Starring Bryce Dallas Howard and Chris Pratt. Rated PG. Now playing

Don’t people in science-fiction movies ever watch science-fiction movies?

If you’re in Starfleet, do not accept a red shirt. If you’re fighting aliens (or dinosaurs, as in this movie), do not wear a heartbeat monitor the main function of which is to inform the audience when you have been flatlined by some fast-moving scaly thing. And if you’re a mad scientist, do not make monsters!

Especially, one should refrain from creating an enhanced version of a T. Rex that is smarter, tougher, and more violent, with chameleonlike camouflage. What possible good can come of that?

According to Claire (Bryce Dallas Howard), park manager of the new Jurassic World, the answer is a rise in stock value. For the idealistic owner (Irrfan Khan), the dream is to create living history. For his security chief (Vincent D’Onofrio), it is an opportunity to build a weaponized dinosaur.

That dab of cynicism is about all the social commentary that Jurassic World has to offer. It also skimps on the character development. Claire is an uptight corporate minion in heels who must learn to shoot guns and to love a manly man, and look! It’s Chris “Star-Lord” Pratt as raptor expert Owen, offering both guns and his kissable lips! Screaming, running, and heteronormative bonding ensue.

So it’s silly and not too ambitious. Jurassic World is also fun and eye-catching, which is to say that it fulfills its primary mission.

Director Colin Trevorrow, whose previous feature was the charming science-fiction romance Safety Not Guaranteed (an apt title for his film work), paces the movie patiently. He builds suspense, establishes the geography, defines the capabilities of these high-tech resurrections, and sells the fear of nasty creatures described as “bigger, louder, more teeth” by one character and simply as “cool” by another.

If there is a major disappointment, it is that the movie functions largely as a reboot of the franchise, rather than its logical evolution. The “world” aspect of Jurassic World just isn’t here. Then again, while safety is not guaranteed, a sequel is bluntly foreshadowed.