Specialisation would therefore create and increase the opportunities for gains from trade. The more Oz goes fishing, the better he gets at it, so the less time it takes him to catch each fish. The more hooks Adam the reindeer hunter makes, the better he gets at it, so the less time he takes to make each one. So it pays Oz to spend his day fishing and buy his hooks off Adam by giving him some fish. And it pays Adam to spend his day making hooks and get his fish delivered by Oz.
