Tuesday, 26 July 2016

What do Roman soldiers, trilobites and the Furahan Droodle have in common?


Click to enlarge; copyright Gert van Dijk
Before answering that, you are probably wondering what a Furahan 'droodle' is. Well, one description found in the 'Annals of IFB Field Expeditions' reads as follows: 'The droodle is a slow an silly creature, behaving in its snug little world like the Lord of Creation, notwithstanding its utter insignificance'. Apparently the Annals did not require any semblance of scientific impartiality before accepting contributions, but that is not the point. Further on the author continues: "It can behave this way because it is well protected because of its foul taste and because of the overlapping armoured plates covering nearly its entire body."

An early version of the droodle is shown above. And there we are: the droodle has an armour consisting of overlapping plates, and so did trilobites, and so did Roman soldiers. I came across the subject when I was preparing to paint the droodle anew for The Book. Most of my new paintings have very little to do with the old ones, but I like some old designs enough to go over them again, taking the opportunity to improve them in as many ways as I can. I started wondering how animals manage to move while covered with what seem like very stiff plates. How are these plates attached to one another? Obviously, in arthropod legs the exoskeleton of adjacent parts of the leg form joints that often have just one axis of movement, much like our own knees: we can bend it stretch a knee but it does not move sideways nor can we rotate the leg and foot backwards. I started thinking about whether that also applies to the plates covering the droodle.

Click to enlarge; copyright Gert van Dijk



Above you see the result of simple experiment: I wanted to form successive hoops curving around the animal's back while widening at the sides. I imagined a hinge between two hoops with the axis of rotation about halfway up the animal. Of course, such an axis of rotation would make sideways movement impossible, but so be it. I assumed that the plate in front would slide over the plate in back. I could imagine that in my mind's eye for half-circular hoops, but felt I needed some visual help with hoops that widened at the side: could they in fact slide over one another over their entire length, or would they intersect, making the movement impossible? So I made a rough shape like that in Vue, of which the top surface represents the plate. As you can see, at the centre one hoop can easily slide under the next one while it wants to move over it at the sides. This does depend on the site of the hinge and some other aspects, but it does show that you cannot assume any angle or shape to work. I could of course still paint it the intended way and no-one would be the wiser. But science has preference over art in such matters. So what was wrong?
 
Click to enlarge; Manton, The Arthropods 1977
I then thought of trilobites: their name indicates that their bodies had three lobes lengthwise, with a thick part in the middle and much narrower side flanges, much like the droodle. And trilobites could roll up their bodies, so they solved the problem how to slide one hoop under the other better than I had (weel, they had more time...). I obviously needed expert guidance, perhaps a book called 'Biomechanics of trilobite intertergite movement' (the hoops are called 'tergites', just so you know). I found something close: 'The Arthropoda' by S.M. Manton, 1977. I am not new to reading scientific papers, but this book is as intricate as it is condensed: the reader is assumed to be rather well-versed in arthropod classification and anatomy. The book contains sentences like 'There were no coxal endites or gnathobases.', in its own way as wonderful as 'It was a dark and stormy night'.

Click to enlarge; Manton, The Arthropods 1977
So here is Figures 1.5 from that book: have a good look at the top right in particular: the tergites are connected by a fold of skin, doubling back on itself. There is no hinge to be seen anywhere. If the tergites are indeed connected only by such a fold over their entire length, they would have much greater freedom of movement than if there were just one axis of rotation: this is a good idea.

I then wondered if his is how all armour segments are connected in arthopods, and browsed through the book. As you would expect, there are a myriad adaptations of tergite movement. In species that burrow, successive tergites are kept from sliding over one another and have a built in 'door stop', allowing the animal to push the soil out of its way. In other species there are additional small tergites normally hidden between larger ones. When the body is flexed, the gap that would otherwise appear between the large ones is filled by the small ones. In many cases tergites only cover the back of the beast. There may be other bits of hoops at the belly (sternites) or the sides (pleurites), all of which are connected to one another by the folds of skin.

Click to enlarge; from The Arthopods, SM Manton 1977
Here is an example of the intricacy of the internal anatomy of a millipede. The large top image shows the poor millipede cut lengthwise with its body flexed (the back is at the top). The lower left image is a horizontal section of the body rotated sideways. Complex, aren't they? The feature I would like to call your attention to is the folding of the skin between tergites: I found that in all such plates.

