The Island Ecology Theory: It is suggested in "island theory" that if an island had once been connected to a continental land mass or is not far from such a land mass, then migration of animals back and forth should be relatively easy, so that the number of animal species will be more abundant.
島嶼理論中指出，大海中的島嶼若曾和陸塊相連或離陸塊較近，彼此間動物遷徙交往容易，動物種類也就比較豐富。