Saturday, 28 August 2010
Adding oddity (alien plants II)
I don't write often on alien plants, for a simple reason: there seem to be few of them. I wrote about the -real!- plant life on the island Socotra once, shown you Furahan swamps and showed a few images from the British comic strip Dan Dare. My main post on alien plants was devoted to a computer-generated video. The firm that made it produced another one, as I learned from a site called dexigner.com. The images shown here and the video are taken from that site (the video quality on the site is very good). In fact, there I learned that the previous one was called 'Sixes Last'; there are so many copies of it on the Internet that it is not hard to find it, but it is hard to trace its origin. The 'new' one dates from 2006 and is a commercial for an alcoholic drink. I have nothing against that; in fact, C2H5OH plays quite a role in Furahan biochemistry. As 'advertisement' is not exactly a synonym for 'accuracy', do not expect much in the way of plausibility. Then again, the film does not try to be accurate, just intriguing and humorous. It succeeds well, I think. The computer-generated bits seem to be added to real footage, which may explain why the images look very real.
The second reason to show it is to discuss the problem of how to design odd plants. I have this worrying idea that the basic plant design may not allow much creative freedom, at least not if the definition of plant is not stretched too much. The main ingredients of the definition may be photosynthesis and being sessile, with some -arbitrary- limits in that the plants in question are multicellular and that they are land plants. Photosynthesis needs light, and the best way to get much light is with a large area, i.e. thin shapes. Needles are good but planes are better. Basically a blanket-like shape with roots to pick up minerals and water is all you need. But if the blanket gets too large it may be torn by the wind, and an easy way to avoid that is to distribute wind stress over many small leaves. Growing towards the light avoids being in the shadow of other plants. Branching systems and leaves seem unavoidable, and any alien plant with those will look like an Earth plant.
What can be done is to alter the relative sizes of plants: thick stems, enormous leaves, etc. and giving them odd colours. But there are usually reasons for these proportions as well as for colours, so there is no total freedom here. The simplest way to add oddity may be to add elements of animals: give the plants eyes or mouths. That is what happened in the earlier video as well as in the present one. Eyes are there to tell an organism about its environment: where is the prey, where is the predator, are there good-looking potential mates around, etc. Acquiring information is only useful if you can act on it, and the main limitation here may be the sessile lifestyle. Sessile life forms can certainly be interesting; there are quite a few sessile predators: think of anemones. But there may be a limit on how well developed their sense organs and brains can become. Why have fine eyes and precise grasping arms when your reach remains frustratingly limited? Wouldn't an animal that can do the same things but that can move around be vastly more fit in the evolutionary sense? You may counter that by saying that it may be enough to outperform the dumb and blind types of sessile organisms. In evolutionary biology traits always seem to cost something. The price to pay may be a metabolic one: eyes, muscles and particularly brains are very expensive in terms of energy.
In that sense, high class eyes are jetset organs, reserved for high flyers only. So the puzzle remains how to increase the oddity of alien plants...