Unlike the widespread reporting of the credulous media, the human skull is not specifically evolved to take a punch from other humans. Brian Switek explains the many problems with this hypothesis at National Geographic’s Phenomena. I admit that I thought, throughout my rugby career, that my head, and only my head, had evolved to be punched. It turns out that the way I played rugby had evolved to make people want to punch me in the head1. I was a particularly annoying person to play rugby against2.
Fortunately, human skulls are pretty robust in some key ways. It is just very unlikely that they got that way due to the evolutionary pressure of hominids punching each other in the noodle. One of the key problems with the punching hypothesis is that it is pure conjecture (and unreasonable conjecture, at that) without supporting experimental evidence. What would it take to really test the punching hypothesis?
WARNING: This post may contain a Game of Thrones spoiler “below the fold”.
The Finch and Pea 