first time I tried your link I got not...Davide: the first time I tried your link I got nothing, but this time I did. I still think that sight is much superior to echolocation, and that those rudimentary eyes might soon be more useful than echolocation.<br /><br />As for the 2020 TV series, I was asked to contribute, but did not have the time, which I found very frustrating. As that frustration might unfairly echo through in a review, I will not write one. I am glad I posted about spidrids, including ones with an odd number of legs, many years ago for all to see, so if there is ever any question of priority, the answer is clear. Their overall leg anatomy, including freedom of movements of the joints, is very similar to that of my spidrids. Their CGI is professionally done and much better than mine. Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-33512858479928208282020-12-18T19:13:50.570+01:002020-12-18T19:13:50.570+01:00Nope, I was referring to Alien Planet, the documen...Nope, I was referring to Alien Planet, the documentary based on Expedition. Through the link you should be able to see some rare high quality screenshots and some interpretative drawings that apparently show eyes.<br />But since you mentioned Alien Worlds, I noticed that the pentapodes in the second episode are somewhat similiar to your spidrids, being both radially symmetrical organisms capable of mooving in any direction. It would be really neat to know what you think about them, and of the series in general.Davide Gioiahttps://www.blogger.com/profile/00541804529581203322noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-41138477240717964752020-12-14T10:22:29.213+01:002020-12-14T10:22:29.213+01:00Davide Gioia: welcome! Are you talking about the 2...Davide Gioia: welcome! Are you talking about the 2020 documentary on alien life? I have still only seen the first episode, so I cannot comment on what you describe here yet. But if these animals live in an environment where sight is well possible, I would find it difficult to avoid sight, as you describe.Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-55986254318323888652020-12-11T17:28:19.977+01:002020-12-11T17:28:19.977+01:00My first comment!
So I've found that apparentl...My first comment!<br />So I've found that apparently in the documentary the creatures were given rudimentary eyes, though you have to wonder why they all still use ecolocation as their main sense given the superiority of vision https://mobile.twitter.com/FabioAleRomero/status/1221987305629650945 .<br />Davide Gioiahttps://www.blogger.com/profile/00541804529581203322noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-7906226481599316062012-05-24T17:11:00.095+02:002012-05-24T17:11:00.095+02:00Anonymous:
Those are good points; when considerin...Anonymous:<br /><br />Those are good points; when considering arguments for the superiority of vision of other senses, I considered hearing and sonar, and came up with a similar set of weaknesses of hearing as compared to vision. <br /> Obviously, the strengths and weaknesses do not overlap completely, which is why mutltiple senses are useful.Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-46538045317945502572012-05-24T14:18:53.697+02:002012-05-24T14:18:53.697+02:00there might be one very good reason why heat senso...there might be one very good reason why heat sensors did not evolve especially during the cambrium explosion:<br />there was nothing to detect!<br />every creature at that time had the same temperature than the surrounding environment... sure enough their muscles and metabolism produced some small amount of heat but it dispersed immediately leaving nothing to detect...<br />near infrared now is something different but why stop there if there are other wavelengths to "see"?<br />as long as they are reflected by other objects and i doubt that heat is reflected in a needed amount...<br /><br />even nowadays heat detection alone would be pretty dangerous for an agile creature because there are lots of obstacles/objects even other beasts not producing any form of infrared radiation or reflecting it which would not be "seen".<br />even modern nightvision devices use very often an infrared source to "light up" the surroundings in order to actually have something to detect.<br /><br />i just recently read an article about giant squids living in the depths of the oceans in absolute darkness... they have the biggest eyes known!<br />it is thought that their eyes are very sensitive and even detect the smallest amount of disturbance in the darkness produced by bioluminescent algae when a pray or their predator, the sperm whale is floating through the water.<br /><br />life has a tendency to use any source of information it can get hold of - any - because it is an advantage over the others!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-72758341542516639002012-02-04T14:38:30.421+01:002012-02-04T14:38:30.421+01:00Spugpow: the fact that river dolphins tend to lose...Spugpow: the fact that river dolphins tend to lose sight is a good argument that there is lower limit of visibility below which vision is not useful. <br /> The original supposition by Barlowe was that such a state could exist over an entire planet, which seems near-impossible to me.