2014-08-07
Explanation
The Joke
A man has fallen into a well and calls for help, explaining that he "thought there was leprechauns in here so I leaned over and fell in." A superhero wearing a costume with a "D" on his chest appears at the top of the well and declares: "Don't move! With my help, this fate will never befall anyone in the future!" The caption reads: "The Darwinist was not a popular superhero."
The Humor
The joke plays on the concept of Darwinism and natural selection. A conventional superhero would rescue the person in danger. The Darwinist, however, interprets his mission through the lens of natural selection: rather than saving the man, he plans to let the man's foolishness remove him from the gene pool, thus ensuring that "this fate will never befall anyone in the future" -- because the kind of person dumb enough to fall into a well looking for leprechauns will not survive to reproduce.
The man in the well is clearly not the brightest (believing in leprechauns, falling into a well), making him a perfect candidate for a "Darwin Award" -- the darkly humorous concept of people who improve the gene pool by accidentally removing themselves from it. The Darwinist superhero's "help" is actually to do nothing, which is the exact opposite of what a superhero should do.
References
Charles Darwin's theory of natural selection proposes that organisms better adapted to their environment tend to survive and reproduce. The "Darwin Awards" are a tongue-in-cheek honor recognizing individuals who have supposedly contributed to human evolution by selecting themselves out of the gene pool through remarkably foolish actions.