The ‘prancing grec’, a secondarily flightless Quadripterate (Tabulae Mortuae VII, Archives XVII)

 I know, I know; a post on this blog was long overdue. But there are mitigating circumstances. About a year ago I started painting completely different subject material in a completely different style. The style in question is the ‘ligne claire’ (‘clear line’), which is the style made popular by the Tintin ‘bandes dessinées’ (comic strips). The subject material in question is the old city centre of Leiden, where I live. Somewhat to my surprise, people liked them so much that I had two small back-to-back expositions. Preparing for an exposition turned out to take time, so I couldn’t also work on The Book or on the blog, or at least not as much as either deserves.

I hasten to add that I did work on the long-postponed blog about animal feet (working title: ‘What are feet for?’). But that isn’t ready yet, so here is a post about one of those old oil paintings that will not make it to The Book. In this case that is not because I no longer like the painting, but because the anatomy of the animals needs such a thorough make-over that it will be easier to start anew.

Click to enlarge; copyright Gert van Dijk

What you see are two animals going through a mating ritual, involving some synchronised stepping (by the way, I never understood why that is called ‘goose-stepping’; geese don’t walk that way, I think). The animals walk bipedally but are of obvious hexapodal stock. The first two pairs of limbs have evolved into wings, which makes the animal ‘quadripterates’. Their silly small wings definitely cannot lift them, so they are secondarily flightless. While their ancestors slowly adapted to a full terrestrial mode of life, there was apparently no new purpose for the wings, so the wings slowly become smaller. You can imagine successive generations, at first impressing one another with their large wings and implied aerial prowess, while later generations kept flapping their ever smaller and ever sillier wings ever faster.

You can tell that these animals are from a very early stage in the Furaha project (meaning the 1980s). Their scientific name is Penancephalon perplexus, suggesting they are not the brightest of beasts. Their single pair of eyes is on stalks, and the animals may well have a single an unpaired vertebral column or analogue rather than a typical ‘scalate’ anatomy. The hind legs are completely mammalian, with an upper leg, lower leg and extended foot all bending in the expected directions. The toes point forwards, which is something I will get back to in the ‘What are feet for?’ post. One question to be answered there is whether toes must always point forward in running terrestrial animals or whether you can also have backwards-pointing toes. We’ll see.

Meanwhile, the animals are going through their choreographed little mating dance. They look back at the viewer as if to say ’Who are you calling ridiculous?’.                 

Prober and bobbuck II

Recently, I asked readers which colour scheme they preferred regarding the reworked Prober and Bobbuck (P&B) painting, giving them three choices. The one I chose in the end was the ‘African dawn scheme’, with strong yellow and orange as the main colours. If you see such colours in photographs from Africa, you can be almost certain that the photograph was taken at dusk or dawn against the light. There is always dust in the air in a dry climate, and if you look against the sun, that dust provides the yellow-orange glow. The P&B image tries to catch that feeling, and this is also why the sun is low and we are looking into the light.

Click to enlarge; copyright Gert van Dijk

Anyway, I kept part of the prober’s colours bluish, if only to provide some contrast to the otherwise overly monochromic painting. I read a few recent papers about camouflage patterns to see whether there were new developments (here is a recent textual review without figures as examples). The major theme of that review was that many mechanisms can be combined. The P&B painting shows several mechanisms: background blending, countershading, disruptive colouration and probably a bit of motion dazzle.

Background blending is just what the words suggest, meaning an animal has colours and patterns that make it inconspicuous against the background. Countershading is simply having the underside of the body colour lighter than the top. As the belly of an animal will be shaded by the body, shade makes the light belly colour seem darker, and if all goes well, the result is that the belly is just as dark as the top of the animal. This helps with background blending and makes the animal lose its three-dimensional appearance. Disruptive colouration  means an animal has patches of colour that make the overall shape of the animal more difficult to discern. This works best when the colours of the various patches also appear in the background. Many of these effects work best when an animal is motionless, but apparently some also work when an animal is in motion. In fact, ‘motion dazzle’ describes the effect that the motion of patterned objects is more difficult to judge than that of bland, unpatterned objects.  (tis is not the same as motion camouflage).  

