Whittaker will be the 13th incarnation of the Time Lord, a time-traveling being who regenerates into new forms as he/she explores the universe in a phone-booth-shaped "Tardis" with an Earth companion. She's replacing Peter Capaldi as the twelfth Doctor, who replaced Matt Smith from "The Crown" and David Tennant from "Jessica Jones" before that.
Until now, the Doctor has always regenerated into a white man, leading to growing pressure from some fans for the show to introduce more diversity. This pressure hit a peak during Steven Moffat's stint as showrunner, when his portrayal of other women characters on both "Doctor Who" and "Sherlock" created controversy. Moffat is now stepping down to work on a "Dracula" series with fellow "Doctor Who" writer Mark Gatiss, and will be replaced by Chris Chibnall of "Broadchurch" fame.
Sunday's announcement caused immediate delight from many "Doctor Who" fans - and the beginnings of a pushback from others who see the move as pandering to feminists.
Jodie Whittaker is brilliant, brilliant, bRILLIANT. I am so excited for her Doctor. I am so thrilled about all of this.