Posted on 06/06/2002 12:08:52 PM PDT by balrog666
Evolution and the Spaceport Bar
-----------------------------------
By Wil McCarthy
------------------------------------
What would a Star Wars movie be without its cantina scenes? Ah, that distinctive mix of aliens: weirder and more colorful than your typical Star Trek or Babylon 5 ensemble, but still very familiar. Most of the creatures you see there walk on two legs, and even the strange ones like Jabba the Hutt have a lot of humanoid features, such as hands and eyes and faces and tongues. The question has certainly come up before: Despite their cinematic appeal, are these scenes scientifically plausible?
The easy answer depends on whom you listen to. An optimist will shrug and say, "Sure, why not? We look like that, so maybe all spacefaring species do." A pessimist will take one look at the bewildering diversity of our oceans and rain forests—or the even more exotic creatures in our planet's fossil record—and say, "No way, man. The chance of an alien creature looking like you or me is so remote it's not even worth talking about."
Ah, but a columnist with a deadline—and a word count to fulfill—can be relied upon to take a deeper look. And that's good, because the issue is not as plain and simple as either the optimist or pessimist would have you believe. Why? Because evolution, like engineering or free-market capitalism, is an optimization process which struggles to solve every problem as thoroughly—and yet as cheaply—as possible. The Russian space shuttle looks exactly like the American one not because they ripped it off (although they probably did), but because for that particular job at that particular level of technology and expense, that happens to be the ideal shape.
In biology, this principle is known as parallel evolution, and is the reason why dolphins look like sharks, and the two eyes of an octopus look (and work) remarkably like the two eyes of a mammal. For similar jobs in similar environments, the question of form sometimes has only one right answer.
Before we go any further, let me place some limits on that statement. I am not talking about walking plants, machine life, silicon-based rock monsters, multidimensional entities or creatures of fog or pure energy. If such things exist in our universe—and they may—we have no information about them and can't make too many informed speculations. But on the subject of squishy, carbon-based life forms, we know more than you might suppose.
Symmetry is naturally scientific
To begin with, all of God's creatures are at least approximately symmetrical. Some, like the starfish and the pine tree, are radially symmetric. A few, like the microscopic volvox, are spherically symmetric. Still others are bilaterally symmetric, meaning they have a left and right half which are mirror images of one another. Now, radial symmetry is all right for three-dimensional environments like the open sea, but bottom- and surface- and land-dwelling critters tend to need a top and bottom to their bodies as well as a front and back, and will become bilateral over time even if they didn't start out that way. And once this change occurs, the critters never (or maybe almost never) switch back. For this reason, radial symmetry is a lot rarer than bilateral, and there's no reason to believe this would be any different on other planets.
Also: we know that all creatures ingest nutrients and excrete waste products. This internal chemistry relies on materials and processes which break down with excessive heat or cold, so a finite temperature range is another universal, for all life. Here on Earth, life is utterly dependent on liquid water, in which our delicate molecules are dissolved and suspended. Could life exist without water? Many scientists have explored alternative solvents such as liquid methane or hydrofluoric acid, but water has a number of advantages over any other contender, and is literally more common than dirt in the universe. So the chances are very, very good that aliens drink water just like you and I do.
Moving into more complicated territory, we find a lot of traits which are nearly universal. Almost every life form on Earth has a nose, or at least a set of chemical sensors which alert it to the presence of nearby nutrients or toxins. Similarly, the ability to sense and respond to light is usually a life-or-death issue. And responding to anything—any stimulus at all—requires at least a primitive kind of nervous system. Even single-celled organisms have a "ctyoskeleton" which helps move materials and chemical signals around inside the cell. More complex creatures such as flatworms differentiate their cells into a variety of types, including digestive and signal-carrying cells on the inside and protective skin cells on the outside.
Beyond this point, we can't talk about universals, but tendencies. Life is a rich and complex phenomenon which will always be full of surprises, but it does tend to solve particular problems in particular ways. For example, everything needs muscles (or the equivalent) in order to move. And anything which moves through water or mud or dirt is likely to be streamlined, to minimize the energy it has to expend in propelling itself.
And since most animals eat on the run, it makes sense to place the mouth at the front, with sensory organs clustered nearby. And since it takes time and energy for nerve impulses to travel, it's most efficient to place a brain of some sort right there by the sense organs, and to surround it with protective tissues. This is the principle of "cephalization," the tendency of any organism to develop a distinct and identifiable head—the seat of consciousness—at the front or top of its body. Or the center, in the case of radial animals like the starfish.
Similarly, almost every animal, however simple or complex, has a central "alimentary canal" which connects the mouth to the anus, and includes specialized digestive structures along the way. And unless the creature wants to swim or crawl in its own filth, the "ass end" will normally be at the back or bottom, opposite the head.
Evolution makes the alien humanoid
I think you can see where I'm going with this, but the next tendency is a bit more surprising: the appearance of limbs. From fish fins to chicken feet, limbs and manipulators help animals get around in, and interact with, the world. But where do they come from? The answer, usually, is the mouth. In a complex world full of complex (and often struggling) food, an animal's mouth has got to be more than a simple hole in its head. It needs teeth, mandibles, articulated surfaces or soft, fleshy lips—the more versatile, the better.
