An Explanation
Whoa, got a little too advanced for you, I guess. Where were you born, a barn? Scientists started addressing their options, what was going to happen when the Earth went kerplunk. The first theory was that the human race would have to move underground. That’s where vampires came in. Far from the blood-sucking, cultured souls of the old Anne Rice novels, the created vampires were given light-sensitive eyes and skin, better suited to subterranean environments.
Vampires were the first project shelved, when they realized that tunnels would just flood and screw everyone over, and that the sun would toast the delicate skin they’d so painstakingly engineered. Then came the sprites. Sprites were made smaller than people were, on average, only growing about 4’5’’ as adults. Photosynthetic cells were injected into their skin and organs, so they could use the sun’s energy as food. They didn’t burn up in harsh UV light, and they didn’t require much food (just water).
They got ruled out, though, when it happened.