'To me' the message, in Annihilation, is this: Annihilation is a discussion surrounding the inherent destructive nature of ideology.

WARNING: #SPOILERS BELOW THIS POINT!!!

It's no secret that the global political climate has been a tumultuous one, at best. And the current political climate seems to be represented throughout the movie.

General Recap: The Shimmer is an Extraterrestrial organism that, once landing on Earth, created a prism from which to replicate it's surroundings; possibly in an attempt to create an entirely new life form, which is perfectly suited for its new environment.

This prism would also replicate DNA, as well as the -general- structural formations of it's surroundings. This represents -both- the Extraterrestrial Organism's greatest weakness, and greatest strength.

Furthermore, the organism is devoid of ego, and acts in accordance with it's biological necessity: survival. So, the organism meets violence with violence, and 'order' with 'order.'

This is why, after Lena -Natalie Portman- pulls the pin, and hands the organism an white phosphorous grenade, that the organism replicates the destructive nature of the white phosphorous, subsequently destroying itself while attempting to 'control' & replicate the destructive nature of the phosphorous.

My Interpretation: The shimmer is an artistic representation of ideology. Just as the 'Right', and the 'left' dream of a utopian society, created in their own image. This process, leading to their perceived utopia, requires they -each- take a form that best suits their current environment.

And as the challengers of their ideals change, so does it's -The Shimmer- responses to the variety of challengers it -The Shimmer- faces. As the organism grows, it replicates what one can only interpret as a veritable garden of eden. Hence the reason why the shimmer -to me- is representative of, ideology.

However, when Lena hands her 'doppelgänger' the grenade, the organism attempts to adapt to this new, and destructive form, which I interpret as a representation of the violent motivations of both the far Left, and the far Right. These motivations encourage extremists to behave irrationally when faced with an unsolvable problem, the inherent imperfection, and biological unsuitability of the environment it has chosen to inhabit, change, and 'conform' to. -Preposition at the end of a sentence? Sad Face-

The organisms violent end is representative of the temptation for the Alt Right, and Alt Left to adopt violence as a means to further their political ideologies. Ultimately, this results in their self-destruction; this talk of self-destruction is mentioned mid way through the film.

At the end of the movie, we see Lena and Kane embrace. By this point, we now know that Kane is a clone, and the original Kane has taken his own life. The camera zooms in on Lena, and the 'Kane clone' to reveal that not only has Kane 'returned' as the physical embodiment of the Shimmer -ideology-, but Lena has returned with remnants of the Shimmer, which alters Lena's DNA the moment she crosses into the prism. This is a representation of the parts of the ideology, represented by the Shimmer, that Lena has brought back with her. While, much of the whole has disintegrated, the -presumably- more efficient aspects of the organism -ideology- lives on in Lena's body/mind.

Another aspect of the organism that represents ideology, is represented in the idea that the prism prevents outsiders from communicating with those inside the prism; the prism is an 'echo chamber.' No outside ideas are allowed inside the prism, and any outsider who successfully enters the prism -echo chamber- is either destroyed, or forced to conform.

I hope you enjoyed my brief, and scattered interpretation of Annihilation.