 The Austronesians that spread westward through Maritime Southeast Asia also colonized parts of mainland Southeast Asia.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.