So I learned from all this that arthropod tergites can in fact be connected by 'hard points', but in many cases the skin folds allow flexibility and freedom of movement. So that was one problem solved, but all this did not answer the question how to ensure that the tergites do not 'intersect' while rotating, as they did in my simple model? Or how do you avoid having large gaps form when the animal moves? There may be several answers to these questions. Perhaps the tergites should be flexible.


video

( video does not seem to work; I will check later...)
Have a look at the YouTube video above, of a millipede flexing its body in all directions: the tergites do not show any gaps at all, and yet they slide over one another in at least two directions of rotation: they must be flexible. But would that work for a big animal, in which you would expect the tergites to be stiff? (but never brittle: the armour must be capable of withstanding blows, and allowing it to deform it a bit should absorb the energy of a blow). 

Another solution would be to forgo tergites that run from one side of the animal to the other; split them up in separate parts instead. These smaller plates could each be tough, and be connected with skin folds. At the top of this post you'll find a simple model I made to see what a droodle designed in this manner might look like. Mind you, this is not what the painting look like: the droodle has already evolved some more and no longer looks like this, but it does still have multiple overlapping tergites.

Click to enlarge; source here
So what about the Romans? Everyone who has ever seen a film with Roman soldiers in it, or who has read an Asterix book, knows that their armour consisted of metal hoops circling the soldier's body. This seemed very similar to the tergites of trilobites or other artropods, so I wondered how the legionnaire's hoops were connected, That was easy to find out: there are books describing actual archeological finds. The image above is from tha reconstruction based on such finds. The Latin word for this particular type of armour is 'lorica segmentata' ( I also leaned that all these films might be wrong: this plate armour type may not have been the standard type of armour; chain mail may well have been more common.) And here is how the loops are connected: not by hinges, but by leather straps on the inside of the hoops.

video
( video does not seem to work; I will check later...) 
The video above shows the Roman lorica in action (the inside is well visible two minutes into the video). The hoops could slide and rotate a bit with this arrangement, in exactly the same way that the tergites of trilobite could slide over one another thanks to being connected by folds of skin. Only the trilobites had their armour some 520 millions of years before the Romans invented their lorica.

So this is how the droodle came by its armour and by its scientific name of 'Lorica segmentata'. There is a long list of items the Romans did for us, to which I would humbly like to add that they can make you think how exoskeletons work. Not a bad thing at all. 

Saturday, 11 June 2016

The anatomy of giants in 'Game of Thrones': did they get it right?

Every now and then a giant shows up in the television series Game of Thrones. Obviously, GoT is not a nature documentary so there is no reason to be difficult and analyse it scientifically. After all, it has dragons that cannot fly but do. But as their eggs only hatch after having roasted in a funeral pyre there is magic involved, and that should do the trick. Still, every time a giant ambles across the screen, the science routines in my mind spring into action and start wondering about its anatomy.

Click to enlarge
The giants do not just look tall but broad as well, and that makes sense. Their legs seem extremely broad and columnar, as wide as the feet. The feet do not even stick out much in front, unlike ours. The outer shape of the clothing suggests that the giant has feet like an elephant, with toes and a big elastic pad in the sole, all encased in a cylinder. But all those rags and furs hide the giant's shape so it is hard to tell. Perhaps the actor is standing on high heels or stilts to add some height, and the wide trouser legs are meant to hide that. The leg/foot assembly does look rather long.

So every time I see a giant I think: 'That looks convincing; I wonder whether they asked some biologist how to make a giant'. And then of course my attention is diverted away from that by someone being murdered unexpectedly in a gruesome manner; it's GoT, after all. In this series people die all the time, and with some recent story developments they might even do so more than once. Recently (series 6, episode 7) a giant stood still in one shot, together with some puny humans. His name is apparently 'Wun Weg Wun Dar Wun', in case you wonder, or 'Wun Wun' for short. I thought I should get that frame to have a closer look, after the killing would be over (temporarily, that is).

Click to enlarge
So here is the shot in question. The giant appears twice as tall as the man on the left, who I suppose is normal height. I estimated that man's height to be 1.8 meters, so the giant would be 3.6 m. tall. Some internet searching revealed that the actor playing Wun Wun is over 2.1 m tall. What the producers  did was to use low camera angles to simulate his size. Here is a video of that, but be warned: Wun Wun is visible for only a few seconds.

Click to enlarge
I copied the giant, and reduced his size to what should be about 2.1 meter, compared to the 1.8 m man. I stuck him in again to get a feeling of what the actor may have looked like without special effects. Here is the result of that, including doing away with the blue overcast. It does not look as if he is walking on stilts, so the cylindrical shape of his legs is probably there to suggest just that: big legs. He looks very broad; should he? What should the proportions of a 3.6 m tall giant be like?

