Unit+5-+Background+of+Oceania

__:) Some intresting facts of Oceania ;)__ · The Pacific Ocean makes up 1/3 of the entire earth! · There are 25,000 islands in the pacific ocea · There are 400 active volcanoes in the region · Many earthquakes as well!

BACKGROUND: The human history of Oceania comprises two extremes: the initial colonizations of Near Oceania, one of the oldest out-of-Africa migrations, and of Remote Oceania, the most recent expansion into unoccupied territories. Genetic studies, mostly using uniparentally inherited DNA, have shed some light on human origins in Oceania, particularly indicating that Polynesians are of mixed East Asian and Near Oceanian ancestry. Here, we use ∼1 million single nucleotide polymorphisms (SNPs) to investigate the demographic history of Oceania in a more detailed manner. RESULTS: We developed a new approach to account for SNP ascertainment bias, used approximate Bayesian computation simulations to choose the best-fitting model of population history, and estimated demographic parameters. We find that the ancestors of Near Oceanians diverged from ancestral Eurasians ∼27 thousand years ago (kya), suggesting separate initial occupations of both territories. The genetic admixture in Polynesian history between East Asians (∼87%) and Near Oceanians (∼13%) occurred ∼3 kya, prior to the colonization of Polynesia. Fijians are of Polynesian (∼65%) and additional Near Oceanian (∼35%) ancestry not found in Polynesians, with this admixture occurring considerably after the initial settlement of Remote Oceania. Our data support a greater contribution of East Asian women than men in the admixture history of Remote Oceania and highlight population substructure in Polynesia and New Guinea. CONCLUSIONS: Despite the inherent ascertainment bias, genome-wide SNP data provide new insights into the genetic history of Oceana. Our approach to correct for ascertainment bias and obtain reliable inferences concerning demographic history should prove useful in other such studies. Copyright © 2010 Elsevier Ltd. All rights reserved.

AMERICAN SAMOA Migrants from Southeast Asia arrived in the Samoan islands more than 2,000 years ago and from there settled the rest of Polynesia further to the east. Contact with Europeans began in the early 1700s but did not intensify until the arrival of English missionaries and traders in the 1830s. At the turn of the 20th century, the Samoan islands were split into two sections. The eastern islands became territories of the United States in 1904 and today are known as American Samoa. The western islands became known as Western Samoa (now just Samoa), passing from German control to New Zealand in 1914. COOK ISLANDS Named after Captain Cook, who sighted them in 1770, the islands became a British protectorate in 1888. By 1900, administrative control was transferred to New Zealand; in 1965 residents chose self-government in free association with New Zealand. The emigration of skilled workers to New Zealand and government deficits are continuing problems. FIJI Melanesian and Polynesian peoples settled the Fijian islands some 3,500 years ago. European traders and missionaries arrived in the first half of the 19th century, and the resulting disruption led to increasingly serious wars among the native Fijian confederacies. One Ratu (chief), Cakobau, gained limited control over the western islands by the 1850s, but the continuing unrest led him and a convention of chiefs to cede Fiji unconditionally to the British in 1874 __Key__ green-oceania

microocana The ancestors of the Micronesians settled the Caroline Islands over 4,000 years ago. A decentralized chieftain-based system eventually evolved into a more centralized economic and religious empire centered on Yap. European explorers -- first the Portuguese in search of the Spice Islands (Indonesia) and then the Spanish -- reached the Carolines in the 16th century, with the Spanish establishing sovereignty. The current FSM passed to German control in 1899, then to the Japanese in 1914, and finally to the U.S. under UN auspices in 1947 as part of the Trust Territory of the Pacific Islands.

microocana The ancestors of the Micronesians settled the Caroline Islands over 4,000 years ago. A decentralized chieftain-based system eventually evolved into a more centralized economic and religious empire centered on Yap. European explorers -- first the Portuguese in search of the Spice Islands (Indonesia) and then the Spanish -- reached the Carolines in the 16th century, with the Spanish establishing sovereignty. The current FSM passed to German control in 1899, then to the Japanese in 1914, and finally to the U.S. under UN auspices in 1947 as part of the Trust Territory of the Pacific Islands.