"Family relationships" between islands ?

In the future, we would like to try to develop a concept « Family relationship » between the small islands used for conservation purposes in the Framework of the Polymotu project. 

For instance, once a coconut variety is isolated in a small island, it becomes quite cheap and easy to transfer this variety to another small island, possibly for instance less endangered by climate change, for safety duplication and use. 

So, both from the biodiversity and the allegorical points of view, the first island will become a kind of the “mother” of the second one. We are searching for Polynesian or islanders traditions using such a concept of family relationship between islands, but up to now we did not find such legends. If you find, please tell me...