Aliens have been stereotyped. What Hollywood thinks extraterrestrials look like like has manifested into humanoid life forms with a disproportionately large head, huge eyes, and reptilian skin.
H.P. Lovecraft’s more exotic and horrifying visions, however, might be closer to the truth out there.
This doesn’t mean that what we’ll find, if we find it, will necessarily greet us with 19 eyeballs, rows of razor teeth, and miscellaneous appendages (though they might). Humans have just been too close to human when imagining life on other planets. In a recent report, NBC Mach disagreed with Oxford University's claim that aliens are possibly more like us than we think. The thing is, for something that lives a billion light-years away to appear and function like us, it also needs to have evolved in a strikingly similar environment. This is what biologists call convergent evolution. Now think of how many exoplanets we’ve discovered that actually mirror Earth.
You’re right on if you’re thinking zero. Even planets in potentially habitable zones, like several in the TRAPPIST-1 system, are nothing like our own, as observations beamed back from deep space have revealed. Some environments are blistering hot and face a daily onslaught of deadly radiation. Others are beyond freezing. Then there are those that may not need infinite SPF or self-heating space suits, but that have atmospheres swirling with toxic chemicals. If you’re an organism that is somehow still alive under any or all of these circumstances, survival is a priority (at least for our species), and that could mean evolving in a way that defies sci-fi movies.
If a species can successfully self-replicate, that means it’s doing something right — at least until the next deep freeze or asteroid impact. Just look back at what existed on a much younger and more volatile Earth. Our planet was crawling with microbes for 3 billion years before primitive organisms merged with each other to create things that could survive the primordial sludge, but looked nowhere near humanoid.
Fast-forward to 400 million years ago. Lovecraftian-looking creatures like trilobites and orthoceratites dominated the oceans (no evidence of R’lyeh), and land was overrun by monster mushrooms known as prototaxites. 100 million years ago, feathered lizards you wouldn’t recognize in any zoo’s menagerie darted after their prey. Even humans are said to have evolved from fish, which sounds kind of like an inverse version of The Shadow Over Innsmouth.
Earthlings tend to be partial to the conditions on our planet. We tend to search for life as we know it, versus anything that could be alive but totally unrecognizable. We can’t assume that any planet with a diverse bestiary necessarily has an oxygen-rich atmosphere and oceans of liquid water, because the Gaian model can in no way account for hypothetical organisms that could have evolved breathing carbon dioxide or swimming in methane. What they look like depends on the functional and protective aspects they have evolved to keep passing down their DNA. Their planets of origin may be potentially fatal to anything that spawned here, but to them, Earth could translate to vats of acid and poisonous fumes.
Somewhere in the vast cosmos, Lovecraft’s voice is echoing through time and space, telling us the Mi-Go were real all along.