The greater Pacific region, traditionally called Oceania, consists of three cultural areas: Melanesia, Micronesia, and Polynesia. Melanesia, in the southwest Pacific, contains the large islands of New Guinea, the Solomons, Vanuatu, and New Caledonia. Micronesia, the area north of Melanesia, consists primarily of small scattered islands. Polynesia is the central Pacific area in the great triangle defined by Hawaii, Easter Island, and New Zealand. Before the arrival of Europeans, the islands in the two largest cultural areas, Polynesia and Micronesia, together contained a population estimated at 700,000.

Speculation on the origin of these Pacific islanders began as soon as outsiders encountered them, in the absence of solid linguistic, archaeological, and biological data, many fanciful and mutually exclusive theories were devised. Pacific islanders are variously thought to have come from North America, South America, Egypt, Israel, and India, as well as Southeast Asia. Many older theories implicitly deprecated the navigational abilities and overall cultural creativity of the Pacific islanders. For example, British anthropologists G. Elliot Smith and W. J. Perry assumed that only Egyptians would have been skilled enough to navigate and colonize the Pacific.They inferred that the Egyptians even crossed the Pacific to found the great civilizations of the New World (North and South America). In 1947 Norwegian adventurer Thor Heyerdahl drifted on a balsa-log raft westward with the winds and currents across the Pacific from South America to prove his theory that Pacific islanders were Native Americans (also called American Indians). Later Heyerdahl suggested that the Pacific was peopled by three migrations: by Native Americans from the Pacific Northwest of North America drifting to Hawaii, by Peruvians drifting to Easter Island, and by Melanesians. In 1969 he crossed the Atlantic in an Egyptian-style reed boat to prove Egyptian influences in the Americas. Contrary to these theorists, the overwhelming evidence of physical anthropology, linguistics, and archaeology shows that the Pacific islanders came from Southeast Asia and were skilled enough as navigators to sail against the prevailing winds and currents.

The basic cultural requirements for the successful colonization of the Pacific islands include the appropriate boat-building, sailing, and navigation skills to get to the islands in the first place, domesticated plants and gardening skills suited to often marginal conditions, and a varied inventory of fishing implements and techniques. It is now generally believed that these prerequisites originated with peoples speaking Austronesian languages (a group of several hundred related languages) and began to emerge in Southeast Asia by about 5000 B.C.E. The culture of that time, based on archaeology and linguistic reconstruction, is assumed to have had a broad inventory of cultivated plants including taro, yarns, banana, sugarcane, breadfruit, coconut, sago, and rice. Just as important, the culture also possessed the basic foundation for an effective maritime adaptation, including outrigger canoes and a variety of fishing techniques that could be effective for overseas voyaging.

Contrary to the arguments of some that much of the pacific was settled by Polynesians accidentally marooned after being lost and adrift, it seems reasonable that this feat was accomplished by deliberate colonization expeditions that set out fully stocked with food and domesticated plants and animals. Detailed studies of the winds and currents using computer simulations suggest that drifting canoes would have been a most unlikely means of colonizing the Pacific. These expeditions were likely driven by population growth and political dynamics on the home islands, as well as the challenge and excitement of exploring unknown waters.

Because all Polynesians, Micronesians, and many Melanesians speak Austronesian languages and grow crops derived from Southeast Asia, all these peoples most certainly derived from that region and not the New World or elsewhere. The undisputed pre-Columbian presence in Oceania of the sweet potato, which is a New World domesticate, has sometimes been used to support Heyerdahl’s “American Indians in the Pacific” theories. However, this is one plant out of a long list of Southeast Asian domesticates. As Patrick Kirch, an American anthropologist, points out, rather than being brought by rafting South Americans, sweet potatoes might just have easily been brought back by returning Polynesian navigators who could have reached the west coast of South America.

广义的太平洋地区，传统上被称作大洋洲，由三块文化区域组成：美拉尼西亚，密克罗尼西亚和波利尼西亚。美拉尼西亚在西南太平洋，包含了新几内亚岛、所罗门、瓦努阿图和新喀里多尼亚的广大岛屿。密克罗尼西亚在美拉尼西亚的北边，主要由一些分散的岛屿组成。波利尼西亚是太平洋中心地区，位于由夏威夷、复活节群岛和新西兰的三大岛屿组成的三角区域中。在欧洲人到来之前，最大的波利尼西亚和密克罗尼西亚岛屿群一共有差不多70万人口。 对于太平洋群岛居民起源的思索开始于外来者和岛民们接触的最初，由于缺乏可靠的语言学、考古学和生物学资料，出现了很多奇异并且互斥的理论。之前太平洋岛民曾被认为来自北美洲、南美洲、埃及、以色列、印度以及东南亚。许多古老的理论含蓄地贬低了太平洋群岛居民的航海能力和综合文化创造力。比如说，英国人类学家G. Elliot Smith 和W. J. Perry认为只有埃及人才能熟练地航海和统治太平洋。他们推断埃及人甚至曾经穿越过太平洋去寻找新世界的文明（北美洲和南美洲）。1947年，挪威探险家Thor Heyerdahl为了证明他的太平洋群岛居民是美国本土居民（也被称作美国印第安人）的理论，用一只带有标志的轻质木筏，借助风力和水流从南美洲漂流过了太平洋。后来Heyerdahl表明太平洋人来自三个移民群体：从北美洲西北部太平洋地区漂流到夏威夷的美国本土居民，从秘鲁去往复活节岛的漂流者，还有美拉尼西亚人。1969年，他驾驶一条埃及样式的芦苇船穿过大西洋，证明埃及人在美洲的影响。与这些理论相矛盾的是，有关物理人类学、语言学和考古学的权威证据表明，太平洋岛居民来自东南亚，并且他们有足够的能力来逆着风和洋流航行。 成功地将太平洋群岛殖民地化需要的基础文化条件包括：适当的造船、航行和航海技术以首先到达岛屿；适应贫瘠条件的驯化植物和园艺技术；各种各样的捕鱼器具和技术。现在普遍认为这些先决条件是那些说南岛语（一个有几百种亲属语种的语系）的人所带来的，他们公元前5 000年前就出现在东南亚。通过考古学和语言学的重建发现，那个时候的文明拥有广泛的植物储存，包括芋头、纱、香蕉、甘蔗、面包果、椰子、西米和稻米。同样重要的是，当时的社会也具备适应海洋的基础，包括桅杆船和各种各样有利于越洋航行的捕鱼技术。 与那个太平洋人很多都是波利尼西亚人偶然迷失并漂流而定居下来的说法相反的是，这些功绩是通过有意的殖民远征来实现的，他们那些准备周详，出发时满载食物、已培育好的植物和以驯化的动物。通过电脑模拟对风向和洋流进行的详细研究表明，船只漂流是最不可能的殖民太平洋的途径。远征可能是由本土的人口增长、政治动荡以及探索未知水域的挑战和兴奋所驱动的。因为所有的波利尼西亚人、密克罗尼西亚人和很多美拉尼西亚人说南岛语，种植的庄稼起源于东南亚，所以所有的这些人最有可能来自那个地方，而不是新世界或者其他地方。甘薯，一种新世界的品种，在哥伦比亚发现美洲大陆前它就在大洋洲的出现，这是无可置疑的，这有时候被用来证明Heyerdahl的太平洋岛民是美国印第安人的理论。然而，这是一种在东南亚培育的植物的长名单之外的植物。正如美国人类学家Patrick Kirch所指出的，比起从南美漂流过来，甘薯更容易被那些到过南美的玻利尼西亚返航者携带来。