<br /><br />Mike & Rodlox: On Earth vision seems to have taken off extremely quickly. In fact, the Cambrium explosion is now thought to have been due to the rapid evolution of vision. What no-one knows is whether there were animals with echolocation before that. I doubt it. That means there is no analogue on Earth for well-established echolocation followed by the evolution of a primitive eye (as far as I know). Would a primitive eye be useful enough to keep evolving under such circumstances. I recognised that problem in my post when I wrote "I doubt eye evolution would really be held back by superior senses, already present, but that line of thought deserves further thought." The answer may lie in the relative strengths and weaknesses of vision and echolocation. That is a good subject for a post, but one that deserves study beforehand. Don't expect it any time soon...Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-44290766576923409892012-02-04T05:45:42.762+01:002012-02-04T05:45:42.762+01:00I thought of a better analogy:
vision is like ter...I thought of a better analogy:<br /><br />vision is like terrestrial locomotion.<br /><br />no matter what superior form of walking might potentially emerge from the sea, it still has to deal with the well-established and entrenched tetrapods which are already walking about.<br /><br />-Rodlox.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-88897576314203356912012-02-04T01:52:56.691+01:002012-02-04T01:52:56.691+01:00@rodlox Good point, I had thought of that, but I h...@rodlox Good point, I had thought of that, but I have some trouble believing echolocation would arise before eyes. That being said, it's not all too improbable, I could definitely see it happening now that I've thought more about it.mikenoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-11715535755472234132012-02-03T22:14:09.577+01:002012-02-03T22:14:09.577+01:00I, rodlox, do ask...
>On a planet where no lan...I, rodlox, do ask...<br /><br />>On a planet where no land organisms have eyes, the ones with eyes will surely quickly dominate<br /><br />assuming there's nothing better. on a planet where you have echolocators or electric-sensings (dolphins and electric eels, say)...exactly what advantage do you get from having a scallop or frog eye? (you can be stunned without being able to see your predator, no matter how good your eye is)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-82583950619516428302012-02-03T20:20:41.723+01:002012-02-03T20:20:41.723+01:00@spugpow
it could, but that wouldn't stop it ...@spugpow<br /><br />it could, but that wouldn't stop it from developing eyes on land. In at least one instance (pit vipers) terrestrial organisms have evolved photoreceptors. Therefore, it's plausible to presume an organism can still evolve eyes even after they've gotten on land. On a planet where no land organisms have eyes, the ones with eyes will surely quickly dominatemikenoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-90042750858767324812012-02-03T08:56:03.623+01:002012-02-03T08:56:03.623+01:00"Another argument along the same lines is tha..."Another argument along the same lines is that the range of vision under water is habitually much smaller than on dry land, but that has not stopped vision developing under water; quite the opposite. "<br /><br />Up to a point, since animals in sediment-heavy rivers tend to lose their sight. The visibility in the Amazon is something like 5 feet, so maybe that's the threshold for blindness. <br /><br />Could your animals have evolved in a small sea loaded with sediment from rivers dumping into it?Spugpowhttp://amnioticoef.deviantart.com/noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-67486254730575761512012-02-02T20:35:02.342+01:002012-02-02T20:35:02.342+01:00Aww darn. Oh well, there must be other ways to mak...Aww darn. Oh well, there must be other ways to make a life-bearing lightless environment, however uncommon they may be.<br /><br />What about a planet with an insufficient magnetic field, so it's perpetually showered in radiation? Life could develop in underground aquifers and spread into the cave systems. However I have doubts as to whether this could lead to intelligent life.<br /><br />Then there are rogue planets, but there'd be little energy, so I doubt anything could survive on one of those for long.<br /><br />Perhaps the moon of a rogue planet, the tidal forces of which lead to a great amount of tectonic activity on the moon, leading to the development of plant-like thermotrophs and complex life to prey on them. The biggest problem with this is that the thermotrophs would be highly concentrated around hotspots and wouldn't grow very tall, so the animals wouldn't grow very large either. Maybe it orbits a Y dwarf instead of a rogue planet, so it has very little light emitted in addition to the heat, so both thermotrophs and photoautotrophs exist, though not enough for the animals to see anything of worth.<br /><br />Or maybe the atmosphere is simply too clouded by carbon dioxide and other detritus, (like on venus, but without the acid storms), leading to an intense greenhouse effect, so the heat is more evenly distributed, and the "plants" are still forced to compete by growing over each other.<br /><br />Or perhaps the dark side of a tidally-locked planet, though the dark side would be supposedly too cold for life, and the light side too hot, so everything would have to live in the middle, which would still get a sufficient amount of light.Mikenoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-54099488850642226122012-02-02T13:11:07.558+01:002012-02-02T13:11:07.558+01:00Mike:
