Representation – there’s a slideshare on this blog to look at –
But think – are these people stereotypes (the screaming, attractive, vulnerable female, the evil scientist etc) or is there more than meets the eye? To give an example, Dr Susan Tyler in Mimic manages to be both. She is the counter-stereotype in that she is the intelligent , attractive, young female scientist who stops the plague, but she is also used as the victim in some scenes (the lonely traveller on the subway). At the end, however she is the one who defeats the male head of the Judas insects. The fact it is male, makes her even more of a countertype.
Look at Ripley in Alien. She is extremely attractive and at the end, parades around in underwear to show off her figure, yet she is the lone survivor of the crew. She outlasts all the macho men and she is the one who uses her ingenuity to defeat the alien and send it hurtling into space.
The soldiers and scientists in The Thing From Another World seem like a typical group of American macho men who will defeat the stereotypical evil alien who has not motive but to destroy, but they are an inclusive group, including women who take part in the final destruction of the alien. Even the scientist, who is a stereotype, though more gullible than evil, is welcomed back in the fold after the alien is defeated when he is referred as having sustained wounds in the fight.
What about the casting of Will Smith in several science-fiction films. Once upon a time, this kind of role would have been given to white actors. The two previous versions of I Am Legend featured white actors in that role. He has, along with Tom Cruise, George Clooney and Matt Damon, become an actor associated with the genre.