To find out, please read the first and second post in this blog on why body size matters. In short this is what happens if you double the length, width and height of an object or animal: its mass and hence weight will not become twice the original amount, but eight times as much. But the strength of a bone is given by its cross section, and if you only double the radius of a bone, its cross section becomes four times as large. But the bone needs to be able to support eight times the weight. This means its radius has to increase disproportionally: if the weight increases eight-fold, then the cross section needs to increase by a factor eight too. The radius needs to increase by the square root of eight, which is 2.83 times. In case you are dazzled, it boils down to this: increasing bone length by a factor of 2 means that bone diameter has to increase by a factor 2.8.

Mind you, in real life that is probably not enough ('real life'?; what am I thinking here?). Muscle strength also depends on its cross section, and to keep the same relative strength means muscle cross section has to increase by a factor 2.8 as well, meaning more muscle mass. All these extra increases in bone and muscle will add mass, so the bones have to be even thicker and... You see where this is going. At some point there is no mass left for lungs, guts or brain (judging from Wun Wun's speech patterns, some savings were indeed made in the latter department). Say we use a factor 3.0 to accommodate for all that.

Click to enlarge
Here is a nice schematic human anatomy image found on the internet. I cut it up in sections and increased the width of the sections appropriately. Well, mostly: I reasoned that the increase should certainly apply to the thickness of weight-bearing bones, such as legs and the vertebral column. I did the same for the arms as well, or the result would look silly. But in principle pelvic and thoracic width do not need an additional increase beyond the factor two we started with. I did increase them some more, if only to give thigh muscles some room.

Click to enlarge
Here is the result of this simple attempt. Do not forget that he is twice the size of the man we started with. The resulting giant certainly looks large as well as stocky, and so he should. Note that I increased the feet a bit more, to allow all the thicker foot bones to lie next to one another, as they must. But I did not alter foot anatomy any more. Before we discuss that further, let's approximate the giant a bit more by using the body outline and adding a suggestion of clothing.

Click to enlarge

 
Here it is. This is what a morphologically reasonably sound 640 kg giant might look like.

Click to enlarge
And to get a feeling for size, here is the giant next to a normal-looking human on the left, half the size. The giant is not that different from Wun Wun, confirming my intuitive guess that the designers got it right. The hands look quite good. The actor must have been covered in very thick layers of padding to get the stocky look. It is not often I get to write that the television or film industry got their biomechanics right. Regular readers will know that there was little reason to be happy before; see the posts on Avatar and John Carter of Mars.

Click to enlarge

The one remaining matter is whether the giant should have his feet examined: can he stand on human-type feet or must he have elephantine feet, as shown above? If a 1.8 meter m. tall man weights 80 kg, a 3.6 m. giant will weigh eight times that, so 640 kg. Being bipedal, one leg has to be able to withstand all that weight. Mind you, we already have taken that into account as far as bone strength is concerned. Still, that is a lot. But Wikipedia tells me that draft horses weigh up to 1000 kg and giraffes weigh up to 1930kg, and these animals do not have elephantine feet. While running just one of their legs may be on the ground, with a lot of dynamic forces acting on the bone as well. So I do not think a 640 kg humanoid needs elephantine feet, but that does not mean he cannot have them. All this brings up the topic of whether very large bipedal animals should have elephantine feet with embedded toes, or whether they should have free toes, sticking out. I am in favour of the latter, but that is something for another post, on toes.    

Unless the GoT designers tell us what Wun Wun's feet look like, we will never know.  Unless... unless of course we get to see a naked giant. GoT is not afraid of nudity and there have been calls for nudity to be more equally divided among male and female cast members. Perhaps that equality should include not just sexes but species, too. So let's have a naked giant; purely for scientific reasons, obviously. Actually, just the feet would be enough, thank you so much.      
    

Tuesday, 24 May 2016

Painting a Cthulhuoid carapax (Digitally painting Furahan lifeforms II)

As blog titles go, this one is not likely to win the prize for 'succinct clarity'. Actually it could, provided readers already knew what a Cthulhuoid was, what its carapax was, and why you would want to paint said carapax. To make matters worse, there formally never was a 'Digitally painting Furahan lifeforms I'. But one earlier post would in retrospect deserve that title.