Click to enlarge; copyright Gert van Dijk

 

Back to Furaha and to the P&B painting. The prober and the bobbuck both show multiple camouflage features. Countershading should be obvious in both. Without thinking much about it, I made the belies of both animal an even light colour, whereas I could simply have continued the patterns on the rest of the animal but in lighter colours. Apparently, this occurs in Earth biology a lot too (from where I had unconsciously picked it up). The bobbuck’s horizontal stripes mimick the low hills and patches of low vegetation in the plains where it lives and may also help provide motion dazzle. The stripes are broken, both to break up the outlines of the legs and to increase the resemblance with natural features. The prober has a combination of stripes and spots that again help to break up its outlines. You may note that the stripes are largely at right angles to the animal’s contours. By the way, when stalking and in its initial attack run, the prober holds its ‘raptorial appendages’ (its graspers) back and down, closer to the centre of gravity. Its bright undersides are then not visible from the front. Probers only bring the graspers forwards to the attack position when the hunt is on, when camouflage is no longer an issue.    

Does it all work? You may have noticed that I changed the header of the blog to reflect the updated P&B. Somewhat to my surprise, the shape of the animals is not immediately obvious on such a small picture. That may be because of their fairly unearthly shapes, motion blurring and camouflage. I like it myself, but perhaps I overdid it.          

Was there anything else? Let’s see… Oh yes, both animals of course show features of the Great Hexapod Revolution (here and here), with their kinked distal and proximal necks. You may also note that the functions of the vertical (upper and lower ) jaws are separate from those of the horizontal (left and right) jaws. You will not find advanced hexapods in whom all four legs come together to catch prey; doing so poses overly complex demands on how teeth should work together, so the lateral jaws evolved into food gathering aids. If you look closely, you can see that the prober’s oesophagus runs alongside the proximal and distal necks, and not underneath the joints. You may have to wait for The Book to see that level of detail though.

Speaking of The Book, there is progress. Amazon’s self-publishing scheme makes it difficult to predict colours and shades on the printed page. The only way to get a useful result seems to be to change the colours beforehand, in expectation of then the printers will do with them. Or to them. As this takes trial and error using proofs, I am now at the fourth round of adapting colours, saturation, and brightness, among other things. On screen the results now look garish and cheap, but the proofs are slowly approaching how I wish them to look.       

Furaha at Erasmuscon 2024 next August

A month from now the yearly European science fiction conference called ‘Eurocon’ will open its doors in Rotterdam, the Netherlands. Each yearly version has its own name, and this one is called ‘Erasmuscon’. Seeing that Rotterdam isn’t far from where I live, I contacted the organisers about a year ago, hoping they might be interested in adding a bit of speculative biology to the conference. After all, speculative biology went down very well at a similar science fiction convention in London (see here and here).

The result is that I am now scheduled to give a 45-minute talk on Furaha. For those interested, the programme can be found on the Erasmuscon site; I will speak right after the opening ceremony on 16 August, 2024.

The organisers asked participants to come up with a video to use in social media. I wish they had asked that a year ago, so I could have had more time, but I managed to cobble something together. I will present it here, and there is a larger version on YouTube as well.

I decided to do a micro-documentary. The organisers had asked for a short clip lasting 30 to 60 seconds, so I aimed for one minute. The end result is a minute and a half though. I decided that the paintings and a few animations should take centre stage, but just showing an unmoving painting seemed boring, so I decided to play with making paintings move.

To do that, I cut up two paintings in layers representing distance from the viewer. The farthest layer showed the sky and an empty landscape. The next layer represented a part of the landscaper closer by, and in that layer all the really far parts had been removed, leaving a transparent emptiness. The next layers contained progressively closer objects. I wrote a quick Matlab programme to put the layers on top of one another again, with layers shifting more to the right the closer the layer is to the viewer. Repeat that to make as many frames as you want, take a snapshot each time, assemble them into a video and you get a view as if the camera is moving through a 3D view. Anyway, that was the idea, and I will leave it to you to judge whether it worked. For other scenes, the ‘camera’ just moved over the painting, zooming in or out as desired.             

