Mankind has long been captivated by the concept that alien civilizations may exist somewhere in the vastness of outer space. There is no shortage of fantastical stories that imagine what alien species may look like, talk like, or even mate like. While certain particularly creative works of fiction, like Arrival, depict extraterrestrial beings as completely foreign to humanity in terms of biological makeup, phenomenology, and language, other more mainstream versions of alien life forms are very anthropomorphic and far less nuanced.
Because these alien tropes are so widespread, popular culture’s default vision of extraterrestrials has grown into a laughable caricature of itself. Here are some of the silliest assumptions about life from other worlds from popular fiction.
Aliens Are Basically Just Humans With Small DifferencesPhoto: Star Trek:The Original Series / NBC
The Trope: Aliens are just like us, except green! In this trope, extraterrestrial life forms are imagined as bipedal creatures that look more or less human but with small tweaks. Usually this comes in the form of an unusual skin color, like blue or purple. Their eyes may be larger or completely black, or there may be strange appendages on their heads, but overall they’re pretty much just like earthlings in most ways that count.
Why Is It Inaccurate? If life did exist somewhere in the universe, it would almost certainly not have evolved in a way that resembles humans. With the incredible diversity of planetary environments that develop in other solar systems, the worlds that could host life would most likely differ from Earth in a staggering number of ways - the temperature; atmospheric pressure and constitution; presence of liquid or solid areas; and possible food sources would all be foreign to those on Earth. To survive in these different places, life would need to take a very different form than we would recognize.
Notable Offenders: Star Trek’s Vulcans are essentially just humans with pointy ears. Star Wars, while slightly more complex in its depiction, also follows this trope. Chewbacca is a person covered with hair and given a dog-like face, and Yoda is a person who is small and green with big ears. Perhaps the most flagrant offender of this bunch, however, is the Marvel Cinematic Universe; most of the alien species are just people with technicolor skin and maybe one odd physical feature added (looking at you, Thanos).27244Seen this a lot?
Sexy Humanoid Aliens Definitely Reproduce Like MammalsPhoto: Mass Effect / Electronic Arts
The Trope: When it comes to anything - anything at all - people will inevitably (and, most of the time, very quickly) start thinking with their crotches: If aliens exist, and they’re a lot like people, can we... you know, do it? This trope is an incredibly popular one for fairly obvious reasons.
Why Is It Inaccurate? It’s a stretch, but not impossible, to think that emotional attachment could spark up between two highly intelligent members of biologically distinct species, but things get really silly when we imagine that aliens would reproduce in even remotely the same way that humans do. The myriad different ways of reproduction within our planet’s different life forms alone show how utterly implausible this trope is. Chances are slim to none that we’re "compatible" with the Martians.
Notable Offenders: The Mass Effect series has gone to town with this one, offering a number of human/alien romances, complete with steamy cinematic scenes. Yet perhaps the most brazen example of this trope is from Star Trek. Spock’s very existence is a puzzling one; he’s half human and half Vulcan, because somehow these species that evolved on two totally different planets are reproductively compatible. Yes, there are "explanations" for this, but they are weak to say the least.18245Seen this a lot?
Aliens Are Capable Of Coming To Earth With An Arsenal Of Futuristic Weapons, But Haven’t Destroyed Themselves In The ProcessPhoto: Independence Day / 20th Century Fox
The Trope: A hyper-aggressive force of aliens arrives on Earth with weaponry far more powerful than anything conceivable by humans. We are helpless against their highly advanced technology as they invade and take over the planet.
Why Is It Inaccurate? One of the answers to the Fermi paradox, which focuses on the reasons why we haven’t been able to find intelligent life elsewhere in the universe, is that any civilization with advanced-enough technology will inevitably become extinct before it is able to make contact with other worlds. A variation of this answer contends that any civilization with super-advanced weaponry would first turn that deadly force on its own people. According to this theory, it’s more likely that aliens would have succumbed to local infighting or any number of other disasters before uniting their culture planet-wide and taking a quick jaunt around the universe to conquer other worlds.
Notable Offenders: The plot of Independence Day focuses on a ruthless invasion of aliens with impossibly advanced weaponry and spacecraft, as do Battle: Los Angeles and War of the Worlds.18851Seen this a lot?
They Can Breathe OxygenPhoto: E.T.: The Extra-Terrestrial / Universal Pictures
The Trope: Earth's atmosphere of oxygen and nitrogen proves to be safe and breathable for life forms from other worlds. They simply leave their spacecraft and step out into the open, taking deep, refreshing lungfuls. They do not require protective suits or tanks of breathable air.
Why Is It Inaccurate? If life can evolve at all, it must initially survive without any oxygen whatsoever. This may mean that it's more likely than not for a species to evolve that has no use for oxygen. It is also necessary for a huge, complex system of plants to keep enough oxygen in the atmosphere to be useful as a resource for living creatures like humans or other animals. Because of all these complicated elements and how diverse the atmospheres of other planets are, the chances that aliens' bodies would be totally compatible with Earth's specific atmospheric cocktail are vanishingly small.
Notable Offenders: E.T. is somehow able to survive by breathing oxygen, no problem. To be fair, his home world is called "the Green Planet" and as such most likely had a large amount of plant life, but this could also possibly mean that Earth's atmosphere might be too thin in oxygen for him to survive. There are even some fan theories that suggest the atmosphere is what made him sick toward the end of the film. Additionally, basically every alien species in Star Wars shares environments that clearly have oxygen enough for the human characters. What are the chances of that many different native planets all sharing relatively identical atmospheres?13528Seen this a lot?