OK, there are plenty of coincidences out there. There are a finite number of ideas, and it's only makes sense that sometimes different folks will come up with similar ideas at virtually the same time, at different places. Think
Swamp Thing/Man-Thing, whose debuts were separated by two months, or
Doom Patrol/X-Men, which came only three months apart.
But sometimes you come across coincidences that are so unlikely, so staggeringly impossible, that you wish you'd bought a lottery ticket that day.
We start with the classic
Star Trek episode
Miri. Here's a trailer:
Long story short, the Enterprise finds a planet
100% exactly identical to Earth (which is kind of silly, and completely gratuitous to the story, unless you really want to hammer on the "it could happen here" lesson). A few centuries ago, a plague (created by ill-advised biological experiments) killed off all the adults, so only kids survived.
Meanwhile, in
Action Comics #344,
Supergirl, while doing stuff in space, encounters...
a planet exactly like Earth!!
Well, that can happen. But that's probably the only similarity, right?
Except
Kara finds that teenagers are the authorities on this world!!
And not only that...
A plague wiped out the adults!!
On a world identical to Earth.
And now the youngsters are in charge!!
Now, clearly, these are
not identical stories--there are
substantial differences. But for these two tales with similar starting premises, to come out at close to the same time, boggles the mind.
Of course, someone at
DC could have been acquainted with someone at
Desilu (and vice versa, of course), and overheard something, and maybe subconsciously adopted parts of the others' idea. Or it could just be two different sets of creators tapping into the same bit of flotsam in the contemporary zeitgeist.
Say, which story came first? How close were they in appearing?
Miri first aired on
NBC on
October 27, 1966.
And according to the Library Of Congress, Action #344 was published on...
October 27, 1966.
Mind. Blown.
I mean, what are the freakin' odds..?
BONUS FACT:
The BBC banned the Miri episode for 2 decades after some viewers complained. Also banned:
Plato's Stephcildrem, Whom Gods Destroy, and
The Empath. Go figure. Sorry, British Trek fans of that era.
BONUS FACT II: In the Action Comics story,
Linda Danvers was elected president of America on this "duplicate Earth":
This was 5 1/2 years before
Prez. And nearly 8 years before they met:
You'd think Supergirl would have mentioned having been a teenage president herself to him...