I wished to add a voice comment. I had once played with a microphone which was not a success at all: I had to repeat each phrase many times because I made errors, and the few times I didn’t, an airplane flew over or some other noise intruded. This time, I looked at voice generation and decided to use that. You type in a sentence and hear an AI voice speaking those words. It’s amazing this works, given the general lack of correspondence between the sounds of English words and the way they are spelled. Obviously, the AI behaves like humans in this respect: it ‘knows’ what English words sound like irrespective of their spelling. A funny thing is that the AI did not manage to say the word ‘Furaha’ the way a human would pronounce it. Writing it like ‘Fooh raha’ worked a lot better.

So here is the video; I do not know whether the Erasmuscon people will actually use it in their communications, as I just handed it in. Perhaps I will see you in Rotterdam next month!

Reworking 'Prober and Bobbuck'

The image on the header of this blog still shows an old oil painting depicting a bobbuck being chased by a centauroid carnivore, a prober. Back in 2012 I already mentioned that I was working on a new digital version, one finished at the time. I never replaced the image in the header, thinking that I ought to save all new paintings for The Book. I take that restriction less seriously know and am working on a new 'Prober and Bobbuck' version to account for all the anatomical conversions of the Great Hexapod Revolution. That new one will therefore make the previous one obsolete, even though it was never published. that is a sad fate for any painting, so here it is, at last.

 

Click to enlarge; copyight Gert van Dijk

The original oil painting as well as the now defunct digital one, above, were meant to evoke the atmosphere of a scene from an African wildlife documentary. You will just have to image the voice of the inestimable David Attenborough, providing a running commentary.

But how how far should I take the 'Africa scene' association? Please help me decide.

Click to enlarge; copyright Gert van Dijk

Here is version One. The painting is at an early stage, without any details, and there is also no leg blurring yet (I will first paint the animals and then cautiously apply blurring effects). The light will come from the top left with the sun low in the sky so there will be brightly lit bands while most of the visible parts of the animals show the shade side; those bright bands have already been indicated. The animals are further apart than in the original, not because that improves the lay-out, but to cater for the fold between pages (the 'gutter') when the image is printed as a book). 

The colour of the plain indicates dry grass, at least to an Earth observer. Almost automatically, we assume that the scene represents a hot and dry environment. But for all we know, orange colour indicates freshly sprouted plants in this particular Furahan biotope... 

I played with camouflage patterns taking inspiration from various Earth animals, so there are stripes tending to run at right angles to outlines and large blotches that make contour recognition more difficult (implying that the animals for whom these patterns are meant have visual circuitry relying on colour, contrast and contour extraction much like our visual system). There is also countershading, in which the underside of animals is lighter than their top, so any added shade on the underside will be counteracted. The animal's colour schemes match the surroundings. Nice, but very Earth-like. Too Earth-like?

Click to enlarge; copyright Gert van Dijk

In this second version the colours of the animals do not match the surroundings well, which can be explained, if need be, in a variety of ways: perhaps the animals have strayed into a biotope where their camouflage does not work; perhaps the plants have changed with the seasons but the animals have not; or perhaps the animals cannot see this colour, or cannot discriminate between yellow-ochre and greenish blue. The animals are less Earth-like with these colours.

Click to enlarge; copyright Gert van Dijk

This third version has blue-green vegetation, which is not strange on Furaha. After all, large plants on Furaha consist of three groups with differently coloured photosynthetic pigments. The result is that the animals and plants match one another, albeit in a way not found on Earth (not at present anyway; dinosaurs may have sported colours that mammals cannot produce). An interesting aspect is how strong our preconceptions about what colours mean are. Will people interpret the lighting with a low-set sun, or will they assume a nighttime scene because of the bluish colours? I could turn the brightly lit bands yellow in an attempt to counter that (unless that evokes moonlight!).   

