Over about 25,000 years, these people, called the Polynesians, eventually colonized the islands of the south and western Pacific, from New Guinea in the west to Fiji and Samoa in the middle. Then they moved onward to Tahiti and finally Easter Island in the eastern south Pacific.bout 30,000 years ago, human cultures along the western coastline of the Pacific Ocean -- in the area between what is now Australia and China -- started to migrate eastward across the great expanse of the Pacific Ocean.