Star Trek tends to take elements of human culture, over –exaggerate them and then make it the principal cultural trait of an alien race. So with Trek, it’s not just about exploring space, it’s also about exploring ourselves on another level.
Trek aliens are usually of the ‘bumpy forehead’ variety largely down to being a weekly TV show that needs a cheap means of showing who isn’t human. In fact, the most interesting aliens in all SF are the ones who look human but aren’t.
I loved Chris Eccleston’s comeback to Rose in the first Dr Who story when she quizzed him about the fact that if he’s an alien, how come he sounds like he’s from ‘the North’.
‘Lots of planets have a north’ was the witty reply
. Very true!.
I also believe that the Doctor once said that humans look like Timelords and not the other way around. He may have gone on to say that although he looks human, he’s ‘not the monkey’s uncle’.