From an evolutionary standpoint, some enthusiasts and researchers consider the notion that if today’s pop, iconic aliens really do exist, then they are likely our own descendants from many thousands of years in the future.
In this case, they may or may not still be technically extraterrestrial, if only because some of our indeterminably distant grandchildren may well be born on another planet.
People frequently put forth the idea that “visitors” or “grays” are quasi-humans with inter-dimensional maneuverability of some kind. Without entirely ruling out ideas involving alternate or additional realities, focus, however, on certain consistently purported continuities of physiological traits between them and ourselves. These suggest a relatively simple origin much closer to home – one in which time, itself, presents the only real space separating this “alien” civilization from our own.
On the subject of their having come from another star system all together, the whole “astronomical time & distance to the nearest possible source…” argument becomes moot on an evolutionarily backlit stage. Extraterrestrial hypotheses regarding humans’ own beginning are not very viable, either, considering the ever-expanding paleoanthropological evidence from our fossil record.
Despite positive likelihood of ET life somewhere, the chances of us and our first and only contacts, together, exhibiting such similar, convergent anatomical evolution seem staggeringly improbable.
These creatures are depicted as being more physically like ourselves, even, than a bat is like a bird, or a dolphin is like a shark. Examples of parallel evolution between virtually unrelated species right here on this planet pale in comparison to these aliens’ uncanny resemblance to us.
Notice the apparent succession of contour facial features from archaic Homo sapiens all the way through the so-called aliens.
Any humanoid could initially appear to have a grossly exaggerated cranium and eyes if, in actuality, the surrounding structures were considerably undersized in proportion, including reduced (in thickness, not necessarily in definition) brow ridge, cheekbones, shoulders, neck, plus especially dwarfed jaw and teeth. The cranial capacity may be little larger (if any) than our own – perhaps eluding upon first impression.
There is reason to assume that, in the future, there may be even further shrinkage of our own vestigial Cro-Magnon-like protrusions or buttresses – continuance of the going trend. This applies to the entire postmodern physique, hypothetically making us a veritable missing link in ourselves.
Although scientists speculate that humans may evolve an even larger nose to adapt to airborne pollution, it is easy to envision standardized residential air filtration of some sort becoming a vital norm in the relatively near future. In a quite typical evolutionary response to increased reliance upon man-made apparatus, the nose may gradually recede, possibly even being a consequence of subterranean or submarine living with such respiratory support.
Although environmental conditions which influence human evolution are undoubtedly different today than they were thousands of years ago, one consistent and prevalent phenomenon which began long ago is the de-evolutionary effect which intelligent advancements inevitably have upon us.