I think that the vision of human origins offered in the episode is reflective of the "Adam and Eve" narrative presented in the Book of Genesis. It is a narrative of human origins that stresses creation as a result of massive destruction, something that might differ than the Biblical telling. In the episode, the rocket pilot and the woman are responsible for repopulation of the Earth. The episode features the idea that human beings are and can be seen as responsible for "starting anew." Yet, the intimation that human beings are capable of ruining this opportunity is evident when Norda offers the pilot a "seppla," or type of forbidden fruit. This indicates that while humans have the chance to start anew and regenerate a chance to "get things right," there exists a tendency to embrace evil or show propensity to do damage to that which is seen as a chance to do good. In this, I think that there is a fundamental element of destruction and creation that is within human beings and something that is brought out about the creative elements of individuals. In this, the episode brings out how the origins of human beings are both linked with promise and possibility as well as despair and ruin.
I believe you are referring to, "Probe 7, Over and Out" -- a 1963 episode of The Twilight Zone.
The episode seemingly featured an Earth astronaut being stranded on a planet alone because his home planet was being destroyed by war. Upon exploring his new "home", the astronaut discovered another "alien" [a female] who had also been stranded. As the couple struggled to survive and share knowledge with each other, they realized they were both going to be there forever and they slowly evolved into a "couple."
The surprise ending is that the astronaut (named Adam) gave the girl a simplified name (Eve) -- and they named the planet Earth. Speaking of pronouncing words, an interesting tidbit here is that "Eve" speaks English in reverse ("Di ekil ot omec thiw ouy").
This is actually one of my favorite episodes because of the "origins" connection. I've always been fascinated with science and faith, so this was interesting. It does take God out of the equation, but it really brings the "Ancient Aliens" idea to life.
The odds of two completely different alien species being evolved to the same point [and of the same genus and species] that they could reproduce enough to populate the planet is a little hard to believe, but if you think about an ancient race crash landing on an empty planet and beginning to populate it, it's not that farfetched.
If nothing else it's a great sci-fi story with something cool to think about.