I can't recall if was Nova or something on the Discovery Channel, but some months back I watched a most interesting program about the possible forms that alien physiology might take. One of the first things they zeroed in on was the depictions of aliens in science fiction movies, and particularly the stock UFO-traveling alien as depicted on the cover of Whitney Strieber's potboiler Communion some years ago and has since manifested itself all over the place, including a face on guitar picks.

Most of these depictions reveal a certain lack of imagination. They all pretty much follow a familiar pattern: two large, dark eyes more-or-less horizontally centered in the face, a nose slightly below and between the eyes, and a mouth below the nose, with ears on each side of the head. This is subject to many variations in detail, but—what gives us the idea that an intelligent (or otherwise) alien will evolve along this same pattern?

The internal organs of the dolphin are very similar to those of humans, or so I have read. The lungs are practically indistinguishable from those of human lungs, and the brain is a bit eerie: about the same size, and with the same kind of convolutions as that of a human brain. There are those who suspect that dolphins are far more intelligent than most people think, and our ideas of intelligence are prejudiced by our own predilections—and limitations. Dolphins may be highly intelligent, perhaps even more intelligent than we are (Douglas Adams had a nice riff on this in Hitchhiker's Guide to the Galaxy), but they are just not technological. They are well-suited to their environment and don't really need to be technological. They are social, and they do communicate with each other. Perhaps they are poets.

Anyway, as closely related as humans and dolphins are, and as similar as we are internally, there are many differences by which they are well-adapted for living in a marine environment. Instead of breathing through a nose as we do, they breath through a "blow-hole" at the tops of their heads. If we want to share their environment, we have to go to a sporting-goods store and buy a snorkel. They're born with one.

The octopus, to which we hardly seem related at all, has shown signs of a pretty high level of intelligence, and I know of at least one occasion where a captive octopus, kept in a tank in a laboratory for study, regularly managed to outwit his keepers, get out of his tank, and go walkabout in search of a midnight snack. The scientists first began to suspect this when they notice that the number of specimens in other tanks began to diminish. And that's not all that these bizarre creatures seem to be able to be able to surprise us with.

So if we can't seem to determine the intelligence level of many of the creatures we share a planet with, if we come face to face . . . or whatever . . . with something really alien, how are we going to know if it's intelligent or not? I doubt that it will step up, shake our hand with one of its tentacles, and say, "Hi, there! My name's Bqrftzxck, and I'm form what you folks would call Arcturus Five. What's your name?"

The physiology of any living entity is going to take a shape dictated by what is necessary to survive and thrive in the environment in which it evolved. And whether it develops intelligence or not will depend a great deal on the kinds of challenges it meets as it evolves.

Here's a thought:   in the movie "Alien" and it's sequels, the alien seems to be some sort of insect cum reptile analog. We know that the alien creatures have a reproductive biology much different from ours (more like that of asp-wasp), are endowed with a great deal of animal cunning, and are extremely dangerous. But we never learn if it's intelligent or not. Contrary to many science fictions movies, this particular alien is pretty alien, and is fairly well realized. Not just someone from central casting endowed with a lot of sponge rubber and nose-putty.

There may be life all over the Cosmos. My guess is that intelligent life may very well be out there, but it will not be all that common. For example, the shark was perfectly adapted to its environment millions of years ago. There isn't much around that could challenge it, so it didn't evolved much in all that time. It's still pretty primitive. Humanoids were weak and vulnerable compared to the other predators in their environment, so the only way they (we) managed to survive was to get smarter than those other predators, and learn to work cooperatively.   [By the way, we're still not real great at that yet.]

Can somebody give me a good reason why a Martian sea creature would evolve a shell that looks like the shell of an earth sea creature? That, just by itself, should raise questions. .

Astrobiology is absolutely fascinating.

Don Firth