That is a very interesting question, perhap...Mike:<br /><br />That is a very interesting question, perhaps deserving of a longer discussion. I will keep it short though. You could approach it from two angles:<br /><br />The first is how poor visibility has to get to render vision useless. My guess is that a very thick fog on Earth reduces visibility to 5-10 meters. I suspect that adding even more droplets of water to the air than are present in such a fog would lead to the droplets coalescing, meaning they will drop to the ground as a drizzle. In other words, there may a limit to how dense a fog can get. <br /> Is a limit of, say, 5 meters enough to make vision worthless? For a dinosaur or an elephant that limit is less than or equal to one body length, and perhaps range of vision should be expressed in such terms. If so, a maximally dense fog negates the big advantage of vision, i.e. it is a long-range sense. However, I suspect that a range of 5 meters is perfectly adequate for small animals such as insects. I would not be surprised to learn that for them most relevant visual information comes from much closer by. <br /> Another argument along the same lines is that the range of vision under water is habitually much smaller than on dry land, but that has not stopped vision developing under water; quite the opposite. <br /> Finally, animals could evolve near-infrared to counter the effects of fog partially.<br /> Taken together, I think that a limited range of vision due to fog is not a good argument against vision evolving. No light at all is probably the only convincing argument (underneath an ice cap for instance). <br /><br />The second angle is whether permanent fog is possible or likely. Fog is a dynamic phenomenon: forming it involves saturating air with water vapour and then altering the temperature, pressure or water content so the water condenses. From this dynamic nature it seems to me that a permanent fog seems unlikely. It also seems unlikely that fog would be present all over a planet. But perhaps you can think of a situation in which life can only evolve on a small part of the planet because of specific circumstances there, and those circumstances also involve a permanent fog rolling in from elsewhere. Even so, life had better stay confined to those areas, or else there is an excellent chance for an extremely quick evolution of vision once the animals come out of the fog. <br /><br />Sorry to be a wet blanket...Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-81809380797744191312012-02-01T22:36:22.302+01:002012-02-01T22:36:22.302+01:00There's also scallop eyes, which apparently wo...There's also scallop eyes, which apparently work like a satellite dish, in that they reflect light as opposed to refract it. Jumping spiders eyes (which I think is what the creatures of fragment's eyes were based on) have a moveable sock-like retina which they stretch in different directions to change focus and look in different directions.<br /><br />With regards to the fog excuse, how much fog is enough to discredit complex eyesight, and is it an achievable amount? I ask because I designed such an alien (http://yasbp.deviantart.com/gallery/#/d4a8pki) as part of a contest, and it's one of my favorite races so far, so I really want to know if an eye-subduing perpetual mist planet is plausible enough for me to include in my project.mikenoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-16679932684664828702012-01-25T08:12:14.148+01:002012-01-25T08:12:14.148+01:00"About Fresnel lenses: even if they don't..."About Fresnel lenses: even if they don't do much to reduce overall eye volume I think they could add their own sense of 'alienness.' Perhaps the vagaries of genetic inheritance would bring this about..."<br /><br />I can imagine fresnel lenses developing from myriads of transparent scales rather than a single mass--maybe they're the route insects would take if they evolved camera-type eyes. <br /><br />Regarding compound eye resolution: perhaps the data from each eye could be compiled to create a more detailed picture, or even combined with echolocation as dolphins do to give more information about texture and density--perhaps interpreted by the visual centers as an extra "color" spectrum. Weak echolocation shouldn't be difficult to evolve; shrews do it, and even humans can with practice (could the shields of the marshwallows have a secondary role as sound-focusing structures?).<br /><br />Rodlox: Don't forget leatherback sea turtles and marlin-type fish.Spugpowhttp://amnioticoef.deviantart.com/noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-19891444959506746562012-01-24T06:26:19.534+01:002012-01-24T06:26:19.534+01:00I, rodlox, wish to add:
