After much adversity, Caesar — the leader of the simian takeover of Earth — must admit a hard truth. His bickering, backstabbing ape brethren are much more like humans than they’d care to admit.

Ouch. Caesar’s grunted insight comes as no surprise as we’re watching “Dawn of the Planet of the Apes”: the human population is not behaving admirably in the wake of the health apocalypse that killed off most of the population.

In the time since the collapse, the apes have only gotten stronger. As you no doubt recall from “Rise of the Planet of the Apes,” the successful 2011 reboot of a dormant franchise, the renegade primates got new brain power from an experimental drug and are just beginning to talk.

The best thing about “Dawn” is the opening 20 minutes or so, spent entirely with non-humans. They build, they plan and they speak to each other in sign language (translated for us with subtitles). It’s not “2001: A Space Odyssey,” but it’s not bad, either.

Caesar is once again “played” by Andy Serkis, whose performance has been digitally transformed into a full-fledged monkey turn. He’s very good; Caesar is one of the more expressive performances of this summer’s blockbusters, which maybe isn’t saying all that much.

The apes are up in the Muir Woods outside San Francisco. In the crumbling city, a population of surviving humans is chaotically trying to keep it together.

If director Matt Reeves (“Cloverfield”) meant to make the people colorless by comparison with the apes, he certainly has succeeded. Jason Clarke and Keri Russell don’t register much, and Gary Oldman is reduced to looking at old family photos and weeping. We don’t know anything else about him.

Some very boring plotting about a nearby dam eventually gives way to bigger action, as wise Caesar finds his authority challenged by a warmongering rival called Koba (Toby Kebbell). Which proves there’s a bad banana in every bunch.

“Dawn” gets the spectacle going in the late battle (there’s one wild shot from the top of a tank as it spins around to show hundreds of primates overrunning the city). But the story is so thin it develops very little tension along the way.

Even odder, the film is really corny. There are far too many scenes of apes and humans clasping hands and hugging monkey babies. If Charlton Heston’s cynical character from the original 1968 “Planet of the Apes” saw this, he’d blush with embarrassment.

“Dawn of the Planet of the Apes” (2 stars)

A dull sequel to 2011’s “Rise,” this one charts the progress of the brainy apes and their wise leader Caesar (Andy Serkis) as a group of colorless humans try to survive in the post-apocalypse. The apes are very expressive, but the story isn’t compelling this time.

Rating: PG-13, for violence

Opening: Friday at Alderwood Mall, Cinebarre Mountlake Terrace, Everett Stadium, Galaxy Monroe, Marysville, Stanwood Cinemas, Pacific Place, Thornton Place Stadium, Woodinville, Blue Fox Drive-In, Cascade Mall and Oak Harbor Place.