Humans have an 'opposable thumb'.
(..) hippocampus preventing the conversion from short-term to long-term memory? Okay, now you're starting to make me mad. A homo habilis discovering his opposable thumbs says what? What? I think I've made my point. Yeah? How about I make a point out of your pointy little head? (..)2007 TvShow: The Big Bang Theory Title: The Middle Earth Paradigm Season: 1 Episode 6