I didn't know that there was a debate surrounding the general crappiness of alien diversity in Star Trek. Plastic nose/brow piece does not equal parallel evolution. With the possible exception of Tin Man, that rock eating creature from TOS and the Crystal Entity, all the aliens portrayed in Star Trek are fairly lame. As a matter of fact, most aliens, no matter who portrays them seem very unlikely. That's probably because no matter what a human imagines, it will still be influenced by human bias. You don't have to have two legs and two arms to be intelligent.