Good acting but flawed movie

Rating: Null/10 (5 November 2018)

Annihilation (2018)
Ir's a scifi horror. The problem is that it's difficult to translate the first person account in a novel to the third person narrative captured on camera. There's a great deal of ambiguity about motive and responses.
In general, the movie's premise mirrors that of the book. An alien organism arrives on earth, and begins to transform the area into an alien biosphere. Plants, fungi and animals are transformed as their DNA is altered.
The threat is mentioned but not fully articulated in the movie. The alien biosphere is expanding rapidly and all existing life is threatened.
In the movie, the plot about the expedition is very different from the book.
Several military teams have entered the biosphere, but none have returned. Until the protagonist's husband mysteriously shows up alone on her doorstep.
The protagonist (a biologist) joins an all-woman academic team to explore the strange new world. Apparently, radio and GPS is disabled. So, the team has no information from the previous expeditions. And, they don't realize that they have been in the biosphere for weeks.
We don't know much about the team members, only snippets from the gossip between the ladies.
They are horrified by the discovery of strange animals and flora as they follow in the footsteps of the previous expedition. Eventually, some are killed. Some mutate into plants.
Realizing that they are changing, the team leader rushes to the core of the alien entity at the lighthouse, "while I'm still human". Why? Presumably because she hopes to merge with the alien core and mutate it. Her motive is not explicitly explained.
IMO, the most significant discovery was that of the doppelgangers. The alien entity is creating identical copies of humans. Why? Presumably to understand/communicate/compromise with the existing biosphere.
The story ends in an unsatisfactory manner. The protagonist manages to ignite her doppelganger and the entire alien biosphere collapses!
With patience, the viewer can follow the growing horror of the humans. But, the screenwriter and director should also include the bigger picture in order to craft a better ending.
In conclusion, it's a thought provoking narrative. But, lacks balance between emotive and logic.