Evelyn Gern is the last woman on Earth.
The Last Woman on Earth is a 1960 horror/scifi film wherein the temporary disappearance of oxygen destroys most animal life, including all but three Humans. Consequently, the cast is very small:
IMDB says 'Color: Color (Eastmancolor)', but when I saw it (Google Video) it was black and white--apparently they made it black and white for television. Runtime of 71 minutes.
It's not a great film, but not dreadful. A bit slow if you're used to modern blockbusters, and the two fight scenes are somewhat lame, but it's not about the cinematics at all. It's about the characters' conflicts. Three people survived and that one chick is the last woman on Earth!
How the world ends (Spoilers!)
It starts with Harold and Evelin at a cockfight in Puerto Rico. Harold Gern is a rich guy. Evelyn is his somewhat unhappy wife--apparently Harold is all work; somewhat distant. He's also under investigation--again. His young lawyer Martin keeps trying to get Harold to take stuff seriously, but Harold likes gambling and the like. But this is all just prelim. It all really begins when the three of them go skin diving. Upon surfacing, they feel faint, so they keep their oxygen masks on, discovering the boat driver is dead. They return to shore and find themselves able to breathe in the forest--a good thing since their tanks are empty. They realise that while they were under water, all the oxygen temporarily vanished, but that plants are restoring it. Sadly, everyone is already dead. Everyone in town, at least, and seemingly everyone everywhere.
The three of them hang out at Harold and Evelyn's house for a while, but two guys and one woman = trouble. Harold gets them organised--they fish (apparently the fish didn't die) and upon the discovery of insects (it's presumed they were in egg-form at the time of the disaster), he concludes they may have to travel north to avoid a major pest problem, what with there being lots of dead bodies to feed the insects. (I should note, however, that birds appear as well, and it seems unlikely that they were in egg form at the time, as they've learned to fly. Infant birds usually require parents.)
Martin and Evelyn are less enthusiastic about all this. The world ended, and they don't have 'a system' like Harold does. His system isn't theirs, claims Evelyn.
Eventually, Evelyn and Martin get together, so Harold and Martin fight and Harold kicks out Martin, who asks Evelyn to come with him, and she does. Harold catches them, though, and the guys fight some more, and eventually Martin dies. 'I killed him. Will we never learn?'