Is that an..alien?

[Myasishchev]

I rather think that the definition of ridiculous is claiming that natural selection doesn't exist, and that evolution is totally random and not determined by competitive pressures.

 

[Christopher]

^That's actually rather interesting regarding elephant intelligence, as I'd forgotten about them. Elephants in and of themselves are not good candidates for advanced technological civilization, but I suppose something could arise on another planet elephantlike in its form. But it would have to change significantly.

That goes without saying. Just as we had to evolve from earlier forms that were less well adapted to technological civilization. The point is that the potential is there. The point is that a primate is not the only animal in the universe that could possibly develop into a technological species.

Besides, you didn't say "advanced technological civilization" in the post I was responding to. You said "sapient, tool-using life." Which is a much broader category.

That said, you make a good point: something like a proboscidean culture exists, and could become more with some modifications. But I suspect those modifications would make them more human than less--a bifurcated trunk, sweat glands, smaller size, and ultimately somewhat more intelligence, particularly in symbol manipulation, than they have.

But they'd still be quadrupeds whose manipulative organs come out of their heads. That's not something that could be played by an actor in latex makeup. Yes, there are certain traits that one can assume are likely to arise in species capable of advanced technology, but they don't all have to be shaped like us.

Just kidding--as I was speaking of terrestrial and not marine life, I left cetaceans and cephalopods out of it. If we bring marine life into it, I would not be surprised if this planet or another has produced or eventually produced a sapient language and tool user similar to an octopus or cuttlefish. Unfortunately, it seems that their environment might preclude technology much more advanced than a anti-stonefish oven-mitt--but that might be rather close-minded of me. The dudes in the Abyss seemed to do alright.

For speculation on how an aquatic species might develop advanced technology, I'd suggest taking a look at my novel Star Trek Titan: Over a Torrent Sea.

Yet we mastered the Earth while other apes and elephants face ecological catastrophe. Why? Because we have the ability to understand and produce symbolic tools like language and to create and control physical tools like internal combustion engines.

But that didn't happen because of some kind of innate superiority of the primate form over the proboscidean form. It only happened because we got there first, because the random evolutionary and climatic processes in our history happened to give primates an edge.

Evolution isn't directed. In the individual case, it's random. But in the aggregrate, through sheer numbers evolution tends to produce results that are rather excellently adapted to survive in their environment. Going back to elephants, if a creature from the order proboscidea was the dominant life form on Earth--and the term would be used rather loosely--it would only be because humans never arose. It would be totally unable to rebuild its environment as humans have done.

I don't see your point. The question isn't whether some other form could outcompete humans. The core question under discussion in this thread is whether tool-using sophonts on other planets would be humanoid or more exotic in shape. So arguing about whether they could beat humans is irrelevant, because there wouldn't have been any humans on the planets where they evolved. Evolution would've followed a different path there from the beginning, so there's no reason to assume that anything resembling primates would've emerged in the first place.

Indeed, there's no reason to assume that anything corresponding to elephants, cats, dogs, bats, dinosaurs, birds, or whatnot would've evolved in the first place either. The whole evolutionary tree from the simplest organisms onward would develop independently, and though it would be governed by the same laws of physics and practicality and would therefore have some degree of convergent evolution, it's naive to assume that any specifically terrestrial taxonomic categories would have exact duplicates on other worlds. So it's useless for the purposes of this discussion to argue about whether specific terrestrial forms of life could win an evolutionary competition against each other, because those forms wouldn't exist on other planets. And neither would our own. No matter how many similarities there might be due to convergent evolution, there'd be a wealth of differences too. Consider that the niche filled today by lions was once filled by raptor dinosaurs. They have similar adaptations -- claws, fangs, limbs built for running -- but nobody would mistake one for the other. There is more than one form that can fill a given niche.

My argument is certainly not that aliens would look exactly human. But there would likely be some pretty important commonalities, besides the cognitive abilities, given roughly the same type of planet:

1)DNA basis for its genetic coding. DNA outcompeted other self-replicators on Earth to virtual extinction, there is no reason to believe it would not do so on an alien planet.

I don't agree at all. DNA could've outcompeted other self-replicators by random chance. As you yourself have said, evolution is without design or direction. So it's contradictory to assume that any given evolutionary outcome is the result of immutable destiny. Luck has as much to do with it as anything else. Evolution doesn't select the ideal form for any given adaptation; it just selects the best of the ones that happen to be available.

There's no theoretical limit to how many proteins and organic molecules can exist. There could be thousands of genetic media just as complex and versatile as DNA, but DNA simply happened to be the best one of the genetic media that happened to evolve on Earth. Given the unlimited number of possibilities, it stands to reason that only a finite cross-section would spontaneously evolve on any given planet.

Also, DNA is made up of amino acids, among other things. Life on Earth uses only 20 of the much larger number of amino acids known to exist. We've detected dozens of other amino acids in meteorites and interstellar dust clouds. We don't know why Earthly life favors those 20. It could be because they work better universally, or it could be just because they work better in Earth's conditions, or it could just be the luck of the draw. An alien world might have different amino acids to start with, and so whatever genetic medium it evolved would not be DNA. It might be a double helix, but it wouldn't have the same chemical bases. Again, parallel evolution does not mean identical evolution.

8)Hairlessness and sweat glands are likely, for reasons outlined in previous posts. Inability to regulate body temperature strikes me as somewhat unlikely.

Isn't that making the rather naive assumption that intelligent life would evolve in the same climate we did? What if it evolved in a colder climate? Hair is a way of regulating body temperature. Many animals in cool climates can fluff up their hair to improve insulation, or can change the thickness and color of their hair with the changing seasons, or whatever. That's all heat regulation, it's just heat regulation adapted to a different climate than the one hominids evolved for.

Conversely, in a dry, arid climate, sweating would be a dreadfully bad idea, because it would cost the body too much moisture. Desert animals tend to dissipate body heat by using large membranes as heat radiators. This is why many desert animals have large ears. An alien species might regulate its body heat by evolving retractable fins or "wings" on its body, crests on its head, any of numerous possibilities. Or what about a species evolved in a tropical rainforest-type environment where the air is saturated to begin with? Perspiration would do little good there, because it wouldn't evaporate efficiently.

It may--I reluctantly accept--might not be bipedal.

Going by your premise of "a planet roughly like ours," bipedalism may be relatively common. However, planets like ours may not be that common in one crucial way. Exoplanet studies tell us that terrestrial planets can be as much as 10 times the mass of the Earth, meaning up to 3-4 times the gravity depending on density. It's also believed that tectonic activity is necessary for life, since it helps regulate carbon levels in the atmosphere and maintain a stable climate. But planets smaller than Earth or Venus would probably be incapable of supporting plate tectonics long enough for complex life to evolve, since they'd cool off too quickly. So odds are that the vast majority of inhabited planets would have higher gravity than Earth. Maybe not all the way up to the 4g limit, since planets that large might have too much tectonic activity to be habitable, but certainly over 1g, maybe well into the 2g-plus range. In such high gravities, upright bipedal body plans might not be practical. And evolution on a high-gravity world might select for forms with six, eight, or even more limbs.

 

[FordSVT]

ST:TOS where all of the aliens look exactly like humans?

But one of them is black on the right and white on the left side, and the other one is white on the right and black on the left. THE LEFT!