In Star Trek First Contact, the Vulcan's visit Earth after picking up the signature of the newly invented warp drive. Did Vulcan's already have warp capabilities? If no, how did they get to Earth so fast? Did other races invent their own warp drives? If no, how did species such as the Borg obtain warp travel? It seems difficult for a non-warp society to overtake and assimilate technology from a warp society.
I always assumed Zefram Cochrane invented the warp drive which latter spread to other races but now I'm starting to think he only had invented it for humans and other races invented theirs independently.