The Virgin in TV Sci-Fi

I'm hoping to teach a class on conservatism in fiction (a rather short reading list) in the Spring of 2011, so I'm coming up with all sorts of crazy arguments for conservatism, even though I'm far from a conservative. The lecture I'm working on now is called the "Case Against Sex" and it made me think of the treatment of virginity in TV sci-fi. There has been very little sexuality shown on screen, but characters are usually prone to be identified as heterosexual men or women (Captain Jack and company excluded). Explicitly virginal characters are very rare. Until the 1996 Doctor Who movie, and the new series, Doctor who was not, as Terrance Dicks puts it, a "snogger". In other words, he was always suppossed to be above romantic relationships and a little aloof from them. Doctor Who therefore is the model of the viriginal character in science fiction. The other major virgin in sci-fi is Marcus Cole from Babylon 5, where his virginity is seen as a mark of his priest-like Ranger status. The whole priest-Ranger idea is interesting, especially since Marcus's virginity is not tied to a hatred of sex, but simply the fact that he has not found the right woman. This makes his death at the end of season four all the more poignant, because we know he is sacrificing his chance for sexual love, for the woman he has romantic desires for. I think this latter, joyful kind of virginity may be a postive way of depicting singles and virgins in the future, rather than using them as the butt of some cosmic joke.