Trivia: At one point, the opening scene of the clone Alice in the simulated mansion was going to be longer and include re-creations of more moments from the original film. This was to try and confuse audiences and possibly make them believe that somehow they were seeing the wrong film and create a sense of unease. However, it was deemed far too long, and was trimmed down.
Trivia: Director Russel Mulcahy specifically chose to shoot much of the film in daytime, often in direct sunlight in order to both give the film a contrast to the first two, as well as to lend to a bigger feeling of dread and fear, since typically bad things in horror movies happen exclusively at night and day is portrayed as safer.
Trivia: At one point in production, the film was going to be titled "Resident Evil: Afterlife." This was dropped for the title "Resident Evil: Extinction." Interestingly, the original title was then re-used for the fourth film.
Trivia: The creature Dr. Isaacs turns into at the end of the film is modeled after the "Tyrant" creature from the original video-game which served as the end-boss.
Trivia: The scene where a zombie appears to be "domesticated" is a clear reference to the zombie-character "Bub" from George A. Romero's film "Day of the Dead." "Resident Evil: Extinction" also includes several other more subtle references to that film as well.
Trivia: When the man on the flame thrower is attacked by the ravens, he lets out a Wilhelm scream.
Trivia: When Alice's clone stops the lasergrid from killing the real Alice, there is a shot of the computer screen showing the disintegration of Isaacs, Dr. J. This is a reference to Jason Isaacs, who has a history of appearing in Paul W.S. Anderson movies. Anderson produced this movie, so the circle is complete.
Chosen answer: The reason that the cloned alices were put through the tests was their attempt to get a "perfect" clone of her. They knew that Alice was the key to taking back the zombie infestation, so they were trying to get the "perfect" clone. The perfect clone would have all of her memories and reactions, so they put the clones through that testing facility. If she made it out alive, then she was the perfect clone. If she didn't, then it was back to the drawing board.
Nick Bylsma