“Why do you have to be married? It doesn’t mean anything anymore,” Phil Miller (Will Forte) tells Carol (Kristen Schaal) over dinner on “The Last Man on Earth,” which premiered on Fox on Sunday night. “It means something to me,” Carol protests. They might have been young characters in almost any romantic comedy or sitcom, bickering over where their relationship was going.

But there was a twist to their conversation: Phil and Carol are the last apparent survivors of a virus that wiped out the rest of Earth’s population. They’ve both reluctantly decided they have an obligation to procreate to keep the human race alive. And so even though she and Phil are totally different people, and not in an opposites-attract way, their coming-together is inevitable. “The Last Man On Earth” may be a riff on the post-apocalypse, but it’s also a savage satire of the dominant romantic comedy story of the last decade, in which a schlub who takes small steps towards maturity is rewarded with a smoking-hot woman.

The movie that best established this pattern was “Knocked Up,” Judd Apatow’s 2007 dramedy about Ben, a stoner living off the settlement of a lawsuit (Seth Rogen) who gets gorgeous television journalist Alison (Katherine Heigl) pregnant. “Knocked Up” never bothers to come up with a reason Alison might want to keep the baby, much less pursue a relationship with Ben, given the ample support system that surrounds her.

“Forgetting Sarah Marshall,” which followed the next year, at least had the decency to explain why Rachel (Mila Kunis), a manager at the hotel where Peter (Jason Segel) comes to recover from a breakup with his actress girlfriend (Kristen Bell) and to reckon with the lassitude that has overcome his life, ends up with Peter. Rachel is a college dropout with a history of bad relationships; Peter presents Rachel with as much an opportunity to remake her life as the other way around. But even as variations did better or worse with the formula, there was something exhausting about the basic imbalance in an equation where there was nothing a man could do to drive a woman away, because said women apparently had no other options at all.

“The Last Man On Earth” eliminates that perplexing hole at the center of so many romantic comedies: Phil and Carol have searched the whole country, and both of them truly have no other options, either for romantic partnership or even simple companionship. “30 Rock” once featured a story where Liz Lemon (Tina Fey) faced the prospect of a “settling soulmate,” a man (Michael Sheen) she didn’t much like but roughly matched in attractiveness, professional accomplishment and relative weirdness. “The Last Man on Earth” is like that, but without the optimism. Phil and Carol can’t take Liz’s example and recommit to the New York dating scene in a world where New York only exists as a bunch of empty buildings.

The show also doubles down on the idea that Phil and Carol’s differences aren’t cosmetic or cute — they’re deep-seated and, sometimes, truly off-putting.

Phil starts his post-apocalypse experience responsibly, searching the rest of the country for other living people, and directing any survivors to find him in Tucson. But he quickly descends into an orgy of boyish consumption, taking over a McMansion, and stocking it with pilfered dinosaur skulls, fine art, Oscars and Heisman trophies and looted wine. Phil sleeps under Emanuel Gottlieb Leutze’s canvas of George Washington crossing the Delaware River and sleeps in Hugh Hefner’s actual pajamas. And as despair sets in, he begins to live in his actual filth, turning a swimming pool into a toilet and lounging in a wading pool full of tequila and rimmed with salt. Phil isn’t just arrested, he’s fully regressed.

Carol is appropriately grossed out by Phil, but she’s got some irritating tics of her own. She’s a grammar freak who insists Phil stop at stop signs and park in actual parking spots, and is disgusted when she sinks to his level of personal hygiene when she can’t find a way to rig running water. If Carol is annoying, though, she at least hasn’t given up as thoroughly as Phil has. And she does inspire him not just to return to basic levels of human functionality, but to try to figure out an irrigation system for a garden.

In romantic comedy’s, a man’s embrace of maturity is usually the work of a jauntily-scored montage, and the happy couple resolve their major differences by the final credits. But a real marriage, in which couples have to reconcile themselves to each others’ flaws and alter their characters, is not the work of 90 minutes and three acts. “The Last Man On Earth” has the format and time to actually explore what it would be like for Phil and Carol to make the accommodations that will help them stave off loneliness. Whether we really want to watch them make that sort of un-glamorous compromise — and clean up Phil’s disgusting pool — will be the show’s real test.