I must decide before I start finishing the painting; which one do you prefer? One, Two or Three? If possible, can you say why?

Could plants be shaped 'webbed' instead of 'branched' ? (Alien Plants VIII, Tabulae mortuae VI, Archives XVI)

 There are at least three clades of plants with different photosynthetic pigments on Furaha. While having leaves that are not green creates some 'otherworldliness', the shape of these plants is the one we know well: a stem with branches and leaves. At one time, some Furahan plants had enormous sail-like leaves. Unfortunately, reading about wind stresses on plants made me realise why Earth plants do not have sails or giant parasols for leaves. They are poor engineering, as giant leaves would suffer from wind damage (see here for what it takes to get large leaves). With some regret on my part, giant leaves followed ballonts (see here) on their way to the Forbidden Vault.

Even so, I always felt I should do more with plants and will share some ideas here. I find mangrove forests fascinating: plants, standing in salt seawater, form a barrier against waves and create their own ecosystem. Why are they limited to some tropical coats, and why aren't temperate coasts also blanketed with a whole range of different 'mangrovian' ecosystems? If Earth doesn't offer us such a spectacle, could Furaha have vast ribbon-like forests covering its coastlines? That's something I haven't worked out yet; I should probably first understand why this does not happen on Earth. So far, I suspect that the origin of Earth's land plants, stemming from freshwater organisms, has something to do with it, which begs the question how mangroves manage salt water. I will have to study that, but for this post I am more interested in how they withstand waves.                          

Click to enlarge; copyright Gert van Dijk

Click to enlarge; copyright Gert van Dijk

Another plant aspect I once came up with was a desert ecosystem in which the local plants really went out of their way to fend off herbivores. Some plants produced caltrops, also known as crow's foot, among other names. Caltrops are the unpleasant pointy bits of iron strewn on the ground to make life difficult for the enemy's men and horses. In the case of Furahan caltrop plants, the spikes grew upward from the roots of some trees and shrubs.

Click to enlarge; from Wikipedia

Those Furahan root spikes looked -intentionally- like the top left caltrop in the image above, dating from 1505.

Other shrubs had nasty strong and very sharp thorns. Still, some herbivores, like the animal shown lying in the shade in the picture above, developed a string and tough carapax allowing them to move through the nasty shrubbery. The image is from an old oil painting that I later decided did not work  well, so it was delegated to the Forgotten Attic.        

But one plant species isn't on the painting. What if thorns that constantly touched a branch of the same plant would bend around that branch, clasping it firmly? If that would happen on many branches, the result would be a strong structure, one in which branches could not simply be pushed aside. This weblike structure would make life more difficult for herbivores, putting most of the plant outside their reach (well, until they evolved long tongues or the equivalent of pruning shears, of course).   

Click to enlarge; from Wikipedia

       
Another way to reach this webbed structure involves 'inosculation'. That isn't a concept I came up with for fun, but an existing word: here is the Wikipedia page on inosculation. According to Wikipedia, when tree trunks or roots rub against one another, the bark may wear off and the cambium, the live growing tissue of a tree, of the two touching parts may fuse and grow on from there, ultimately producing new bark around the touching area. This explanation centres on damage to the bark exposing the cambium. Grafting, the artificial variant of inosculation, also relies on would healing.    

Tree roots can certainly fuse, but roots do not move much, so I find it hard to believe that root inosculation must start with damage due to rubbing. This suggests that mere touch or pressure without movement seems sufficient to start inosculation. But roots and trunks can also press against stone, and such pressure does not seem to abrade the bark at all. In the end, it is often the stone that moves instead! Do trees recognise that they are touched by another part of themselves, and then allow or even favour inosculation? I found some evidence that some plants, like English ivy and strangler figs, readily from natural stem grafts (in this free paper). You can imagine that a climbing plant might benefit from a web structure. 

