The Evolution of Sigourney Weaver
People change through ages, but the evolution of Sigourney Weaver wasn't the ordinary change. Her role of Ripley in Alien triology changed her more radically than the life itself could ever do. Here's the path of her evolution from the sweet girl in Alien (1979) to Rambo-like girl in Alien Resurrection (1997).
Alien Resurrection 1997
Can you see the difference? This kind of evolution of Sigourney Weaver is something completely unique in filmorgaphy, since no other character has changed that much in movie sequels.