[Verruckter]

One cause of our brain's expasion is that before (a looong time ago) "humans" only ate fruits and nuts. Since thier bodies where lacking of proteins contained in meat, they didn't evolve very fast. But at one moment, "someone" (i think he was homo-erectus) invented what would be a primitiv knife, and they used that knife to cut out meat from animals. Their brain then got bigger, and stronger.