Moths aren't the only ...I, rodlox, wish to add:<br />Moths aren't the only ectotherms which can raise body temperature...pythons and-or boas can do the same thing to keep their eggs warm.<br /><br />Also, sharks are able to warm up the tissues surrounding their eyes.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-71978382004585028352012-01-24T01:28:15.086+01:002012-01-24T01:28:15.086+01:00'otherness' is good, but for me it might a...<i>'otherness' is good, but for me it might also mean just another culture; it does not seem as far-ranging as I would prefer.</i><br /><br />Fair enough. I actually enjoy it because of its breadth in application. To me it can apply to any sort of "other" world, from the alien grandeur of Furaha to what life is like for my neighbor, a foreigner, or my brother's dog. In a sense they're <i>all</i> alien worlds. But to each his own.<br /><br /><i>Your question about heat spots is interesting. I do not know whether their presence automatically points to endothermy.</i><br /><br />Yeah, I'm not sure either. There's a strong correlation, I think, because specialized infrared generators would likely evolve from more simple, generic heat generators or a widespread endothermy. The idea is intriguing to me, and as I researched the concept I found that moths in cold environments will 'shiver' before flight, effectively warming up their muscles so they can move their wings efficiently. I conceived of an organ (adapted from a couple hearts, so there's your circulatory loop) that would have a similar function, using friction for thermogenesis. However, discussion in the SE forums convinced me that fur and metabolic endothermy would be a more efficient design. "Mr. Heart-heaters" would have to eat a lot to fuel those organs, and they could easily give out. I'd still love to find out a way to make this idea happen, but I think I need to do more research on the matter and I'd love to explore it further.<br /><br />About Fresnel lenses: even if they don't do much to reduce overall eye volume I think they could add their own sense of 'alienness.' Perhaps the vagaries of genetic inheritance would bring this about and make for interesting and different eyes even if there's no real advantage to them. Am I wrong in this sentiment?Evan Blackhttps://www.blogger.com/profile/10493966209787828900noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-36556703154984059162012-01-24T00:09:04.431+01:002012-01-24T00:09:04.431+01:00Nine comments already? This subject seems to have ...Nine comments already? This subject seems to have caught your eye!<br /><br />Mithril: You are quite right, and I can unashamedly say that that is the very reason why most Furahan life forms have compound eyes. I have been planning to write more about them, as I suspect that compound eyes, much larger than insects' ones, coupled with subtle neural programming, should allow better resolution than mere enlargement alone (but I need more proof of that).<br /><br />Rodlox: For the purpose of being 'seen' by others it does not really matter whether heat is generated internally or externally, I would think? Or am I missing your point? <br /> ET is indeed a nice example...<br /><br />Evan: 'otherness' is good, but for me it might also mean just another culture; it does not seem as far-ranging as I would prefer. You are quite right about expanding the visual spectrum as a solution. In fact, in the first drat of the post I had written that a pure near-infrared vision would probably result, through mutation and selection, of receptors becoming sensitive to 'new' wave lengths, in this case those of visible light. <br /> Your question about heat spots is interesting. I do not know whether their presence automatically points to endothermy. I like the idea of an ectothermal animals developing specific heat-producing organs instead of heat production being produced just about everywhere in its body as in our kind of endotherms. Such organs could be turned on and off if necessary. I would not put them on the outside of the organism though, but on the inside, with the ability to shunt arterial blood through them in an additional circulatory loop, so the 'hot blood' could transport heat through the body. Did you take the concept that far already? If not, let's patent it... <br /> And I do not think the inevitability of eyes has been proven yet in his post. At present I would say that heat detection ought to lead to an eye, but that is not the whole story yet.