And once these clever mouthparts are in place, many animals find new uses for them. Think of a camel's amazingly dexterous upper lip, leading to something like the prehensile snout of the tapir, and finally the elephant's trunk. New limbs often come in pairs, though, and once they're created they often migrate backward, away from the mouth and head, becoming things like arms and legs and wings and flippers. Later, when a creature's lifestyle changes, its unneeded limbs may shrink away, or move back even further to merge with the tail. (There are dexterous prehensile tails, too, but they're relatively rare, while limbs are the norm rather than the exception.) On Earth, evolution hasn't been running for long enough to give lost limbs back to the snake and the eel and the dolphin, but if and when it does, they will probably start at the mouth.
Of course, the aliens in a spaceport bar are a subset of the animal kingdom in general. Specifically, they're land animals from terrestrial planets, with high intelligence, a knack for tool-making and almost certainly a gift for language. On Earth, there are smell languages and color languages and gesture languages, but most land animals communicate with sound, simply because it's omnidirectional and carries over long distances.
So really, scientifically speaking, most cantina aliens are going to be bilateral critters with heads and eyes and mouths, with the chatter of spoken languages, with dexterous manipulating limbs and separate, powerful locomotive ones. If we take the number of eyes as a cosmetic detail, then really the only question is: how many limbs are we talking about? And if the meaningful answers are four, six, and many, then the majority of our aliens will be built on the bipedal plan of Earthly apes, turkeys and velociraptors, or the quadrupedal plan of the praying mantis and the mythical centaur.
Does this make them "humanoid"? The question is semantic and largely irrelevant; in the vast majority of cases, the drinks will go in at the top, where the eyes and mouthparts are, and come out somewhere near the bottom. One wonders how many different kinds of toilets there are in the spaceport bathroom! Anyway, in case of trouble, kicking the offender's legs out from under it will generally bring it down, and if that doesn't do the trick, most animals will respond to restraint of, or threats of violence to, their manipulators. And if all else fails—as it often does in real life and Star Wars movies alike—then a chair or blaster or lightsaber to the head—any head—will end most arguments on the spot.
And frankly, that's human enough for me.
----------------------------------------
Wil McCarthy is a rocket guidance engineer, robot designer, science fiction author and occasional aquanaut. He has contributed to three interplanetary spacecraft, five communication and weather satellites, a line of landmine-clearing robots, and some other "really cool stuff" he can't tell us about. His short fiction has graced the pages of Analog, Asimov's, Science Fiction Age and other major publications, and his novel-length works include Aggressor Six, the New York Times notable Bloom, and The Collapsium.
-------------------------------------
Also, I would like to suggest that we add a Topic on Science on FR.
More seriously, read Wolfram's book A New Kind of Science. It will give you a new perspective on problems like this.
I loved Babylon 5 - intelligent writing, interesting characters, continuing storyline with ensemble cast, and very little PC horsesh!t. I also like Farscape for the same reasons. There's a lot more of the rubber-mask-alien costuming but they add puppets to offset it.
Babelfish?
Translator microbes?
Too many reruns?
In a complex world full of complex (and often struggling) food, an animal's mouth has got to be more than a simple hole in its head. It needs teeth, mandibles, articulated surfaces or soft, fleshy lips—the more versatile, the better.
And once these clever mouthparts are in place, many animals find new uses for them.
Evolution is truly amazing. Here we have a mouth with no way to get food into it. Yet it survives as a species for billions of years until it can develop limbs to feed itself so it won't starve to death. I suppose before it develops limbs it pulls itself along with its lips or tongue until it lands on food it can eat.
Science marches on!
GUY AT BAR Yeah, this guy digs me.
JOHN HURT spits out some of his food. They lie him down on the bar. LONE STARR and BARF look and react.
WOMAN AT BAR Bring some water.
GUY AT BAR Water my ass. Bring this guy some Pempto Bismal.
BARF Waitress! Waitress, what did order?
The WAITRESS comes over to BARF. She looks over to JOHN HURT.
WAITRESS Oh, he had the special. BARF The spec.... That's what I ordered. Change my order to the soup.
LONE STARR Good move.
Something is trying to push out of JOHN HURT'S stomach. It eventually comes out. A little alien comes out of his stomach.
It growls. JOHN HURT looks at it.
JOHN HURT Oh, no. Not again.
The ALIEN jumps out of his stomach on to Spaceballs-the Placemat. Some people scream. The ALIEN growls again. Then, it puts on a little hat and starts to dance down the bar.
ALIEN Hello, my baby. Hello my honey. Hello my rag-time gal. Sonny my pitched my wild. Baby my heart's on fire.
Tonight on at RadioFR! June 6, 2002
9:00 p.m. - 11:00 p.m. EDT / 6:00 p.m. - 8:00 p.m. PST...
YO!
ANNA AND MERCURIA
DO THE "REYNOLDS (W)RAP"
(Well, you knew it had to happen sometime...!)
WITH SPECIAL GUEST
DAVID PALMQUIST
"THE KING OF CONSPIRACY"
I have, and I do.
--Boris
With respect to Star Trek, the Universal Translator. How it's database had linguistic info on supposedly "new" alien race, I haven't a clue other than TV magic.
I will reserve judgement on their hypothesis until their sample size is larger than 1.
It sure is. Of course, you have use your brain for more than a paperweight.
Red Dwarf rules!
Besides there are others far more qualified to perpetuate the debate than I.
You're right! The only problem is I can never find it! I've seen three episodes...classic...as good as Blackadder!
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.