by Quentin Long
©2008 Quentin Long
Communication: Its something that pretty much any sentient species is going to have to do. Of course, that doesnt mean any two sentient species are obligated to communicate in the same manner!
But however a given critter goes about it, communication involves copying concepts/ideas from one mind to another. And since direct mind-to-mind thought-transference (i.e., telepathy) isnt a viable option, that means encoding said concepts/ideas into a set of symbols in a physical medium of some kind, bringing those symbols to the attention of another sentient, and letting that sentient decode the symbols.
In the case of the species homo sapiens, one could argue that the primary mode of communication is complex patterns of acoustic vibrations generated by a specialized set of bodily organsthat is to say, spoken language. From an engineering point of view, sound has a lot going for it as a medium for communication; for one thing, making noise is cheap (in terms of energy-cost) and easy. Sound being omnidirectional, sonic-based communication doesnt require precise targeting on the part of either the sender or the receiver. Its versatile, being equally suited to communicating with one sentient privately or a whole mass of sentients collectively. The bandwidth of soundits information-carrying capacityaint so bad, either! And note that us humans are far from the only species that exploit sound for this purpose; think of bird song, wolf howls, whalesong, etc.
All in all, its a good bet that lots of sentient species will use sound as a substrate for communication. Which isnt to say that it will necessarily be easy for two sound-using species to comprehend each others sonic communications! If Species A cant even hear the noises with which Species B communicates (to cite only the most obvious possibility), thats going to be a nontrivial obstacle to understanding. As well, keep in mind that communicating must necessarily involve some sort of scheme for associating concepts with symbols; all such schemes are fundamentally arbitrary, which means none of them can be deduced from first principles. Which, in turn, means its quite possible that even if Species A can hear the noises Species B makes, they may not recognize those sounds as a form of communication!
Naturally, sound isnt the only possible communication-substrate. Light can also serve. For sentients that live on a planetary surface, theres plenty of electromagnetic radiation to exploit; for critters whose environment has little-to-no ambient illumination (i.e., caves, deep sea, etc), light-emitting organs can be a viable option. Mind you, light may not be as good a choice as sound. To generate sound, all a critter really needs is a physical body; to generate light, a life-form needs some sort of biochemical system thats specialized to do exactly this thing. And while light-based signals may have a near-infinite maximum range, sound-based signals arent blocked by smoke, haze, fog, or solid matter
In homo sapiens, visual communications includes American Sign Language, gestures, and the written word. Since these options work for us, theyre obviously live possibilities for other species, too. However, they arent the only forms of vision-based communication that might be used! Many creatures can alter their general appearance, for instance by making their fur (or feathers) stand on end so they look bigger than they actually are. If youre a non-sentient critter, you might do this as a threat display, to discourage other animals from attacking you. But if youre intelligent, sophisticated control of fur-raising might well become the basis of a form of communication.
In this context, its interesting that fur isnt necessarily a one-level thing; there can be longer guard hairs and shorter underfur. Depending on how fine-grained a creatures control over its fur is, this means fur-raising could conceivably let that creature display three different colors! With all hairs down, you see only the guard hairs; with only the guard hairs raised, you can see the underfur; with all hairs raised, the creatures actual skin-color becomes visible.
And then there are critters like the chameleon and octopus, which take color-changes to the logical extreme. If one of these species had intelligence, is it really so implausible to think that its members might use organized color-patterns to express their ideas, just as we humans use organized sound-patterns for exactly that purpose?
The senses of smell, taste, and touch are not well-suited for use as bases for communication. Touch and taste, in particular, are very short-range; communication based on either of these senses would pretty well require being in close physical contact all throughout the entire conversation. Nevertheless, if youve got a perfect storm of exactly the right combination of environmental factors and evolutionary history, its at least conceivable that an intelligent species might use a smell-, taste-, or touch-based mode of communication. If youre thinking about creating such a species, keep in mind that the aforementioned perfect storm has to explain how come your species managed to avoid developing sound- or vision-based communications.