After what has seemed to many an interminable wait, the BBC revealed on Sunday that Doctor Who is getting its first female Doctor. And, to put it mildly, it's about time.

The announcement that Jodie Whittaker, who appeared on all three seasons of the acclaimed crime drama Broadchurch under incoming Doctor Who showrunner Chris Chibnall, came in a specially shot minute-long trailer broadcast after the BBC's coverage of the 2017 Wimbledon Men's Singles' final, and instantly became a breaking-news item on BBC News and beyond.

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The trailer shows a hooded figure, the new Doctor, walking through a verdant forest. As the Doctor walks, we can hear the distinctive sound of the TARDIS becoming louder and louder until a key appears in the person's hand, and then the Doctor pulls down her hood to reveal her face. Looking directly at the audience, she gives a slight smile as she recognizes her old blue box, and takes her first steps toward her first big adventure.

Of course, Whittaker is no stranger to sci-fi; she starred opposite John Boyega (in his film debut) in 2011 in Joe Cornish's Attack the Block. If you haven't watched that film yet, seriously, fix that now.

It's a bit of an understatement to say it's taken a while to get to this point but, as the Doctor has said himself, back when he was a man, "the moment has been prepared for." Long prepared for, as it turns out. Audiences were actually introduced to their first female Gallifreyan in the show's first episode. Described as "An Unearthly Child" in the title, Carole Ann Ford's Susan Foreman debuted in 1963 as the Doctor's granddaughter, but the show during its second season.

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Throughout the course of its classic 1963-1989 run, Doctor Who featured a variety of "Time Ladies," from assistant Romanadvoratrelundar (Romana for short), played across two incarnations by Mary Tamm and Lalla Ward, to adversary The Rani (Kate O'Mara), and various authority figures such as Chancellors Thalia and Flavia (Elspeth Gray and Dinah Sheridan, respectively) and the Inquisitor, played by Lynda Bellingham. But none of those were ever depicted as having changed gender.

Jodie Whittaker as the Thirteenth Doctor

The first time such a swap was even suggested appears to have occurred in 1981, when the outgoing Fourth Doctor Tom Baker was asked by a journalist what sort of man his successor would be. Apparently the actor replied, seemingly at least part in jest, "Well, you’re making an assumption that it’s going to be a man." The comment provoked some mirth at the time, followed by a lot of fan speculation over the ensuing years, something encouraged by the show's then-producer John Nathan-Turner, who had a keen instinct for doing whatever he could to keep the show in the public eye. But no serious attempt was made to actually cast a female Doctor until the Steven Moffat-penned four-part Comic Relief sketch The Curse of Fatal Death in 1999.

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Produced at a time when the prospect of a new regular Doctor Who series on TV was seen as the stuff of a madman's dreams, the charity episode took great joy in burning through the Doctor's regenerations at a lightening pace to provide fans with some screen time with a veritable wish list of actors playing the rogue Time Lord. Intriguingly, the Thirteenth Doctor in the story was played by Absolutely Fabulous star Joanna Lumley, so it would seem that Moffat's comedy sketch predicted not just Doctor Who's eventual return to the small screen, but also the advent of a female Doctor some 18 years ahead of time.

Joanna Lumley as the Doctor in 1999's The Curse of Fatal Death

In-canon, the show took somewhat longer to take the first baby steps necessary to unambiguously state that Time Lords could, and did, change gender when regenerating. The first of these came in 2011 in Neil Gaiman's "The Doctor's Wife," in which the Eleventh Doctor (Matt Smith) revealed that his old friend The Corsair "Didn't feel like himself unless he had a tattoo, or herself a couple of times. Oooh, she was a bad girl."

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This revelation just hung in the air until the casting of the brilliant Michelle Gomez as Missy, the first female incarnation of the Doctor's longstanding Time Lord foe The Master, in the 2014 two-parter "Dark Water/Death in Heaven." Gomez gave Missy/The Master a demented mercurial malevolence that kept audiences, and everyone else, on their toes. Like an evil Mary Poppins, you really didn't know what she was going to say next, other than it would likely be spiteful, mean or needlessly cruel. Gomez has apparently said she won't be returning to Doctor Who under its new showrunner, and the Season 10 finale did seem to give her character a distinct sense of an ending. But I'm still hoping against hope she will return again at some point, just like past Master John Simm.

Michelle Gomez as Missy on Doctor Who

While Missy demonstrated the existence of gender-changing regenerations – regenderations, if you will – the first we actually got to see on screen occurred in the Season 9 finale "Hell Bent," with The General, played here and in "The Day of the Doctor" by white male actor Ken Bones. Shot by the Doctor, Bones' General regenerates into actress T'Nia Miller, who's both female and a person of color. Even at the time, but more so now in retrospect, this feels like the moment that most clearly demonstrates that, despite having been cast exclusively to be played by white male actors in the past, the Doctor would not be pale and male forever. Indeed, looking back, the Season 10 finale almost seems to be screaming that the next Doctor would be a woman. Simm's Master even asks, "Is the future going to be all girl?" to which the Doctor replies, almost winking at the audience, “We can only hope."

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Perhaps the only thing more inevitable than a female Doctor at this point is that some self-proclaimed fans are expressing their dismay that the character could be portrayed anyone other than a white male actor with a British accent. But such mistaken beliefs miss the most important element of the show's continued success over the years: its ability to change. That's the very thing that has made Doctor Who the longest-running sci-fi show on television. Change has allowed it to recast its main actor, to switch from black-and-white to color, from 30-minute serials to 45-minute (mostly) self-contained episodes and from a show that was quietly not renewed back in 1989 to one that was reborn in 2005 and is still going strong to this day. Indeed, it's been reported that under Chibnall's tenure as showrunner, Doctor Who has already been green-lit for at least three more seasons.

T'Nia Miller as The General on Doctor Who

Yet, amid all the celebration, it's entirely understandable that many fans will also feel a level of disappointment that we have not yet had a person of color cast as the Doctor. This concern is just as valid as it is true, but I remain convinced that we will have an actor of color in the role in the future and, just as with that casting of Whittaker, when that does happen, it will still be long overdue.

As the Sixth Doctor put it in the closing moments of The Caves of Androzani, what's happening is "Change, my dear, and it seems not a moment too soon." This is a genuinely exciting moment for Doctor Who and its fans. Even before the first episode of his tenure has been filmed, Chibnall has already reinvented the show, again. I can't wait to see Whittaker in action, but wait I shall have to. It really is all about time.