I remember them being part of an archive, a collection of short stories. Incredibly vague, I know, but I have some information that would be sure to make someone remember if they too have read some of these stories.
The first story had the following basic plot: Essentially, in order to go faster than light mankind had to send out ships to make stargates, and over millions of years the humans on board are dwindling to ever lower numbers, whether due to suicide, depression, madness or simply not wanting to wake up from cryo-sleep. This leaves our narrator of the story, talking about how he is woken up from time to time to work on the ship and basically make sure it is functioning. He tells of strange happenings, and how most human beings in existence look nothing like him at this point (he being an "original", so to speak, an unevolved human-being), and has found himself disgusted with what he sometimes sees out there.
At one point there is a woman who looks exactly like what one might think a human would look like, one with magical powers and such who happened to stick around long enough for the man to actually notice when she went missing one day in the massive bowels of the ship (it's never disclosed, I think, what happened to her). Eventually as the short-story begins to finish up, the narrator mentions and laments the fact that nobody really human or human-derived has actually made contact with the ship, and the closing line is something along the lines of "Why have you forsaken us?"
The second story: A man embarks in a single-crew ship to undergo the trial of an FTL device, and fortunately it works. The bad news is that he lands on an alien planet, and finds an incredibly evolved creature that does a truly terrible thing to the human and degenerates the man mentally into that of an animal. The story is from the perspective of the human animal in trying to get "revenge" on having something (though said human animal is not sure what) from it. It ends with the human astronaut indeed getting his revenge and making his way back home, only for all of his friends and coworkers seeing him and becoming terrified of what terrible changes they see in the main character's eyes.
Unfortunately I cannot give any concrete details in regards to when I saw it, other than that it was around a decade ago and that all were original stories (further unsure if they were ever actually published, but I do know they were not some small story in a greater novel.)