Sunday, 28 June 2009

Go, tetropters, go! (tetropters III)

In my last post on tetropter flight I tried to find some kind of proof that the way I imagined tetropters to fly is valid. Just to make certain everyone knows what tetropters are about I will provide two rough sketches of what tetropters look like:


A tetropter on the verge of being snapped up by a tetrapterate

A few examples of tetropters in flight

I turned to the world of 'micro air vehicles' for proof, but had to end the post with a question, as I could not find solid proof that a similar flight mechanism had indeed been invented.

Luckily, I can now report that there was indeed such a flying vehicle: the Mentor, and it flew in 2002! I emailed Roy Kornbluh (see the previous post), and he was kind enough to confirm that each of the Mentor's four wings clapped against both of its neighbours. Moreover, he directed me to a website with footage of the vehicle in flight. If you want to see it at its original place, you can find it here.

But you can also simply admire it here:

video

So the radial flight principle has been proven!

That does not mean that tetropters must exist on other planets. But my hypothesis is that they could, and that their mode of flying makes sense depending on what you start with. Perhaps ancestry is the simpleanswer to the question what determines whether evolution produces radial or bilateral flying body plans. Animals with bilateral symmetry that take to the air will probably end up with bilateral wings. All animal groups that evolved flight on Earth (insects, pterosaurs, bats and birds) started with a bilateral body plan in the first place. But if animals such as starfishes had gone for a more active mode of life, and had made it to land as well, perhaps their descendants would have made it into the air. If so, they would have started with a radial body plan. If evolution had taken this course, perhaps there would be animals with radial flight on Earth right now. For now, it's just machines.

14 comments:

Anonymous said...

guaauuu es genial.............. ami me gusan mucho tus criatras..
sinseramente matias palma

Josh said...

I'm really amazed at the ingenuity of tetropters. Are they by chance related to the spidrids? Since they both seem to be radial symetric arthropods.

Sigmund Nastrazzurro said...

Dear Anonymous: un placer.
Am I right in thinking that 'guaauuu' means 'wooof!'?

Josh, definitely. I played with the idea of having animals with a radial body plan, and the spidrids and tetropters were the result. But they do not have the same ancestry, or, in other words, I haven't thought about that musch. Spidrids have eight limbs, and tetropters have four wings and some legs (I haven't even worked out how many yet).

Josh said...

I thought perhaps if tetropters evovled from ancestral spidrids that four of limbs could have become wings while the other four could have remained for walking.

Sigmund Nastrazzurro said...

That's a definite possibility, and one that makes sense.

There are other possibililties too: the archetypal limb in Earth's arthropods is 'biramous': it has two brac=nchges. In some one branch go lost, and it others one branch became a gill and the other a walking leg. Such an arrangement might even leave a tetropter with eight walking legs and four wings.

Spera said...

At any rate, I liked some of the vadlo science cartoons!

Dinoboy said...

Ingenious, reminds me greatly of those wind-dispersed seeds that one often sees growing on certain trees (pardon my inability to name the species). As to the question over the number of limbs these creatures might have, I think that the minimum (and maybe most useful) number would be four, though I have little idea of the usual amount on Furaha. Pardon my asking but what would press these animals to evolve one-way flight? I don’t think they’d be very useful for a getaway, since as soon as it landed the Tetropter would become very vulnerable to predatation once more. But perhaps I may be missing some crucial piece of information (again ☺).

Dinoboy said...

For some reason whenever I see the Tetracopter sketch, I immediately think "pollinator". I must say it again I love the design!

Gert said...

Hi Dinoboy,

Thanks for liking the tetropters. But what do you mean with one-way flight?

The tetropter flight patern certainly allows them horizontal directional control. Think of dragonflies and the like: but subtly twisting thei wings, they can control their flight in various directions. The only thing you do not see them do is suddenly flying sideways.

That's no problem for a tetropter, so, if anything, it is more manoeuverable than Earths' flying forms.

And as for danger while being on the ground, yes, but that holds for all flying animals. It's the quick getaway that gives them an advantage.

Dinoboy said...

How embarrassing, again I have failed to read all the posts pertaining to a subject before commenting! I definitely need more practice with blogs.
As for the matter of "one way flight" I got to carried away by the similarity of Tetropters to those aforementioned spinning seed pods.
I promise next time I'll read everything before posting!
P.S. Are there any animal pollinated plants on Furaha (I'm a mite too lazy right now too see for myself)?

Anonymous said...

Hi Dinoboy,

Actually, the plant life is rather sketchy, but yes, I think there are pollinators: it is too good a scheme not to have!

But seriously, I think that it is likely that a plant-animal symbiosis in which animal pollinate plants and get food in return makes such good sense but it may well be a universal evolutionary principle.

Sigmund Nastrazzurro

Dinoboy said...
This comment has been removed by the author.
Dinoboy said...

Is it possible to have an ecosystem that is not entirely bacterial were plants are not as common as here on Earth? I know Antarctica has few (perhaps no) non-aquatic plants but I mean no plants on a larger scale. Maybe the very bottoms of this vegetation deficient food chain would extract nutrients from mineral rich rocks or dirt (compromised of decomposed animal matter) in the absence of plants. I guess the planet would be quite barren with only rocks and perhaps a few pockets of dirt.

Just musing,
Dinoboy

j. w. bjerk said...

One of the most original AND plausible alien ideas i've ever seen. Wish that i had thought of it.

My guess is that tetropters would (all other things being equal) be slower is forward/upward motion than more traditional flyers whose wings are primarily designed to move the creature in a single direction. But they probably have an advantage in general manuverability