What does the title mean? Well, the word 'Cthulhoid' describes a clade of marine Furahan animals that do not seem to be able to make up their minds whether they should be pelagic of benthic ('pelagic' refers to the 'just water' part of a sea or lake, not close to the bottom nor to a shore, while 'benthic' refers to the bottom of a sea or lake). Some Cthulhuoids use the tentacles close to their face -hence the name- to move around on the bottom or even create their own hiding places, while others use their fins to propel themselves through the sea. A 'carapax' (a term I prefer over 'carapace') is an animal's armour, say its shell. The cthulhuoid carapax covers the head and usually part of the back. Finally, why would you want to paint one? You, the reader, might in fact not want to do this at all, but I wanted to, to create an image for The Book.

I am not going to spoil The Book by showing major paintings here or anywhere else, but I can make an exception for part of a minor illustration. The illustration in question shows a few examples of the riotous array of colours and structures of cthulhuoid carapaces. The problem with 'riotous' colours, in stripes and spots, is that every spot must be painted in the correct shade for where it is on the object, and that includes different shades within each stripe or spot. With oil paints this proved to be a painstaking job, requiring small pointy brushes, a very steady hand and lots of patience. Digital painting has made painting such complicated objects much easier, as I will illustrate here. I will assume some familiarity with 'layers' (in digital painting, a layer is like a sheet of glass: what you paint on it covers things on underlying layers, but parts unpainted on a layer let you see underlying layers. You can paint on a layer under another layer. I use Corel Painter because it can mimic real brushes quite well.


Click to enlarge; copyright Gert van Dijk

Let's start with a suitable carapax shape. I modelled one in Vue Infinite and made a simple render in which the 3D shape is overlaid with simple lines that define contours of the shape. These help get the perspective right, in a fraction of the time that a conventional perspective construction would require.  On a separate layer I drew lines with a 'brown pencil' to outline some interesting spots, aided by the lines that help keep the 3D shape in mind, and also help ensure symmetry.


Click to enlarge; copyright Gert van Dijk


The next stage uses a layer under the brown pencil one. This new layer contains the basic colour of the beast, which in this case means dark blue sides with a lighter colour down the middle. Note that I made absolutely no effort to represent shading here: the colours are supposed to be completely flat.

 
Click to enlarge; copyright Gert van Dijk
I then added another layer, again just under the pencil layer. On that one I painted the spots an even deep yellow colour, to contrast with the blue underpainting. Again, this is completely flat. Note that the result contain three layers: the pencil lines, the yellow spots and the blue basic colour.  We will leave these layers for now and hide them from view.



Click to enlarge; copyright Gert van Dijk

Using the same Vue render as before I then painted the carapax again, but this time without colour, using just shades of grey to convey a sense of depth as well as a surface texture with same plates on it. I rather like the way the shininess turned out: the surface is shiny, but more like a pearl than like chrome. The shininess should allow the colours to remain well visible.


Click to enlarge; copyright Gert van Dijk
The trick now is to combine the flat colours with the grey layer defining the shape. There are at least two ways to do this. In the one shown above, the grey 3D layer changes the aspect of the solid colours below. There are many ways in Corel Painter or in Photoshop of making one layer affect an underlying one. It is often hard to predict what they do as their names often make limited sense. The result shown above was obtained by applying the grey '3D' layer to the underlying flat colours as 'hard light'. Not bad, is it? You may note that part of the 3D structure indicated by the grey layer is obscured by the strong colours. That is very often the case with strongly contrasting patterns.



Click to enlarge; copyright Gert van Dijk

This particular image is based on the opposite approach: the grey 3D layer was used as the underlying basis and the colour layers were moved on top of it, where they affected the grey layer through an option labelled 'colorize'. As you can see the result is not the same, which is part of the fun of digital painting: there are new options to discover daily. Of course, it may be better to stop discovering them and get to work at some point, or you will never get any work done.


Click to enlarge; copyright Gert van Dijk
Finally, I went back to the earlier version and decided to change the colours on the flat colour layers, which only takes an instant. The blue basic colour became solid yellow, and the yellow spots turned black. The grey layer is again used to provide a 3D aspect to the carapax, but this time I turned down the 'hard light' effect so the highlights are less conspicuous. I then added two shiny spots with fairly sharp edges to get a surface effect like porcelain. On yet another layer I painted flat white regions at the edges of the carapax. These were then made almost entirely transparent to represent reflections of lighter objects in the vicinity. I present this version here to show that separating colour and structure allows for some quick experiments. It is not the way I paint most often though: usually I paint shadows directly, using appropriate colours.

To paint other shells I did not use this method, as I thought that using the same outline every time would make the result boring. Instead, I designed and painted a new shell from scratch each time.  

And there you are; a painted cthulhuoid carapax. The illustration should end up as probably about two by two cm, so it will be small. This particular carapax belongs to the species Myrmillo testudiformis, or in common speech the 'turtleback snigel'. Such shells are collector's items, by the way.

