The carcasses of dead television shows line 2014 like roadkill. More than 70 shows were canceled during the year, according to websites that track such things. Some had enjoyed long runs and had simply reached the point of diminishing viewership that practically all series encounter eventually. Others lasted a few episodes.

If nothing else, this collection of corpses proves that television viewers are a fickle lot. Sure, there are plenty of bad shows and lousy actors in 2014’s dustbin, but there are good ones, too.

So what can we learn from the carnage? Here are some lessons from the 2014 Cancellation Calendar.

January — The lesson: Nostalgia about nostalgia has limits. It’s been 10 years since HBO’s “Sex and the City” ended, so fans now look back on it with wistful reverie. Perhaps CW was trying to capitalize on that with its 2013 series “The Carrie Diaries,” a prequel about the teenage years of Carrie Bradshaw (Sarah Jessica Parker’s character, played in “Diaries” by AnnaSophia Robb). Would original fans watch with their tween daughters? The series ended Jan. 31.

February — The lesson: Two X’s is one X too many. In 2013, FX introduced a fearless, provocative series called “Legit” starring Jim Jefferies, the Australian comedian, and featuring a memorable performance by DJ Qualls as his friend Billy, who had muscular dystrophy. For the second season, which began Feb. 26, it was moved to the new and terribly named FXX, an offshoot channel. Apparently viewers didn’t follow, and the show died.

March — The lesson: People still prefer their TV cops to be people. One of the more intriguing shows introduced by Fox in the fall of 2013 was “Almost Human,” a futuristic series in which a police officer was teamed with an android partner (Michael Ealy). It didn’t get a second season; the final episode was aired March 3.

April — The lesson: Television viewers hate extraterrestrials. Those who gave it a chance knew that “The Neighbors,” an ABC comedy (with Simon Templeman) about a community populated by aliens and one human family was one of the most original sitcoms in a long while. The show’s second season ended in April, and there wasn’t a third.

May — The lesson: What was funny in 1981 isn’t necessarily funny now. The 1981 movie “Stripes,” about misfit military men played by, among others in a memorable cast, Bill Murray, Harold Ramis and John Candy, was darned funny. “Enlisted,” a Fox sitcom introduced in January starring Geoff Stults, somehow wasn’t. In early May, the network announced that the show was being canceled.

June — The lesson: Success doesn’t guarantee success. J.J. Abrams has had a hand in some long-running shows: “Lost,” “Alias,” “Fringe.” But 2014 was not his best year. Three of his shows were canceled, including “Almost Human” and the NBC series “Revolution.” The third, NBC’s “Believe,” was about a girl with supernatural powers on the run from nefarious people. The last episode was broadcast in June.

July — The lesson: Know your target. “Seed,” a comedy about a bartender (Adam Korson) who encounters assorted children born thanks to his sperm donations, ran for two moderately amusing seasons in Canada. But when CW tried to import the show as a summer offering, the results weren’t as good: It had its premiere in mid-July and was canceled before the month was out.

August — The lesson: Pirates may be over. Johnny Depp made pirating cool in the first few “Pirates of the Caribbean” movies, but more recent installments have not had quite as much mojo. Yet NBC tried to catch the fading trend with “Crossbones,” starring John Malkovich as Blackbeard. The network burned off the final episodes in early August.

September — The lesson: TV stars + Twitter = trouble. Maybe “CeeLo Green’s The Good Life” was just a dumb reality show that deserved to be canceled after two months. The show was killed in early September after one season.

October — The lesson: Television viewers hate rogue doctors. A 2012 Fox series called “The Mob Doctor” about a physician who treated mobsters didn’t catch on, and neither did “Rush,” a summer offering on USA about a doctor (Tom Ellis) with a shadowy career as a fixer, making house calls for well-heeled clients who had, for instance, beaten girlfriends. In early October, USA announced that the first season of “Rush” was also the last.

November — The lesson: Television viewers prefer society just the unfair, cutthroat way it is. “Utopia,” a fall reality series from Fox, intended to follow 15 strangers for a year as, isolated from the real world, they tried to build a better society. Viewers shrugged. Fox announced in November that the show was being pulled, utopia still unrealized.

December — The lesson: Television viewers hate fathers. “Dads,” an awful Fox comedy introduced in 2013, was put out of its misery. “Surviving Jack,” another father-centered sitcom from Fox, didn’t survive after being introduced in midseason. And as the year ended, Nick at Nite viewers were getting their last look at “See Dad Run,” with Scott Baio as the title father.