Click to enlarge; from Wikipedia

 

A strangler fig needs to be able to stand on its own stems when its victim dies, and firm connections between the stems are then quite beneficial. The image above, from the Wikipedia page on strangler figs, shows this fusion tendency quite clearly (but the page does not mention this).

That paper led to another stating that roots indeed graft naturally (here). One explanation for this tendency was that connected roots provide better anchorage (for other explanations, read the paper).

Well, well. It seems that some Earth plants indeed readily 'inosculate' to obtain a mechanical advantage! That is what I wanted, and as usual every time you think you had an original idea for a Speculative Biology project has already been tried by 'Nonspeculative Biology'...

All this makes me think that Furahan plants could do with more self-inosculation. The resulting cross-struts offer mechanical advantages that might help Furahan mangrovian plants to withstand the force of waves. In deserts, I can see plants preventing access to herbivores too.

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For other posts on alien plants, start here or just search the blog for 'alien plants'. And for other posts of defunct paintings, start here. 

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This is post #300! I also forgot to mention that the blog passed its 16th birthday in April, and that the 300 posts amassed a total of about 2680 comments. 

Some modest website maintenance

 I haven't changed the main Furaha website in quite some time. The odd thing about old sites is that sometimes animations stop working or images become invisible, even though they did work initially, and nothing changed.

I was asked by someone, who wanted to know more about animal locomotion, about some of these animations. I decided that some attention was long overdue and started work on it. I found that in some cases the case of one letter differed in the html file and the actual file name, so it seemed that html has become less forgiving. I also added -slightly- more modern html code to make the animation work better.

I then recalled that someone else had asked whether the old 'Furaha right now' page would ever be reinstated. That page showed pictures of the planet around its sun Jua and of the distribution of light and dark on the planetary surface, updater roughly every Earth hour. At one point I had to remove that page because at the time I could not store all 900 images for one year on the server, and so had to remember refreshing them every month or so. I have more room now, so I polished the output a bit, ran the Matlab programs again, transferred the 900 images and made a new menu item: 'Furaha right now'.

Click to enlarge; copyright Gert van Dijk

 Here is an example image showing a map with day and night areas, as well as two globes representing the dayside and the nightside of the planet, at one particular time of day and particular point in the planet's orbit.

If you revisit the page often enough, you may find out how humans on the planet devised a calendar to cope with their 551.1 day long year.

However, nothing else has been changed, because I do not have the time: I am working on The Book and a different art project altogether. But I will get to it. At one point.  

A psychotherapist space spider

The recent Netflix film 'Spaceman' is an adaptation of the book Spaceman of Bohemia, written by the Czech/American author Jaroslav Kalfař. It is about a lone Czech astronaut travelling a long distance in the solar system to investigate a strange space cloud. A major theme of Spaceman is the loneliness of the astronaut. If you like philosophical themes and are not in a hurry, Spaceman is well worth watching; however, those who prefer ray guns and explosions might like it less.

But this blog is about speculative biology of the extraterrestrial kind, not about film reviews. While the astronaut, Jakub Procházka, is lonely and far away from other people, he is not alone. I am not talking about the ship's cat here, not that seems to be one. An alien being that is best described as a spider the size of a small child shows up aboard. How is unclear and you will probably wonder whether the spider is real or whether we see a hallucination springing from Jakub's too lonely mind. The internet seems full of discussions of that particular topic, so I will not discuss this. Well, in fact, you do see a small spider moving under Jakub's skin in the beginning of the film, which seemed to me a strong hint that the spider originated inside Jakub, not as a physical being, but as a concept.    

Anyway, the nice thing is that we get to see the space spider in sufficient detail to analyse it as a speculative biology entity. 

Why is it called a spider? You wouldn't expect alien beings to conform to Earth cladistics, after all. But there are certainly similarities. It has eight legs with long slender elements sticking out sideways. There is a big bulging abdomen, as well as a head. If it would be a proper Earth spider, that head should be fused with the trunk to form a cephalothorax, but this space spider head seems movable relative to the trunk part. The head has six eyes, not eight, even if some reviews mention eight. 

