Soon after reaching the Philippines, Austronesians colonized the Northern Mariana Islands by 1500 BCE and Palau and Yap by 1000 BCE, becoming the first humans to reach Remote Oceania. Another important migration branch was by the Lapita culture, which rapidly spread into the islands off the coast of northern New Guinea and into the Solomon Islands and other parts of Island Melanesia by 1200 BCE. They reached the Polynesian islands of Samoa and Tonga by around 900 to 800 BCE. This remained the furthest extent of the Austronesian expansion into Polynesia until around 700 CE when there was another surge of island colonization. They reached the Cook Islands, Tahiti, and the Marquesas by 700 CE; Hawaii by 900 CE; Rapa Nui by 1000 CE; and New Zealand by 1200 CE. There is also putative evidence, based in the spread of the sweet potato, that Austronesians may have reached South America from Polynesia where they traded with American Indians.