I’ve always found it fascinating just how much commonality there is between us and many other life forms on earth. The explanation is quite simple: certain biological features are the most suited to the world that we live in and thus give the highest chance of survival and procreation. Still even with that fact in mind I still marvel at how much in common we have with even the most bizarre creatures and it gets even more intriguing when you go down to the DNA level. It’s been well known for a long time that we’re genetically very similar to primates to the tune of something like 95%.
One of my favorite astrophysicists (yes I have several) Neil DeGrasse Tyson made a fascinating point about that small genetic difference (skip to 7:35, although the first point is amazing too):http://www.youtube.com/watch?v=rDRXn96HrtY
All we are, all the stuff that differentiates us from the great apes is contained in that small difference of DNA. The idea then that another form of intelligent life could be that different from us again really is fascinatingly disturbing as from their point of view we’d be little above cattle to them. You’d hope though that past a certain level of intelligence you’d have some respect for any form of life (like many humans do) but our history has shown how even intelligent species can regard their own as beneath them.
Now if you’ll excuse me I’ll just go and work my way through this existential crisis I’m having.