Farmer settlers on a distant world are threatened, when after 40 safe years, the native wildlife evolves a taste for human flesh.

I love Alien, Pitch Black and other movies with malevolent extraterrestrial life. But, for the most part, I have to watch them with part of my brain off. Any alien lifeforms that we encounter out there are unlikely to think of us as food. A few critters might try eating a person or two but it’s highly unlikely that any species will decide human beings will be a staple of their diet. Earth life is just not going to be that compatible with the life of other worlds. We’re likely to be unappetizing, indigestible or just plain poisonous.

At first.

The great thing about life is that it evolves. It adapts to changing circumstances. If the native ecology started being slashed and burned and replaced by some other biosphere the native wildlife wouldn’t have a lot of choice. (Not that evolution is a conscious thing. That we know of.) Adapt or die.