There’s enough content in “Biosphere” — enough dialogue, enough story, enough ideas and enough purpose — to sustain a fairly interesting 30-minute movie. But this film never had any business being stretched into a feature, much less one running 106 minutes. At that length, “Biosphere” is soporific and repetitive and puts viewers in the position of always being two steps ahead of it.

Director Mel Eslyn, who co-wrote the screenplay withMark Duplass,seems to know that she has nothing with which to fill the time, so she resorts to loud, choral interludes. Over and over, she will present a conversation between two characters and then cut to showing them focused on rote activities, while a chorus intones above the action. Each time, the chorus sounds like it believes something profound has just taken place. Each time, the chorus is misinformed.

These choral intonations run for 30 seconds to a minute each, so every time Eslyn piles one on, she gets to make her movie incrementally longer. It’s as though she were under the impression that longer means better.

For this reason, it becomes surprising that Duplass, who co-stars oppositeSterling K. Brown(a Stanford University grad who can be seen in the much better comedy-drama “Honk for Jesus. Save Your Soul”), should get involved in such a project, even to the extent of producing it with his brother, Jay Duplass. The Duplass brothers’ previous films (“The Puffy Chair,” “Baghead,” “Cyrus”) are models of concision, without any wasted moments, much less wasted scenes. “Biosphere” is almost entirely a waste.

The story is about two guys living in a geodesic dome with no possibility of escape. The experience is something like the pandemic lockdown, only worse — it’s forever. Duplass plays Billy, a former Republican president of the United States, whose distinction seems to be that he ruined the world. Presumably, he blew it up. Brown plays Ray, his oldest friend and former adviser, who is also a scientist.

In this way, “Biosphere” is the usual buddy comedy, where there’s a funny guy (Duplass) and a serious guy, and they spend a lot of time bantering. But there are several crucial exceptions: Buddy comedies are usually funny, at least a little, and in buddy comedies, the lead characters usually get to interact with other people. In “Biosphere,” the laughs are nonexistent, and the two guys can’t interact with others because they’re the last two people on Earth.

Duplass饰演比利的兄弟much intelligence who says something interesting even less often than he washes his hair. He’s not someone you’d want to be stuck with for the rest of time, which throws sympathy toward Ray, who is grounded and reserved in Brown’s portrayal.

Ultimately, “Biosphere” deals in issues of gender — the details will not be revealed here. But to watch the movie is to get the impression that Eslyn and Duplass really thought they had a big fish on the line. Did they really believe that the mere raising of the gender issue would be their Get Out of Jail Free card, allowing them not to craft a decent story or write sharp dialogue? Otherwise, it’s hard to explain how the screenwriters thought they could just show two guys on a couch, calling each other “dude,” and assume audiences would be interested.

Duplass and Brown are likable actors, and that likability, established in other, better movies, carries into “Biosphere” and buys it a portion of goodwill. But the last morsel of that portion is consumed long before the movie’s midway point.

Reach Mick LaSalle: mlasalle@sfchronicle.com