In the classic version of the television series, Dr. Who, the diversity of sex among the characters should hardly be considered diversity at all. Women typically only have a role or two for every season, and the roles they are given are typically “female roles”. Please note this is not meant to be a feminist piece of any kind. The roles females played in Classic Who episodes are something that stuck on to me in particular, so I only wish to announce some of the observations I made.
Now, when I say “female roles”, I mean roles that fit a stereotypical mold of how women are commonly portrayed in television and cinema. For example, in The Green Death, the female companion, Jo, starts the season off as a somewhat strong female presence; however, as the season continues, she becomes more and more dependent on the Doctor and others around for saving and emotional consolation. This type of role is fairly common is the series, and it makes sense in a way since the Doctor is typically going to be saving the people around him which would include his companions.
As a general trend, the female companions seemed to get gradually more useful towards the latter seasons of Classic Who, which makes me wonder if the producers were becoming more aware of their portrayal of women and thus started making a concerted effort to give the females a more prominent presence. An example of a stronger female companion comes from The Curse of Fenric season where the female, Ace, is a particularly clever woman who even goes as far as saving the Doctor’s life by uncovering a hidden bomb.
I believe the writers of the show made an effort to give women an equal chance to be a heroic figure in some of the Classic Who episodes. Perhaps someday, the writers will go as far as making the Doctor a female. Obviously, there are some logistics that would have to play into that scenario but that is a discussion for another day.