But even if life on another planet has the same molecular chemistry as life here, there is no reason to expect it to resemble familiar organisms. Consider the enormous diversity of living things on Earth, all of which share the same planet and an identical molecular biology. Those other beasts and vegetables are probably radically different from any organism we know here.
There may be some convergent evolution because there may be only one best solution to a certainenvironmental problem - something like two eyes, for example, for binocular vision at opticalfrequencies. But in general the random character of the evolutionary process should create extraterrestrial creatures very different from any that we know.
I cannot tell you what an extraterrestrial being would look like. I am terribly limited by
the fact that I know only one kind of life, life on Earth. Some people - science fiction writers and artists, for instance - have speculated on what other beings might be like. I am skeptical about most of those extraterrestrial visions. They seem to me to rely too much on forms of life we already know. Any given organism is the way it is because of a long series of individually unlikely steps. I do not think life anywhere else would look very much like a reptile, or an insect or a human - even with such minor cosmetic adjustments as green skin, pointy ears and antennae.
But if you pressed me, I could try to imagine something rather different
hyeah:...
The Prequel Pitch Black was Good but it was not Horror !