Saturday 25 May 2013

Predatory penguin's evolution in Brussels' future evolution back on course.

Regular readers may have noted a predilection for incomprehensible titles, or let's say titles that need a lot of knowledge to be comprehensible. This one fits that bill, I think. The previous post dealt with models of future animals in the Brussels museum of natural history. One thing that struck me was that the model of a Neopygoscelis, a penguin descendant, differed quite a bit from the earlier published design. The feet had expanded at the cost of the flippers, an evolution that I would not have expected. The designers, Marc Boulay and Jean-Sébastien Steyer, explained that the actual models had been produced without much control by themselves, explaining the changes. Marc and Sébastien are working on a book about future evolution that will appear in 2014, as told here previously (you can read starting here or here).

My discussion of the odd 'evolution' of the Neopygoscelis model persuaded them to send me two photographs of Neopygoscelis as it will appear in the book, meaning 'Furahan Biology and Allied Matters' gets another exclusive preview of that work.

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The photograph above shows clearly that the model maker had evolved the enormous hind legs of the museum model quite separately from the designers' ideas. The ratio of flipper to feet size clearly shows that the flippers are still the primary propulsion method of this animal. The feet with their long nails do look formidable though, but not as a propulsion organ. The eyes are large, so the animal does not seem that large to me; the size of 4 m as stated for tye museum model seems too large for this particular animal. Note that the nails differ in size between the two animals, so I guess that we are looking at sexual dimorphism here, with one a male and one a female. I do not know which one is which, though: Marc and Sébastien sent me the photographs, but no accompanying text. That is probably wise: always leave the reader wishing for more...

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The image above shows a pair of Neopygoscelis in their habitat in photorealistic mode. A very nice addition. So there are now three versions of Neopygoscelis: the digital illustration  originally shown in the magazine, the grey model in the museum that we should probably regard as a largely 'unauthorised' version, and the one in this post, that will make it into the book. That is, unless the designers feel a last-minute need to change something before the book goes to press.

I have in the past reworked oil paintings, sometimes more than once, but doing so was a big job: it involved scraping off layers of paint before adding new ones, so the process was quite destructive. Working digitally means you can do the same thing without losing anything. Most older Furaha animals were designed for visual attraction than a coherent body plan, but I am remedying that slowly, whole keeping visual appeal intact -in fact I try to improve it-. There is always a temptation to go back and push and pull at a design some more. Obviously, the same temptation works for the designers of 'Demain: les animaux du futur', but there is one big difference: there is a publisher, so there is a deadline, and so at some point the image is finished and you cannot go back any more; what a luxury.

I can't wait for the book. When it appears I will write about it here, and perhaps earlier than that as well...  

Friday 17 May 2013

Back to future evolution in Brussels

In 2009 I wrote about a paper in a Belgian magazine showing models of future animals in the Brussels Museum of Natural Sciences. The animals later also appeared in Darren Naish' Tetrapod Zoology blog. For me, discovering the Brussels animals had as an unforeseen effect that I got to know the makers of the models, for whom designing future animals proved to be more than a single occurrence. Marc Boulay and Jean-Sébastien Steyer have been working on a book on future evolution at least since 1999. The book will be published by Belin in 2014 (in French). There are glimpses of animals as yet unseen by others on Marc's site, by the way.

Back to the future, or back to Brussels, whatever the case may be. I have now finally visited the museum; it is quite good as Natural History museums go, and specialises in dinosaurs. There is an impressive display of nine mounted specimens of Iguanodon bernissartensis, and that alone should be worth the visit. Belgium is famous for its rich supply of Iguanodons, found around 1878 in a coal mine.

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As you can see, the Iguanodons are standing upright in the tripod position favoured at the time when the skeletons were mounted in 1883, not with their vertebral columns and tails horizontally as would be the case today. This is not because the museum is not up to date; it is  as far as I can tell, so I suppose they are just wary of the cost of remounting various very large dinosaur skeletons. Or perhaps there is a risk of harming the priceless skeletons, or perhaps there is an historical continuity in keeping the Iguanodons mounted according to yesterday's ideas.

The museum has a gallery of evolution, illustrating some major events and their consequences in evolution, such as the developments of eyes, of jaws, of armour and fins. There is a nice video illustrating evolutionary branching, ending for once not with man on top but with many species at the same point in time; if any species is singled out, that is -jokingly- a penguin! At the very end of that gallery there is a small group of models, and those are the animals of the future. That part of the exhibition is rather small and has not got much in the way of explanation. There is a video showing continental drift for the next 50 years, but that is about it. There are no plaques stating what is special about these animals. In fact, I saw a group of children walk by, probably ignorant of the fact that there were fundamental differences between these displays and the multitude of stuffed animals in the museum. There was a sign saying that some items had been removed from the display because of changes being made to the room's climate system; as far as I can tell a snake and a gliding mammal (Trichopteryx dixoni -surely I do not need to explain who that animal is named after-) were missing. Perhaps this also explains the lack of explanations. In this post I will add some explanations, obtained in part from the interview with Jean-Sébastien Steyer in 2009, and to a larger extent directly from his and Marc's comments on a first draft of this post.