Friday, 6 May 2016

Terryl Whitlatch's Creature Design

Click to enlarge; copyright Design Studio Press
 This post is about two fairly new books by Terryl Whitlatch, both with 'creature design' in the title: one is 'Principles of CD', and the other is 'Science of CD'. I have kept an eye on her work since I posted about the wildlife of the Star Wars universe, back in 2011. I expressed my admiration for her technical skills, but had a few reservation on other matters, and wondered whether or not I would feel different this time. When a book on creature design comes out with 'science' in the title, it will definitely get my attention. So, is the title correct and is there science in there? Well, yes. And maybe no.

The 'yes' part of the answer concerns animal anatomy. 'Understanding animal anatomy' is in fact the subtitle of the book. The book does cover the subject, by presenting many animal species three times: one as a drawing of its skeleton, one with muscles attached, and one with skin, hair, flukes, etc. The book is strongest on mammals, although there fish, amphibians and dinosaurs as well. However,  anatomy is presented from the artistic viewpoint only, so do not expect joint design principles,  biomechanics or similar matters: that's not what it's for. The drawings are excellent, as always. There are several extinct mammals in there, that are all very convincing as impressions of what these animals could have looked like. I wish Ms Whitlatch would illustrate a book on extinct mammals: it would be wonderful. 


Click to enlarge; copyright Design Studio Press
Here is an example of her work at its very best. This is a Diplocaulus, an early amphibian with an odd head. What Ms Whitlatch has done is to have the animal float immobile in some pond or lake, completely submerged. In doing so she immediately evokes a newt, which I think shows genius.

Click to enlarge; copyright Design Studio Press
The 'maybe no' part has to do with imagining new animals. In these books, most fall into the fantasy or mythology category, combining bits of one animal with bits of another. That is not something I distilled from the animals, but something stated in the books: the donor animals providing the original parts for the new chimaera are usually named in the book. The results can be fascinating to look at, although my impression was that the result is much more about the effect on the viewer than about creating a viable animal. The dog/fish hybrid shown above is an example: it is funny to look at, but does not make much sense as an animal. 

Click to enlarge; copyright Design Studio Press
I discussed this particular design before, but as it is in the new books as well, I will show it again. It shows the common theme of doubling or tripling front legs if you need an animal with three or more pairs of legs. It is apparently hard for illustrators to come up with something else (see my earlier posts on Barsoom animals or Avatar's hexapods). In common with these forerunners, this animal's legs are placed very close together resulting in little, well, leg room.

Creature design in games and in Hollywood seems to have very little respect for biological plausibility, something I have discussed several times in the blog, with irritation as well as sadness. I used to think that this was simply a sign of the complete indifference Hollywood has towards facts of any nature, regardless of whether the facts have to do with history, astronomy or biology. But over time the discussions by readers in this blog made me change my mind. I expect that there is purpose behind the negation of facts. I expect the people high up, who make such choices, to be fully aware of what their audience prefers, and that is close to what they know already. The artists and experts might wish to go much further, but might be reined in lest as otherwise the audience might be dragged from their comfort zone. Of course, by never challenging the expectations much the whole process becomes self-fulfilling...

Click to enlarge; copyright Design Studio Press
Back to the books; here is a similar design, this time for an animal with seven pairs of legs. I like the smooth progression of the phase of the movement. However, once again we see that the front pair is copied: there are no less than six 'front' legs, leaving just one other design for the hind legs. The legs are again close together and their musculature seems suitable for such an animal with just four legs, rather than fourteen. Perhaps you argue that the creature belongs on a world with high gravity requiring lots of stout legs, but the tail design does not fit with a high gravity (it is a long unsupported structure that would need much force and appropriate skeletal adaptations to keep it horizontal and there aren't any: the spines point downwards, not upwards where you would attach ligaments to keep the tail suspended).

Click to enlarge; copyright Design Studio Press
Finally, here is another one in which mixing animals magically has its disadvantages (I am to blame for the parts of the image being cut off; the book did not fit in my scanner). Its head looks like a ceratopsian's with mammoth tusks attached. Spectacular, yes; but wouldn't the tusks be in the way when the animal tries to reach food with its beak? Actually, the part that drew my attention initially was the elbow joint of the front legs, correctly placed at the height of the underside of the body. That angular form really conveys a big elephantine shape very convincingly.