Click to enlarge. Nentwig et al. All you need to know about spiders. Springer 2022 

 

Click to enlarge. Nentwig et al. All you need to know about spiders. Springer 2022 

The eyes of Earth spiders are quite interesting and variable between families of spiders. There are not always eight, in fact, and six is definitely possible with Earth spiders. The two images above show that clearly. The eyes of our space spider, christened Zanuš by Jakub, appear to have pupils. The eyes seem immobile, and they are enclosed by a ring of elastic tissue, allowing them to become larger and smaller in apparent diameter. That is a clever trick that helps convey emotions. There are two large eyes and four smaller ones, but otherwise they all look the same. On Earth, different  eyes have different functions, and that shows up in their size, colour as well as the apparent direction they seem to be aimed in. We will get back to that later.

There are two very large cheliceres pointing straight down from underneath the head. I haven't seen Zanuš using these fangs and do not know what they are for. Then again, what can fangs be for? It does make you wonder what these space spiders do in their natural environment.

There are additional limbs around the mouth, and in one touching scene, shown above, Zanuš accepts a spoon from the astronaut with some food on it. These mouth limbs can then be seen to be tentacles, and tentacles are definitely not in the anatomical repertoire of Earth spiders.

There is one more big departure from the Bauplan of Earth spiders: Zanuš is obviously endoskeletal, as can be seen from the clip. There are tendons connected to bones, and the entirety of the body is covered by hairy skin. This is certainly not an exoskeletal joint with hinges open to the outside world. The joints are, like vertebrate joints, well and truly inside the leg. The legs, by the way, end in two prehensile fingers each. Zanuš clambers around the inside of the spaceship grasping objects with these tiny hands.

So what does all this suggest? A first explanation is that, if Zanuš is a figment of Jakub's imagination, Jakub knows very little about spiders. I doubt that real astronauts get much zoological training, so that is fine. A second option holds that Zanuš is a real being; inside the story, of course. If so, his Bauplan is interesting, and we will get to that. The third level is the one the creature designer and film makers used: why did they choose this design? 

Let's play along and see what we can make out. We have an endoskeletal animal the mass of a small child, with lots of fairly thin legs sticking out sideways. The legs, fur and locomotion all suggest a terrestrial origin; this is not a swimming animal. The legs are very spindly and stick out sideways; that, plus the presence of tentacles, suggests a world with very low gravity. The ability to grasp objects all around further suggests that the creature would be at home in a 3D environment, such as tree branches. 

Click to enlarge. Nentwig et al. All you need to know about spiders. Springer 2022 

One thing bothers me in all this: Zanuš' eyes all look in the same direction. In a 3D environment, it pays to be able to look in most directions at all times. If your Bauplan has multiple eyes, it makes sense to move some to achieve all-around vision. Spider eyes follow that principle, at least for some families, as shown above. In contrast, if your Bauplan only provides two eyes, which is a poor choice if you ask me, then evolution can be expected to place them where they do best. Here, they would be seeing what you eat and also covering as much of the world as possible. Not surprisingly,  the eyes of many fishes and birds that do live in a 3D environment are placed at just the right spot to achieve such goals. Of course, many birds and mammals have eyes that  depart from that pattern. If you only have two eyes, stereoscopic vision can apparently outweigh the need for wraparound vision. With multiple eyes, you can easily get it all, but Zanuš' eyes all look ahead. That seems odd.

In the story, Zanuš proves to be a thoughtful and respectful psychotherapist. You need good eyes to pick up tiny nuances in expression, posture and movements that tell you a great deal about someone's state of mind, but not eight ones!

A final word in this rather meandering post. I cannot speak for the general audience, but I quickly liked Zanuš, perhaps because I am not really afraid of bugs and small arthropods. I rather like it that the film makers dared choose a shape that many people find repulsive. I do not know whether many people actually turned the film off, disgusted by Zanuš' spider shape. I hope not, because the world could do with a bunch of sympathetic Czech/alien psychotherapist space spiders. Then again, I still wonder what Zanuš' people use those enormous fangs for on their home world...