It was mentioned on a biology blog that archaeological engravings from the Tiwanaku civilization in Bolivia are unlikely to be depicting an ancient astronaut for the reason that, even with an aquatic tail, the creature still looks too much like a human. The underlying argument was that the evolution of life forms is so diverse that it is highly unlikely an alien would come out looking even remotely like us. In essence, this is the opposite side of the pendulum to Hollywood’s consistent imaging of aliens as humanoids.
The biologist ignored the decorative and symbolic imagery added by the Tiwanaku artists and did not consider the given premise of an aquatic alien inside helmeted spacesuit. I have to assume, therefore, the biologist noted that the creature had two arms and two eyes, and since humans have two arms and two eyes, the biologist concluded that this cannot be an alien.
What should intelligent aliens look like? Or, to phrase it another way, what should we expect interstellar travelers who come here to look like? This is not a complete unknown. If the aliens are capable of interstellar travel, they obviously achieved higher technology. What is...