So, here are a couple weird things about Superman I’ve never seen anyone comment on, though they’re so glaring it seems as though somebody must have.
First, Superman has a range of diverse and extraordinary powers common to his species, each of which would seem to represent a complex and independent evolutionary adaptation: Directed flight, near invulnerable skin, heat vision, X-ray and telescopic vision, freezing breath, and the underlying capability to absorb and store solar radiation that drives them all. These are powers any Kryptonian would exhibit when exposed to the light of a yellow sun. Yet Krypton’s sun, Rao, is not yellow but red: Kryptonian bodies not only are incapable of processing and storing its radiation for these spectacular effects, but seem actively weakened by it. That is, even when Superman has been absorbing normal amounts of yellow sun radiation and is fully empowered, relatively brief exposure to red solar radiation causes him to quickly lose these powers. So while all Kryptonians apparently possessed the same latent biological capabilities as Superman, all but the very earliest stories depict them functioning more or less as baseline humans while living on Krypton.
This ought to be somewhat mystifying in Darwinian terms. It would be like discovering that a species living exclusively in deserts had evolved fins and complex gills. It would be pretty much impossible for all these complex adaptations to emerge naturally in an environment where they would never be expressed, and therefore could confer no fitness advantage. That would leave two possibilities. One is that the Kryptonian genome had been artificially modified, presumably by another more advanced species, for some unfathomable reason, to imbue Kryptonians with extraordinary capabilities that would be suppressed in ordinary life. The other is that Kryptonians did, in fact, evolve under the light of a yellow sun—either Rao in an earlier phase of its existence, or another star from which the “Kryptonians” either migrated or were transplanted, losing their native abilities. However, with the exception of the Daxamites —a species descended from Kryptonian colonists, and also living on a planet orbiting a red sun—the otherwise extraordinarily technologically advanced Kryptonians are portrayed as a xenophobic species with little interest in space exploration. This would be especially odd if Kryptonians had all previously exhibited superhuman capabilities under the light of a younger, yellow Rao—since you’d expect the civilization to turn its technological prowess single-mindedly toward the task of reclaiming their genetic legacy, if they were aware of it. If the answer is that Kryptonian abilities evolved under a yellow Rao millions of years in the past, before recorded Kryptonian history, wouldn’t genetic drift have eventually rendered these vestigial abilities non-functional in modern members of the species? Or alternatively, wouldn’t that be sufficient time for Kryptonian physiology to have adapted to process red sunlight?
Second, Kryptonite seems fantastically improbable. Superman’s greatest weakness, as everyone knows, is his own former home planet: After it exploded, Krypton’s fragments passed through a “cloud of radiation” that transformed them into the familiar glowing green substance that is highly lethal to Superman, though apparently not immediately harmful to ordinary humans or other terrestrial life forms. Whatever radiation caused this effect does not appear to be common in nature: It is encountered almost exclusively via Kryptonite, though Superman has traveled extensively throughout the universe. We don’t find other bits of celestial debris, not originating on Krypton, that have been similarly transformed. Yet it also was present in sufficient quantity and concentration near Krypton that, as far as I know, all fragments of the planet Superman later encounters have become Kryptonite.
In other words, one of the only things in the universe that can readily kill even a yellow-sun-empowered Kryptonian is a form of radiation that seemingly exists nowhere in nature except around the former location of Krypton. Not close enough to have killed off the inhabitants of the planet, mind you, but apparently close enough that, excepting little Kal-El’s escape shuttle, nearly all matter ejected by the planet’s destruction has been irradiated. All that implies that this Kryptonite-creating radiation field must be present almost exclusively as, in effect, a large bubble around Krypton. That would, one supposes, account for the limited interest in space exploration, but it’s also s a hell of coincidence.
What’s really astonishing is that these two facts, especially in combination, don’t seem like random lapses in story logic, but rather seem to suggest a common explanation. A whole planet of Supermen would, of course, be one of the most terrifyingly formidable forces in the universe: Superman alone, after all, has been seen to single-handedly battle entire interstellar armadas. (Think of the Viltrumites from Invincible.) Individual organisms comparable to an adult Kryptonian seem to be extraordinarily rare, and when they do exist, they tend—like the “New God” Darkseid—to rule entire planets. So what’s the obvious inference when we find an entire species of these juggernauts living on a planet where their powers are nullified, surrounded by a bubble of extremely rare radiation that would kill nearly any spacefaring members before they could reach a star that would repower them? It’s sort of a no-brainer: Someone did this to them on purpose. You could imagine a benign hyper-advanced species like the Guardians of Oa doing it to a naturally evolved hyperpowerful species, maybe accelerating Rao’s transition to red giant phase and creating the—come to think of it, suspiciously greenish—radiation bubble, at least as a temporary measure until they’d cultivated a high level of peaceful civilization. Less benignly, maybe a species like the Engineers from Prometheus would want to keep an ultimate biological weapon in reserve, like a plague bacillus in a bottle.
The only really surprising thing is that, as far as I’m aware, no writers have decided to run with this obvious explanation for two otherwise bafflingly improbable facts. Never mind the bottled city of Kandor—I want to read the story of who bottled Krypton, and why, because it seems clear someone did.