Ricky, really?  Don't you know what happens to any organism that is separated from others of the same race for 500 years?  They lose their immunity over time to fight deceases that they used to have the ability to fight off.  No one then knew what we know now.  It was not some kind of premeditation that Capt. Cook reintroduced deceases into the Polynesian invaders here.  And, do you really believe that no one up to now would not have come along and found these islands? After all, the Polynesians were also not the first either.
You are calling them a "tribe".  I know that a large portion of the Polynesian community here would take offense to being called a tribe, or anything else to do with Washington D.C. having control over them through the Bur. of Indian Affairs.
This is the year 2016, soon to be 2017.  Whatever dead people did to dead people has little weight for those living today. 
We are all Natives of the Planet Earth.  
It's time that everyone stands on their own two feet.