1. A satire on creationism; the two main characters travel back in time, intending to see the dinosaurs, but when they hit around 4000 BC or so, their time machine crashes and they get separated. The viewpoint character realizes he's been transformed into a woman in the crash and can't figure out why at first, until she discovers that there are not only dinosaurs around, but exactly two humans, Adam and Eve. And since Adam was by definition the first man, our time traveler got changed into a woman when he tried to go back before Adam was created. I think it was on FM but I'm not sure.

2. One of those stories where humanoid aliens invade and, not content with stealing our women, they want to change our men into women and steal them too. I vaguely remember that this one involved the aliens using some kind of genetically engineered vine, which would infiltrate its tendrils or roots into people's bodies and gradually transform them. And I'm pretty sure two of the transformed characters were father and son. I thought it was on Sapphire's Place but I'm not sure.