I have been watching some science fiction videos on YouTube which describe human-like aliens in other galaxies. Assuming they might exist, I wonder about any connection between anthropomorphic physiology and higher intelligence. For example, it seems plausible that such beings would be warm blooded in order to provide a constant source of nutrients for the brain. Other prerequisites might be an upright bipedal structure to allow for more specialized appendages and binocular vision to aid in three dimensional perception.
What do you think of these as necessary traits? One could also add a long gestation period (as opposed to external eggs) and a hybrid eating/breathing/communication system. (Maybe the only independent variables would be ear shape and eye/skin/hair color.) Since none of the other life forms on Earth show any potential for developing higher intelligence, maybe the same would be true for other worlds?
Too many counter-examples here on Earth ... monitor lizards are quite advanced and still cold-blooded ... plotting, deception, scheming, thieving ... all signs of higher intelligence ... honey bees as a hive are amazingly smart, yet with six legs ... most birds have binocular vision ... what all these have in common is respiration, taking in oxygen and breathing out carbon dioxide ... that would certainly be a requirement for any life as advanced as pond scum ...
Anne McCaffrey explored a reptilian form with six appendages in her
Pern series ... and an intelligence completely alien to human's ... although later, Ms McCaffrey visited a dolphin pen and said they were very very close to her dragon-kind ... except for the breathing of fire I suppose ... H.G. Wells' Martians in
War of the World were three-limbed ... but with intelligence just like ours: "kill what's not like us" ... that's fiction and maybe there's evolutionary economy best served by four limbs, as we find in our reptile lineage ...
Nothing is beating songbirds for complexity of communication ... all reptilians have vocal cords, including all birds ... in addition, songbirds have an oscine structure at their tracheal branch, where the air pipe splits into two ... and that's what makes the vast variety of complex communications ... one could say bird brains are more and better evolved, they can sing these songs and fly all with ... you know ... tiny bird brains ...
Are cosmic events involved? ... our Moon causes the tides and without those ... does life ever colonize land? ... how about an enormous meteor like the one 65 million years ago ... could humans evolve if dinosaurs still occupy the megafauna niche? ...
Birds are bi-pedal ... they use their arms for better things ... like flying ... same with humans, except we use our arms to carry things ... a chimp has to leave his tools behind when he moves with the food supply, humans could carry their tools with them, saving time and resources ... AND it was worth making the tools better, giving their design more thought ... which lead to better intelligence ...
The rodents got chased by carnivores into the trees and evolved into primates ... when the trees got full, the extra rodents jumped to the ground and got eaten ... "It's the Circle of Life, young Simba" ... until one came that tasted really really bad, so bad that nothing ate it ... and the little semi-evolved hairless rodents scampered about stealing food and resources driving everything else into extinction ... now they cover the planet make life impossible for everything else that lives ...
I just hope the aliens aren't hungry when they get here ... or they're in for a nasty surprise ...