In conclusion, the books show many excellent drawings. They represent some of the best of this particular school of 'creature design', involving people mixing various Earth animals together. This makes their shapes 'natural', and in turn this makes them instinctively believable. However, for anyone with a trained eye, the mixture also abolishes any notion that the animals might have evolved biologically. It may be just me, but that effect detracts from their believability. I can suspend disbelief as well as the next person and so enjoy these creatures very much; but I generally prefer designs that evoke an evolutionary rather than a mythological background.   

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Will I take up blogging again? Maybe; I will write the occasional post, but still think it is better to devote the time I have for The Book. It is progressing steadily and has sixty pages completely ready (if you ever write a book, do just that and write it; do not paint a book). I will keep you informed every now and then. Here is a titbit: mixomorphs are now haplodiplontic beings in which both stages are complex multicellular lifeforms, albeit different ones...

Saturday, 26 December 2015

The Return of the Common Cloakfish

From time to time I find that my self-imposed restriction on not doing any Furaha work except working on The Book begins to chafe. I know that animations cannot feature in a book, but they are fun if very time consuming, and that holds for blogging too. So I gave myself a short vacation from painting and went back to an old favourite: cloakfish. The type of cloakfish shown in this blog previously as well as in this particular post is by now a primitive one. More evolved cloakfish have shown a considerable adaptive radiation: bodies were squeezed, cloaks either merged with the body or were stretched, etc., etc. There are now 'short sleeved' cloakfish as well as 'long sleeved cloakfish'.  The protocloakfish I will show in this post is a long sleeved one: the cloaks are considerably longer than they are wide.

The novel feature I wished to explore had to do with cloak movement. Until now, the cloaks moved with waves undulating backwards over the fin, pushing the animal forward. If you look closely at squid and cuttlefish, Earth's own indigenous aliens, you can at times observe that there seem to be several waves travelling over their fins at the same time: let's call them major waves and minor ones, and each set seems to be controlled independently. Here is a YouTube video showing squid movement: most of the time you see just one type of wave, but at times the pattern changes. I would not be surprised to learn that fin control in cephalopods is neurologically quite complex. I really must look up what I can find about that in my books on cephalopods (yes, I have more than one book on cephalopods: every self-respecting geek with an interest in speculative biology should devote part of a book shelf to cephalopods).

video


To start with, here is a simple animation showing just one wave pattern; let's call these the major waves. The waves are fairly large, meaning their amplitude is large and so is their length: they take up a sizeable portion of the cloak. The gait of the four cloaks is the 'opposite' pattern, in which the waves of neighbouring cloaks approach one another. The red ball is there only as a reminder where the 0,0,0 point is in this virtual 3D space.

video


The next phase, above, is of course to show the minor waves: there are more of them and they travel faster along the cloak. Mind you, I have not considered the effects of interacting waves on propulsion much yet; my first suspicion is that they can augment one another, but if they can do that, they can probably also hinder one another.  Hm. This will require thought.

video

Anyway, programming and visualising all this makes it difficult to think of everything at once, so first let's see what the combination looks like. Here it is. I like it; it is complex and looks organic and fairly odd. The movement reminds me of that of nudibranchs (if 'nudibranchs' mean nothing to you, just use that word to search for images in Google. You may find that you have to make room next on your book shelf next to the cephalopod section; nudibranchs look delightfully alien too.)

video
   
Very well, let's now assemble a whole cloakfish with this new swimming pattern. The body assemby is modelled very roughly here, without any details at all. As you can see, I wondered whether cloakfish might be able to change colour? I do not see why not, so here is my first attempt ever of depicting a Furahan animal changing colour. For the technically minded, the colour changes require  two steps: first I wrote a simple Matlab program to interpolate colours between two images, resulting in a new set of images showing intermediate changes. Second, I wrote a python script to get Vue Infinite, the programme I use to render the image, to load a different image to use as texture for each frame. In this case the changes in colour are not that big, but you can probably envisage cloakfish changing colours in much more radical fashion.

video


video

Here is the colour change again, first in close-up, and then in the form of a short scene of a common cloakfish making its way over a reef. Those who are very observant will see that the alignment of the body with the cloak-and-dagger assembly differs between the two animations. The reason for that is simply that I forgot to rotate the body around its longitudinal axis by 45 degrees. The reef scene shows the correct position of the body.

Anyway, clearly and obviously, animations have their own attraction and advantages, such as showing colour changes. How can I ever show a cloakfish changing colour on a painting?    

Friday, 6 November 2015

Progress

I never said I would stop blogging altogether, did I?