<br /><br />Evan 2: well, various animals on Earth already have eyes specialised for different functions (spiders), and in part to different wavelengths (stomatopods), so I personally see no problem there. <br /><br />Ronan: you are right in saying that the visual media of an eye should be adapted to the wave length it is supposed to work with: thermographic eyes should not absorb heat radiation. Crystalline lenses might be needed, as you say. <br /><br /><br />Mithril / Ronan / Spugpow: I like the idea of Fresnel lenses; this is ingenious, and it would work to keep lens volume down. However, remember that they only reduce lens volume, and still project light on a retina at a distance like a regular lens. So they would not reduce overall eye volume that much, and I doubt that lens volume is a big factor compared to eye volume as a whole. Still...<br /><br />Trex 841: The 'visible' part of the visible spectrum indeed differs between animals, but I do not think this means you can say that the entire electromagnetic spectrum could be designated as the 'visible' spectrum. People indeed refer to the part humans can se as such, but while writing the post I thought about what constitutes vision and an 'eye', and through that 'optics'. I guess (haven't thought it through yet) that the rays in question should pass some substances (like air and water) but not all (otherwise there can be no retina) and that they should allow focusing, either by being bent or by being reflected in another direction. Others have probably already thought of such definitions. I'll look them up. <br /> You are probably referring to the 'future predator' of 'Primeval'; wasn't that a bat-derived form? I doubt that echolocation can stand in for sight, but have indeed thought that I should perhaps discuss it at some point.Sigmund Nastrazzurrohttps://www.blogger.com/profile/16449461215427527447noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-72270686356283016102012-01-23T21:30:58.302+01:002012-01-23T21:30:58.302+01:00i've had the idea of the visual spectrum being...i've had the idea of the visual spectrum being a relative term, because some creatures can see light we can't, and this seems to add feul to the fire. what do you think?<br /><br />also, i have a feeling we'll be seeing an old...primeval, friend...trex841noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-38036786010823019192012-01-23T10:17:38.706+01:002012-01-23T10:17:38.706+01:00Excellent piece, Sigmund.
"It's a little...Excellent piece, Sigmund.<br /><br />"It's a little difficult to imagine why exactly an organism would evolve [fresnel lenses]"<br /><br />Maybe a flat organism, like a planarian or flounder?<br /><br />" Something like the trilobites' calcite eyes would probably work best"<br /><br />http://www.newport.com/Infrared-Lenses/381068/1033/info.aspxSpugpowhttp://amnioticoef.deviantart.com/noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-2856129409028755682012-01-23T08:12:07.894+01:002012-01-23T08:12:07.894+01:00@Evan Black
i don't see why an alien creature ...@Evan Black<br />i don't see why an alien creature couldn't evolve such a thing. from what i understand, the compound eyes of stomatopods are similalry adapted, with several 'bands' of eyes in each, each band specialized in seeing a different set of wavelengths and polarizations. apparently this eye structure also gives each eye seperate trinocular focus too..<br /><br />the main question becomes whether the alien eyes in question evolved at the same time and then specialized (which would limit your wavelength options), or one set developed first and later the other more specialized eyes developed.<br /><br />@Ronan<br />i could see fresnel lenses evolving from transparent scales. how pluasible it is who knows though.<br />another possible approach might be the pinhole camera.. http://en.wikipedia.org/wiki/Pinhole_camera<br />an animal with a solid shell having such 'eyes' might not even have visable sight organs, but still be able to see.mithrilhttps://www.blogger.com/profile/03088999203605302318noreply@blogger.comtag:blogger.com,1999:blog-5821098719340852065.post-50694352663202635072012-01-23T07:16:09.322+01:002012-01-23T07:16:09.322+01:00Considering how well water absorbs infrared light,...Considering how well water absorbs infrared light, IR eyes might still be very alien compared to visible-light eyes; whatever the lenses were made out of, unless they were quite small I would imagine that they'd need to be dry. Something like the trilobites' calcite eyes would probably work best, and calcite might even end up as the material of choice, considering its decent IR transmittance.<br /><br />On the subject of eyes that <i>appear</i> alien...how about fresnel lenses to focus light, rather than normal lenses? It's a little difficult to imagine why exactly an organism would evolve them, as the main reason that we humans put up with the reduced image quality is so that the mass or volume of the lens can be decreased--and in animals, eyes typically aren't bulky enough for that to be a problem. Hm. Maybe for a creature that had few predators, but was still under evolutionary pressure to increase its physical size (dermal oxygen exchange in anoxic-yet-well-lit waters? Seems like an unlikely scenario).Ronannoreply@blogger.com