Sometimes it's tempting to rely on movie adaptations to get a feel for a book if you're crunched for time. Say you're walking into a reading quiz, or you need to write a last-minute essay, you might watch the movie to get a general idea of the plot and important themes of a text. You might be able to get away with that for something like The Great Gatsby, where the director is generally faithful to the source material, but for Alex Garland's movie adaptation of Annihilation, it would be like you were talking about a totally different story, because you would be. Garland, a novelist and screenwriter himself, is more interested in telling a separate story inspired by the world of Jeff VanderMeer rather than retelling Jeff VanderMeer's story in a different medium. That being said, here are some of the major differences between Garland's 2018 film and VanderMeer's novel, published four years prior to the film's release.
First of all, there is no "narrator" in the film, which you often find in movie adaptations of novels. Since the best novels' stories necessitate the form of a novel, filmmakers have a hard time losing the convention of a narrator because it would come at the cost of essential plot points and explication that sets the stage for the main drama of the piece. If they were required to show all of that explication, they might be stuck with an eight-hour-long movie. So, instead, they often just include a voice-over. Some film purists might claim that a voice over is "cheating," and that film should be able to communicate purely in scenes; when film adaptations of novels include a voice-over, its often a testament to their resistance to adaptation. But, as previously mentioned, Garland is telling a fundamentally different story from VanderMeer. For one thing, the explorers all have names, so if you refer to the biologist as "Lena" while talking about the book, it's a dead giveaway that you've just seen the movie. But aside from the excision of the biologist's backstory, the biggest difference between the movie and the novel, on a fundamental level, is their primary thematic concerns, which distinguish themselves in the way they each conclude.
While the book focuses on the biologist's obsession and explains the reappearance of explorers in the "regular" world as dopplegangers assembled by organisms in Area X, the movie is far more concerned with the notion of escape. The movie concludes with Lena (the biologist) being reunited with her husband, who was a member of the previous expedition, in a medical facility run by Southern Reach. The last shot of the movie closes in on Lena's eyeball, where you can see that she has been biologically altered by Area X, just like her husband. It's unclear whether it is Lena and her husband in the room, or whether these are two totally different beings that merely look like Lena and her husband. While the novel informs the reader about the distinction between the "original" humans and their reconstructions, the film leaves it as an open question. Garland takes a very similar approach to the theme of escape in his previous film Ex Machina.
