Devious sci-fi aliens have hatched many plots to conquer humanity, from the Machiavellian Martians of "The War of the Worlds" books to the current hit movie "Oblivion." However, the invaders' ambitions frequently fail, perhaps because nature has already tried many of these assaults on us or other species.
Here are eight ways the natural world has outdone the best laid plans of Martians.
Jens Petersen, Wikimedia Commons
In the classic alien attack scenario, invaders try to overwhelm puny Earthlings by sheer force, as in "Independence Day." Sometimes, space villains use monstrous beasts to do their dirty work, such as in "Prometheus" or the Godzilla flick "Destroy All Monsters."
In the real world, invaders already swarm over the face of the Earth. Invasive species have devastated many ecosystems and cost humans billions of dollars in agricultural losses and infrastructure damage.
However, some wildlife, such as American birds that feast on invasive honeysuckle, have learned to turn invaders into appetizers. Humans too make prey of invasive species by hunting feral hogs and Burmese pythons and eating animals such as lionfish (shown here).
A giant eruption of solar material over 20 Earths long shooting off the lower right side of the sun on July 7, 2012.NASA/SDO/AIA
Klaatu and Gort, the alien visitors in 1951’s "The Day the Earth Stood Still," knocked out humanity's ability to use electronic devices and crippled the world’s military forces in an effort to enforce world peace.
The sun pulled a similar stunt on March 13, 1989, when a stellar storm launched a solar flare that disrupted electricity transmission from the Hydro Québec power plant in Canada. The resulting blackout left approximately 6 million people without electricity for 9 hours, according to NASA.
An even more powerful solar storm in 1859 caused telegraph systems worldwide to malfunction, zapping operators with electric shocks and setting telegraph paper on fire.
The brain slugs of "Futurama" and pod people of "The Invasion of the Body Snatchers" exemplified the term control freak. Hijacking humans’ brains allowed these bossy beings from beyond the moon to force humans to do their bidding.
Cat owners may sometimes worry that they are pawns in their pets' plans for world domination. However, it is actually a parasitic microorganism in cat's poo that has mind control powers. The parasite Toxoplasma gondii alter rats’ brains to make them sexually aroused by the smell of cat urine, thus making the confused rodents more likely to be eaten, according to research published in PLOS ONE. Once the rat enters the cat, the parasite’s life cycle continues after the feline’s infected poo passes the parasite on to other rats.
Humans infected with the parasite also show behavioral differences from the uninfected. A study published in Archives of General Psychiatry found that women harboring Toxoplasma were one and a half times more likely to have attempted suicide.
Shanghai killer whale, Wikimedia Commons
In the campy 1960 film "12 to the Moon," an alien decides that humans pose a threat and freezes the planet. However, as the cast of "Mystery Science Theater 3000" noted while lampooning the cinematic stinker, that kind of weather wouldn't even faze the Midwest.
Two words for any alien that thinks they can chill out Homo sapiens: Ice Ages.
Humans evolved while nature threw snowballs at us during the Ice Ages. Nowadays, we keep an outpost alive in the frozen desolation of Antarctica. Some people like the cold so much they join the polar bear club and jump into frozen lakes. If the planet was frozen, people might even make a festival of it, such as the Harbin Snow and Ice Festival in China (shown here).
Fredric Remington, Google Art Project, Wikimedia Commons
Extraterrestrials shape-shifted into human form to trick people and seize power in "They Live," "V" and "The Simpsons Halloween Special VII."
Trying to gain the evolutionary advantage by creating a case of mistaken identity has been around for ages on planet. Animals use mimicry to fool other species and gain survival benefits. Humans too use camouflage to look like other animals. For example, Plains Indians used to disguise themselves as bison, as in this painting "Indians Simulating Buffalo" by Fredric Remington.
Shane Torgerson, Wikimedia Commons
The Vogans destroyed the Earth to make room for a hyperspace by-pass in Douglas Adams' "Hitchhiker's Guide to the Galaxy." It wasn't so much conquest as construction.
Don't Panic. Real life attackers from space, such as asteroids and comets, have been bombarding the planet for billions of years leaving scars like Meteor Crater in Arizona (shown here).
Some scientists suggest that the organic building blocks of life or even living organisms themselves were brought to Earth by space debris. Chemists recently simulated the conditions of deep space and found that amino acids chains essential for life could be formed on icy space debris. The study was published in The Astrophysical Journal.
NASA Earth Observatory
Extraterrestrials seeking to bring the Christmas spirit to Mars kidnapped Kris Kringle in the silver screen gem "Santa Claus Conquers the Martians."
Old St. Nick has enough to worry about with our Martian mischief. Climate change is melting Santa's Arctic workshop on the sea ice of the North Pole. However, even with a melting Arctic, Santa still manages to deliver toys to all the good boys and girls.
From January through March of this year, a massive crack (shown here) formed in the Arctic sea ice, which has become thinner and weaker as the planet has warmed up. On March 15, the Arctic sea ice reached its maximum extent, but it was the sixth smallest on record, according to the National Snow and Ice Data Center.
A facial reconstruction of a 14-year-old girl whose remains found in Jamestown, Va. suggest she was cannibalized.Artist: StudioEIS; Photo: Don Hurlbert, Smithsonian
In a classic "Twilight Zone" episode, To Serve Man, aliens come to Earth proclaiming they want to serve humanity. Too late, humans realize that there the word serve has more than one definition. The aliens plan serve humans as meals.
Aliens can't devour us if we devour ourselves first. Cannibalism occurs frequently in nature, as anyone who has witnessed a pet mouse eat her own babies can attest. Human cultures haven't been above cannibalism either. For example in protein-starved New Guinea, cannibalism was once an accepted way of life. Other groups have resorted to cannibalism in emergencies. During the "starving time" in Virginia's Jamestown colony, settlers resorted to butchering a 14-year-old girl, reported the Smithsonian.