Behind Thanos’s killing spree in Avengers: Infinity War (2018) is a chilling rationale: the population across galaxies is exploding, resources are finite, and wiping out half the universe ensures that the remaining inhabitants have enough food, water and energy. It’s a justification that real-life demagogues have also employed for their population-wiping quests in the past – Adolf Hitler, for one. Unlike his predecessors, Marvel’s purple villain did not want to differentiate based on race or class.

This fear of rapid population growth has special resonance in India. Is this one of the factors behind the film’s stupendous success? Avengers: Infinity War on Friday became the first Hollywood movie to earn more than the Rs 200 crores in India.

Thanos’s mission of decimation has many precursor. In Ron Howard’s Inferno (2016), an adaptation of Dan Brown’s novel of the same name, wiping out half of humankind is the only way to save the world from impending doom, according to billionaire geneticist Bertrand Zobrist. For Zobrist, Dante’s 14th-century epic poem Inferno is an apt metaphor of the present. A genocide, via a virus, is the only way to pull humankind out of hell. To thwart his plans, history professor Robert Langdon (Tom Hanks) has to go on a puzzle-solving quest through Italy.

Inferno (2016).

Concerns about overpopulation have resonated with science fiction movie makers over decades, their versions of dystopia often featuring a crowded, squalid planet on the brink of destruction.

In Richard Fleischer’s cult classic Soylent Green (1973), this post-apocalyptic world unfolds in the then-distant 2022. In this universe, where the world is so overpopulated that a building lobby resembles Churchgate station at peak hour, food is in such short supply that people survive on laboratory-made crackers.

Fruits and vegetables are the luxury of the elite, and fresh meat even harder to find. A company named Soylent controls half the world’s food supply. Its delectable offerings include a green wafer enriched with plankton from the oceans. When a member of this corporation is found dead, police detective Frank Thorn (Charles Heston) chances upon documents in his house that reveal that there is more to Soylent than meets the eye – or tongue.

The environment’s conscience keeper is Thorn’s elderly friend and police analyst Solomon Roth (Edward G Robinson), who had lived through a time when “food was food” and people could experience the simple pleasure of watching the setting sun, or seeing flowers dangle in the breeze. Sol finds it hard to come to terms with what the world has come to and frequently references the Greenhouse Effect.

Soylent Green (1973).

In Z.P.G (1972), a Danish-American film by Michael Campus, Soylent’s crackers are replaced by a bright paste as the only source of nutrition. Pollution levels are so staggering that all animals are extinct. To arrest this slide, the government decrees zero population growth for 30 years. Anyone who bears offspring will be punished by death. However, when Carol McNeil (Geraldine Chaplin) gets pregnant, she and her husband Russ (Oliver Reed) seek to defy the authorities and keep the child.

Z.P.G (1972).

Controlling reproduction is the tool of choice to fight overpopulation in many other movies. In thriller Fortress (1992), directed by Stuart Gordon, former army officer John Henry Brennick (Christopher Lambert) and his wife Karen (Loryn Locklin) are imprisoned when trying to cross the American border into Canada to give birth to their second child. Their home country has a strict one-child policy. Brennick is kept in a maximum security prison, where torture techniques include mind control and memory wipes. The unborn child, meanwhile, is deemed the property of Men-Tel, a corporation that owns the prison. A sequel, Fortress: Re Entry, was released in 2002.

Forest (1992).

More recently, the premise was explored in Norwegian director Tommy Wirkola’s What Happened To Monday (2017). In a quasi surveillance state with a strict one-child policy, any sibling found is seized by the Child Allocation Bureau and put into a cryo-sleep – a hibernation of sorts from which they may awaken if balance is ever restored in the world.

The movie’s implausible premise centres on Terrence Settman (William Dafoe), who decides to raise identical septuplets, which he names after the days of the week. All of them assume one common public identity, Karen Settman, and can step out only on the day of the week that corresponds with their name.

Though with vastly different personalities, the seven sisters (played by Noomi Rapace) manage to play Karen to perfection on their designated days for many years, but lead an otherwise lonely and claustrophobic existence. When Monday goes missing after work, their secret is revealed and the Child Allocation Bureau comes after them with a vengeance.

What Happened to Monday.

Other movies envision a dystopia where the population is wiped out after a certain age. In Michael Anderson’s Logan’s Run (1976), the life span is curtailed to 30. The movie is set in the 23rd century, a time when much of humanity has been destroyed by war, overpopulation and pollution. The remaining few live in a domed city and as is science-fiction’s worst nightmare, this enclosure is controlled by a supercomputer.

During their brief existence, humans lead a hedonistic life of utmost comfort – “mankind lives only for pleasure” – but all of them have a crystal embedded in their palms that serves as their life clock. As they inch closer to 30, the crystal turns red, and when their time is up, they are eliminated in a bizarre death ritual known as the Carousel – they are vapourised on a rotating disc in an auditorium as a crowd looks on and cheers. Those who try to escape the Carousel to flee death are termed “runners” and are eliminated by Sandmen, an elite police force in the domed city.

When Sandman Logan 5 (Michael York) goes for his routine meeting with the supercomputer, he is told that that over the years, some runners have managed to escape and seek refuge in something known as the Sanctuary. His task is to find the Sanctuary, for which he is forced to become a runner himself. The film’s recreation of a 23rd-century universe are fascinating, if sometimes amusing, and the film won a Special Academy Award for its visual effects.

Logan’s Run (1976).

The antagonists in The Thinning (2016), directed by Michael Gallagher, believes in catching them even younger. It’s 2039, and to counter overpopulation, the United States of America decides to eliminate 5% of its citizenry every year. This is done by subjecting school students to an annual test, and the lowest performers are killed. While other countries are experimenting with one-child policies or filtering out senior citizens, America opts for survival of the smartest in its quest for global dominance.

Exams have never been as stressful as they are in The Thinning, where children as young as six and seven are escorted into examination halls and put to a death-defying test. Those who fail are whisked away by masked security guards on the spot.

When the governor’s son Blake Redding (Logan Paul) decides to deliberately fail his test one year in defiance, it is revealed that the assessment system may not be impartial after all. As a result, Blake is safe despite his abysmal grade, while Laina Michaels (Peyton List), the smartest student in class, is sent for the thinning. What follows is an hour-long chase down the school halls as Laina tries to escape her executors with Blake’s help.

The Thinning (2016).