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Corticochaeris gouldi
This is a descendant of the capybara, today's largest rodent. It has become larger, with a disproportionate growth in its teeth, head and front quarters. The magazine text states it is a forest dweller, and its colours seem quite appropriate for that, mimicking spots of light falling through a leaf cover.

I had not seen the species' part of the various names before, as these are only mentioned on small plaques in the museum. The species' names reveal something about the designer's taste in biology and illustration, so they deserve mention. The name 'gouldi' is an homage to the late Stephen Jay Gould. He is considered one of the best writers popularising science of the last century, so I am glad I the designers must have felt similarly.

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Propellonectes russelli
This is a one meter long descendant of the Northern Giant Petrel, Macronectes halli. As you can see it has evolved into a large flightless swimming bird, propelling itself with its feet by way of flaps on the toes that no doubt fold back with the feet are pulled forwards and that spread out when the feet move back. 

'Russelli' denotes Dale Russell, the Canadian palaeontologist who proposed that dinosaurs might have evolved into an intelligent dinosauroid.

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Neopygoscelis dentatus
This is a toothed descendant of the penguin species Pygoscelis papua, so its formal name means 'toothed new brush-tailed penguin'. The teeth are apparently not just serrations of the edge of the beak, but proper teeth: the magazine interview states that birds still have the genes for teeth, and that it is not impossible for these genes to regain their expression. Neopygoscelis is an impressive four meters long. Its feet have evolved into large paddles and its wings/flippers have decreased in size, it would seem. That is odd: current penguins have very efficient flippers, so I wonder whether their continued evolution would promote feet at the cost of flippers. The animal appears not to need to climb ashore any more, which would certainly free the feet from their current restrictions as walking appendages. That would make them susceptible to evolution in another direction, but a drive towards them serving as propulsion aids has to start with a propulsion advantage right now, not a future advantage its descendants may gain from enlarged feet. Because of that, I would expect the flippers to stay in place as near-perfect propulsion limbs, and the feet would, well, what would the feet do? Turn into rudders? Disappear altogether? Turn into sexual aids? (In zoology that can always happen...)

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In the magazine, Neopygoscelis was shown in a penguin-like black-and-white coat (top), but in the museum it is an overall grey colour (bottom). With the magazine in the one hand and my photographs of the museum version in the other, it became clear that the two do not represent the same model at all! Jean-Sebastièn and Marc explained that the process of having the digital designs converted into an actual model had to be done in a hurry to get the models ready for the opening of the exhibition. The result of this was that there was unfortunately not enough opportunity for interaction with the model maker, so the museum models ended up rather different from the original designs. I suppose that that explains the 'feet vs. flipper' exchange in size, which probably reflects a choice of the local model maker. 

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Helicopodus buriani
For this species and the next, there is nothing in the paper and no explanation in the museum. The model confused me a lot: I could see that it has a segmented body and jointed exoskeletal legs, so it can only be an arthropod. Still, its head looked very unfamiliar, and its eyes certainly look like camera eyes, although it is hard to be certain. Again, it appears that the design suffered from a lack of time for cooperation between the designers and the sculptor. Luckily, I had help from the creators of this odd animal: what we have here is a centipede with a flattened body allowing it to glide through the air. Now that is a neat invention; of course, animals from very diverse groups developed gliding forms, including mammals, lizards, squid and insects, so why not centipedes?

It really is a pity that the museum provides so little information, not even stating that the animal is a glider! (This is a pet peeve of mine: why do museums usually only provide meagre information at infant level? With modern media it should be possible to provide information on many levels, so visitors should be able to choose the level and extent of information they want!)      

'Buriani' refers to Zdenek Burian, whom I consider to be one of the world's best painters ever of prehistoric life forms (and I am not alone in this).

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Rhombosepia gregaris
The shape and name help here: the 'communal rhomboid-shaped squid'. These are apparently  descendants of cuttlefish swimming head first instead of backwards. Drawing attention to 'swimming head first' may seem strange as it seems the normal direction; true, but squid generally swim with their tentacles trailing them, meaning that anatomically they swim backwards. In fact, many can swim either way. Swimming with the tentacles pointing the way means the tentacles have to be pressed together to form a smooth surface so as not to impede movement. As far as I remember, the thing about Rhombosepia was that its tentacles had fused. I did not check that with its inventors, but relearned that from people commenting on my own blog, who had followed links towards more information on this variant of future evolution. When I checked now, many of those links did not work any more. Those posts were only a few years old, and yet the information has been lost already. With such a quick loss of information in mind, perhaps the guardians of the Brussels museum did well in keeping their Iguanodons in their old-fashioned tripod stance. Concepts of Iguanodon stance are no older than about 125 years, but the skeletons have been underground for more than 500,000 times that length of time.

Having said that, I still find it very difficult to wait for about ONE more year for the book showing us these future animals...

