Oooh I just watched this for the first time last night, I loved it! That bear is damn near perfect monster design. The visuals are fantastic overall, I loved the fungal shapes & plants. I was kinda bugged that they seemed to imply swapping hox genes between species was causing it all though, like that's not how that works. Unless that was supposed to be a guess from the character...but she's supposed to be a biologist? Idk. I still liked the movie.
I took it as someone throwing out a wobbly attempt at a rational explanation to explain something that financially had no rational explanation. She was trying to find some logical stability, but didn't even know where to start.