Why Do They Look Like Us?

Skeptics often pose the question: If we are being visited by aliens from another planet or dimension, why do they look so much like us? Why should they walk upright on two legs, with two arms, two legs, a head with two eyes all placed in the same general location as our own? Its reasonable question. All of the alien types we believe exist, the reptilians, The mantis-like insectoids, the Nordics and the iconic grays share with us the same basic configuration in spite of the likelihood that they evolved completely independent of humanity. shouldn't they instead look completely different from us? shouldn't they appear alien?



Science fiction never had this problem. In his classic War of the Worlds, H.G. Wells reasoned that a being from another world should look otherworldly.  He described a tentacled bear shape like a brain crawling. Taking Wells as inspiration SF writers imagined a zoo of intelligent species.  Edgar Rice Burroughs gave his Martians four arms and improbable tusks,  Frederick Brown described a globular being with tentacles, Heinlein depicted a noble giant dragon capable of extremely delicate work using its incongruously tiny hands.  Larry Niven, in his Known Space stories described his Puppeteers as tripedal, two feet in front, one in back, with the brain between the shoulders.  An eye and a "mouth" with manipulating mandibles were set in each of two tentacles coming from both sides of the shoulders.  Descended from grazing animals like deer the entire species were natural cowards.

Our collective experience with interviews of those people who have been contacted by aliens reveal none of these.  All of the aliens are bipedal humanoids.

Evolution fills niches like water naturally seeking it's own level.  A species will evolve into a certain appearance that functions well in the niche it lives in.  A land predator has four legs, sharp binocular vision with eyes that can be raised above it's body so that the rest of it will remain concealed.  The ears are designed for maximum sound gathering and can swivel, but are most efficient when directed forward.  It has very capable claws and teeth.  Jaguars, tigers, wolves, Tasmanian  wolves, hyenas, and dogs all share these characteristics because they are the ones that work and survive to pass these traits along to the next generation.  Similarly all birds have the same basic form expressed in many variations. 

The so called humanoid form is simply the best that we can imagine for and intelligent species.  First it is bipedal allowing the being to stand up straight and have the greatest field of view.  the eyes and ears are close to the brain so that the information from them will be received soonest.  The brain in at the top to allow for maximum cooling and is protected in a hard skull.  The forelimbs, freed from walking or running can be used for manipulation of objects which in later evolution inevitably become tools igniting the further evolution of grater intelligence.  The bipedal upright humanoid for may in fact be the only form an intelligent species may take.