Saturday 4 May 2013

Inversion fish I

In November 2012 I wrote about thomastapir's 'Xenohox Gazelle', an extremely original concept for alien animal locomotion. In that post I also mentioned that I might write about another of his inventions, the equally creative and original  'Moebius fish'.

Click to enlarge; copyright Thomastapir
The Moebius fish consists of a body sitting like a node in a complexly folded ribbon. The ribbon folds in upon itself, resulting in a complex movement. Please read Thomastapir's own descrition on his DeviantArt page, using the link above. I wish there was an animation though, as I would dearly like to see which part goes where. Luckily, the German firm Festo has produced a flying inversion device, wit a perhaps similar movement. Festo is a technology firm that often plays with biologically inspired designs, such as helium-filled balloons moving like jellyfish or manta rays. Their most recent devices include a robot flying like a dragonfly.

Festo's inversion device is shown above. This too is a helium filled balloon, shown to turn inside out in the air. It is remarkable difficult to understand what you are actually looking at. I will come back to such complex inversion shapes in a later post; the basic design consists of a series of tetrahedra (a tetrahedron is a four-sided object, with a triangle for each side). In the Festo 'inversion cube', the tetrahedra are connected to one another to form a ring. When I first saw the Festo film I immediately wondered whether that intriguing movement could be used for animal locomotion; thomastapir had already designed his Moebius fish by then though!

The whole concept of inversion shapes is interesting enough to consider how it works in a bit more detail. I will not tackle the complex shapes in this post, but will starts with the easiest version I could think of. I will call them 'fish', using that word in the time-honoured but zoologically incorrect fashion meaning 'animals regardless of descent, nature or shape, with as the only shared characteristic that they live in water'. The Festo animal is in fact a ballont, and there is no strong argument against such creatures floating in air rather then water on other planets; having them swirl around in water is so much simpler however that that is where I will put them.

The basic shape is a ring that inverts itself, so after a bit of programming here is a very simple version: a ring that continually inverts itself. I do not think that this flat shape lends itself well as a Bauplan for an animal, but give it a bit of thickness and there is room for muscles, say for starters circular muscles running lengthwise along the two rims. If one of the  two ring-shaped muscles contracts, that rim will contract and will tend to move inwards. Alternate the movement and you might get something like the 'ring fish' above.

It doubt that the animal has much to gain from the movement though: when the outer part of the ring moves downwards, that part will provide an downwards thrust, but at the same time the inner part moves upwards, providing an upwards thrust. The outer part has a larger area than the inner part, so perhaps there is a net downwards thrust, but the movement cannot be particularly effective. I wonder whether this also holds for the Festo thingy: the video is not too clear about it actually moving through the air, although it obviously moves in the air.

Let's give the 'ring fish' a bit more body. Its shape is now a torus with a triangular cross section. It is intriguing to see the movement. Again, the animal can be equipped with muscles running lengthwise around its body in the corners of the triangle. By contracting and relaxing them in the right order the fish could turn itself in and out continually as shown here. Perhaps shorter muscles running at right angles between the three ridges might help in contracting the successive ridges, to result in the inversion movement. But will it move through the water?

A natural development is to add more details, turning the torus into a smooth-skinned shape. The one above has a pentagonal cross section. The muscle arrangement would still work to make it turn inside out, but as the sides become smoother it becomes ever more clear that the inside-out movement, the 'inversion', is by itself not a sound propulsion device.

To achieve that we need a trick. Equipping the surface with something that provides traction, such as fins, would do the trick. Here, I added simple lines to the inversion fish. If the animal is microscopic the lines may stand for hairs, and at that scale hairs do provide propulsion. Lots of microscopic animals on Earth use hairs ('cilia') for that purpose. Note that the cilia do not always simply stick out from the surface, but move depending on the phase of the movement. The cilia are swung back during the upstroke so they do not provide much of a downwards force then, but they stick out during the downstroke, providing an upwards force. I assume that the animal could reverse its thrust to sim down, and if it turns on ist sde it can move horizontally. I animated just one ring of cilia, but there could easily be lots more, providing continuous force. For larger animals, change the lines into shapes with a bit of surface area, and there you are: the 'hedgehog inversion fish'.              

This design is not without its problems, unfortunately. The biggest problem is probably that it is none too obvious why they move in the way; this is rather a big problem, but I will largely ignore it -for now- . Their bodies are distorted greatly during movement: just have a look at the rectangular outlines on the body, and compare a rectangle on the inner aspect of the torus with one on the outside: to turn one into the other much stretching and squashing is needed. Some animals can do that, of course, such as octopuses, but all this distortion must limit the design severely. One way to avoid that would be to add a node to the torus that does not change shape, to house things such as a brain etc. Thomastapir's Moebius fish has such a body, and if I understand the design correctly, the body does not rotate. But if I were to equip the torus designs above with a body by just gluing it to the torus,  that body would still rotate along with the torus, so any eyes there would have to cope with a continuously rotating world view. The squashing and stretching can be solved completely by doing away with the torus and substituting a series of tetrahedra, as in the Festo device, but that is something for another post.