1. I don't have to 'believe in evolution'. It is a proven, scientific fact(despite the frequent and erroneous argument that it is 'only a theory').
It is only a theory only a Scientific Theory which means that it has passed a certain rigorous set of tests that say that it is accurate enough to use in the development of further theories. This is many orders of magnitude more rigorous than any religious belief (say 10^10 orders of magnitude).
P.S. I am mostly posting this to not use my mod points for evil.
"Starship infantry" would have been better, although given the book's purpose as pro-military propaganda it lacks that romantic haze required to blur away the pointless death and destruction such troops have always created when deployed outside their own borders.
I've never been quite clear as to whether it was pro-military propaganda or straight sarcasm. In reading many of Heinlein's other works I eventually started to believe that it might indeed be the latter. Either way Heinlein must have been a very interesting person (read crazy) possibly in a good way.