by Subsplot » Wed Apr 29, 2009 5:54 pm
There are logical reasons why some alien life might bare a striking similarity to us. Evolution tends to throw up similar answers to similar problems. Don't believe me, well the eyes of squids and octopuses are almost the same as a humans yet we're light years apart in terms of genetics and evolution. Therefore its reasonable to assume that other bipedal, upright, two armed life forms have evolved as well, it's even reasonable to assume that all carbon life that's emerged on planets similar to ours will follow patterns we'll recognize. That doesn't mean their DNA will be compatible with earths, or that it will even have the same base pairs. You can even assume that recognizable patterns could evolve in environments completely alien to ours. Remember that squid, well give it some sort of light than its native atmosphere flotation organ and the ability to quickly adapt to different pressures and you have a life form that suits a gas giant quite well. It even has dexterous tentacles for tool manipulation, doesn't need opposable thumbs if it's intelligent enough.
All that said that's only some life, given the amount of different types of completely alien environments out there and the theory that life could build itself around a silicon or nitrogen base and might not even need liquid water or oxygen it's also is reasonable to assume that some alien life is nothing like anything we've ever encountered before. I suspect the spectrum of highly evolved intelligent life forms runs from humanoid right through to bug eyed tentacled monsters. (If you want a good read about a believable and genuinely horrific alien invasion read 'The Kraken Wakes' by John Christopher, I've always imagined the alien race in that of being squid like.)
And here's one last thought for you. Only predators evolve with forward pointing eye's capable of sharp focus, with meat cutting teeth and long digits that ended in hardened masses and only predators have learned to move fast by tipping their center of gravity forwards and using momentum to keep them going (and if you think moneys and apes aren't predatory one of my friends looks after a silver back your welcome to meet). So maybe just maybe those sentient species out there are interested in us because they've seen our kind before, and they know what sort of havoc we can wreck, especially if we've just learnt to split the atom. It's pretty reasonable to assume that they're not the monster's, we are especially if you take into account our behavior.