The reason I drastically reduced the frequency of blogging was so I would have more time to work on The Book. Well, that approach turned out well. The year is not over yet, and I have produced 11 spreads already. A 'spread' is a double page. I present species and other themes using a double page for each, so it makes sense not to think in pages but in spreads. I expect to finish three more spreads this year, bringing the total of new pages for this year up to 28. That may not seem like much for a book that will count some 160 pages, but it also means that more than one third is completely done, and the rest is about half way there. A big advantage of the increased production rate is that painting becomes much easier if you do it regularly.

Of course, once you stop blogging you should expect to find that not many people will read this post, but we'll see. The point of his post is to let the world know that the Furaha project is far from dead, and to prove it I will show you a few glimpses. Do not expect full paintings though: I will keep those for The Book.

Click to enlarge; copyright Gert van Dijk




I decided that my map making skills needed improvement, so I experimented with various graphic styles and came up with a style that combines shadowing effects with colours indicating height. Of course, a map needs names for places, etc., so there are now a few hundred of those. Here is a fragment of the all-new Furaha world map.

video

Along with the new map I thought about which animals to put where on the planet. I never actually spent any time on that, but now wondered whether it might be prudent to ship off some of the really odd designs to places where they might have developed in isolation. This of course prompted the question which places have been isolated for a long time. So here is something that will not be found in the book, as it is an animation made just for this post. It shows continental drift on Furaha for the period of 200 to 100 million years ago (MYA). In case the changing shapes of the continents confuse you, the change is simply a consequence of the map projection: on a sphere you would be able to see that the continental masses -the yellow shapes- do not change in shape. The blue lines are present-day coastlines, only put there to help make sense of which continent is which. Ancient coast lines are not indicated. They can be quite different. The projection is the so-called 'Eckert IV' one, by the way. All done with Matlab and good old-fashioned trigonometry and matrix algebra.

Ten Borgh with a student. Click to enlarge. Copyright Gert van Dijk
The book will have a 10-page part about humanity on Furaha. This includes social customs, remarks on language, etc. Here is a fragment of a painting showing an expedition led by the distinguished citizen-scientist Ed ten Borgh, famous on Furaha as well as on Earth.

So there you are: the project is alive and well! Will there be more posts? Occasionally, yes.

Saturday, 13 June 2015

Second part of a review of 'Demain, les animaux du futur' (Future evoluton from France II)

In my first review of the book 'Demain, les animaux du futur' I gave an overview of its contents; this second part will provide a broader view.

I have just spent a pleasant day in Paris with the authors of the book, Marc Boulay and Sébastien Steyer, mostly to talk shop. Their book is doing well, and is the best-selling book at present in the nature category in France. Accordingly, the authors are being approached to give interviews quite often. In fact, while we were at Sébastien's place of work, the Muséum National d'Histoire Naturelle (National Natural History Museum), a journalist showed up from Science et Vie. This magazine is in scope probably the closest equivalent in France to Scientific American. Some of the earlier comments on the book also touched on topics that came up in the interview, such as whether the 10 million years that passed from the present to the time depicted in the book are long enough to account for some of the profound changes in body size, shape and lifestyle to have occurred. To answer that, let's have a look at some of the changes the authors envisaged.

Click to enlarge; Copyright Éditions Belin
Ten million years from now, according to the book, giant bats have emerged from the night, so to speak. They are active in broad daylight and have lost three of their five fingers, which makes them look somewhat like pterosaurs. The wingspan of the largest species, Gigapterus tropospherus, shown above, reaches 15 meters for males. This species has dark spots on its wing that help the animal soak up sunlight during the day to use at night or at high altitude. Mind you, the text states that energy is stored through melanocytes, so this is not photosynthesis, just light and hence to a large extent also heat.

Click to enlarge; copyright Éditions Belin
Another instance of rapid evolution is Benthogyrinus giganteus, an amphibian filling the niche of present-day baleen whales. Compared to its present days amphibian cousins it is absolutely gigantic, even longer than a blue whale. It thrives in the seas, something no present amphibian does. The authors are quick to point out that past amphibians like Ichthyostega tolerated brackish water, and they quote Darwin himself, who described a Patagonian frog living in water too salty for humans to drink. But perhaps its most intriguing feature is that the animal is basically a giant tadpole, meaning it is a larva. It procreates as as larva, in contrast to normal tadpoles that have to metamorphose into adult frogs or toads to do so. This process of retaining juvenile characters in adult life, 'neoteny', certainly occurs in amphibians; the axolotl is probably the best-known example. In fact, some of the peculiar traits of Homo sapiens, that's us, also suggest neoteny: compared to adult apes, we have a large cranium, small and weak jaws and teeth, little hair, etc. To my surprise the Wikipedia article on neoteny almost exclusively deals with neoteny in man. It even suggests that Neanderthal man was less neotenic than we are, so Neanderthals represent the 'adult' version of Homo sapiens more than we do. Hmm; is Homo sapiens then in fact just an adolescent version of Man, let loose upon the world without adult supervision? That might explain a thing or two, but I digress...

