My first post was about how zombies in pop culture have metaphoric meaning. I think perhaps other common science fiction creatures also convey meaning in contemporary culture. As an example, I think aliens in Western film represent societal unease about issues of immigration and cultural exchange.

On the positive end of the spectrum are movies like Contact and Close Encounters, where the emphasis is on what we can learn from making new contacts with intelligent life. Men in Black seems to be a metaphor for the American melting pot, where aliens/immigrants must learn to become assimilated and productive members of American society.

On the negative side are movies like Avatar and District 9 deal with issues of racism and the destruction of indigenous ways of life. Shoot-em-up movies like Independence Day and Mars Attacks promote a very, um, Bush-esque philosophy for how American patriots should deal with resistant foreign cultures. Shock and awe!

There are some movies that do not quite fit into this model, but are related. The Alien series and The Thing symbolize the destruction caused by invasive alien species, much like cane toads in Australia. In the Predator series, highly advanced aliens come to earth on hunting trips wreaking havoc for the humans they encounter, much the way sometimes self entitled Western tourists have been criticized as doing when they visit Third World Countries.

One could continue with other science fiction creatures, such as vampires and werewolves that are popular in the cinema right now are.