So how fast can evolution proceed? Some circumstances seem conducive to quick evolution. The foremost is probably a large difference between the demands posed by an environment on an animal's (or plant's) characteristics and its actual traits. If the gap is small, the eventual changes necessary for adaptation will be small too, but we want impressive changes. The required large gap can be bridged by a series of mutations each bridging a small part of the gap, provided each step conveys an advantage by itself. As an example, consider an aquatic life form faced with an enticing new and fresh world beyond the water's surface. If there is anything to be gained from foraying on dry land, such as cheap food or finding a pool that is not drying out, then a mutation that help the animal to accomplish this task will help it to compete with its fellows. A hypothetical adventurous fish making its first clumsy steps on dry ground certainly merits an epitaph such as 'One small step for a fish, but a giant leap for fishkind'. Of course, such a fumbling fish has no advantage whatsoever if dry land is already occupied by agile predators only waiting for the intrepid fish to venture its naive adventure into their territory. The best circumstances for fast evolution may therefore be a combination of, on the one hand, a large gap between demands and capabilities, and on the other hand an empty stage to stop anything impeding runaway adaptive radiation. Those are exactly the circumstances envisaged in 'Demain'.
   The empty stage in the book is the result of the 'sixth extinction', meaning the sixth time Earth witnessed an extinction of a sizeable part of the world's life forms. All were major assaults on life, and the sixth one is is the one that some authors believe we are witnessing right now. But in contrast to previous ones, caused by natural phenomena, the sixth one is caused by Homo sapiens, going about its business with reckless, perhaps adolescent, energy.
   How large the sixth extinction will be is unknown; we are probably just at its beginnings. The authors' scenario considers it to be at least equal to the mother of all extinctions, the one at the end of the Permian. But with the decline of teleost fish and almost of not all mammals, I would guess it is larger still. A nearly complete collapse of the food chains on land and at sea might indeed provide an empty stage for remnant populations to undergo quick adaptive radiation. The remnants in the book, by the way, are not random, but were mostly taken from species with near-ubiquitous representations: birds, bats and cephalopods.
     

Click to enlarge

Above is a photograph (of poor quality, sorry) showing, from top to bottom, Sébastien Steyer, Marc Boulay, and the journalist of Science et Vie, Elsa Abdoun. The locale is the Muséum I mentioned above, and specifically a hall showing a display of present-day whales skeletons, pertinent to the discussion. But why are whales pertinent to this particular book?

Click to enlarge; copyright where appropriate Wikipedia

Whales present a nice factual example of quick evolution. The genus Pakicetus of about 50 million years ago represents a mammal group thought to be the earliest known 'whales', but here that is a cladistic term only: you would not call this mostly terrestrial animal a 'whale' and would probably not call it 'aquatic' any more than you would call a present-day tapir aquatic. But give these 'whales' some time to evolve, and you will encounter the first fully aquatic whales, basilosauridae and dorudontinae, in the seas of 41 to 35 million years ago. What this means is that whales went from terrestrial tapir analogues to fully aquatic animals in only 9 to 15 million years, similar to the 'Demain' book's 10 million years. Of course, the oceans were not empty during this time, so whale evolution might have been even faster on a truly empty stage; even with other players around, whales exploded onto the scene.

Click to enlarge; copyright Éditions Belin

To conclude, what the book does, and does well, is to explore several biotopes. My personal preferences include what the authors did with squids, a clade also radiating to take up niches left by fish and mammals. Above is a giant one, Rhombosepia imperator. It too underwent impressive changes, including the concept that most of its tentacles fused to form false jaws, lined with suction cups. It is, as it was before, a predator, and now uses modified ink to poison its prey.
  I will not show more images from the book: it would spoil the appetite. I realise that readers would want more images, but a review should leave enough unknown for people to want to read the book (this is also the reason why I withhold new Furaha images). I really like the squid radiation, in particular the dolphin analogue 'Delphimimus jamescameroni' (Oh dear Mr Cameron, please have a look at the kind of speculative biology shown here, because it's pretty good!).

The book is not an encyclopaedia of future life; it provides no clues regarding other biotopes. That may be seen as a disadvantage; in a way it is, but I would probably have wanted more even if the book would have had three times the number of pages it has now. Knowing only too well how long it takes to produce such a work, it's perhaps just as well they stopped, to have it published as it is.