Oceania[note 1] is a geographical term associated with a variety of islands inside the Pacific Ocean, mostly so that these island countries can have a 'continent' associated with them. Oceania does have an actual continent in it: Australia, as distinct from the country of Australia. The continent of Australia includes the island of New Guinea and smaller nearby islands (such as Tasmania). The continent of Australia is defined by the Sahul Shelf, which was once a single land mass when ocean levels were lower. There is also the 'semicontinent' of Zealandia. Everything else is a continental island (such as New Britain), a volcanic island chain (such as Hawaii), an atoll (such as Tarawa), or a seamount. This region is associated with the very geologically active Pacific Plate, which subducts under the Mariana Plate and the Australian plate to form many of these islands; others were created by geological hot spots where lava rises from far underneath the surface in the middle of the Pacific Plate. These islands have until relatively recently been isolated from the rest of the world. In fact, Australia, New Guinea and nearby islands are the only parts of Oceania to have any native land mammals besides bats, and even then they are rodents, marsupials and monotremes[1] as opposed to the placentals that dominate every other continent besides Antarctica. This region of the world is probably the most vulnerable to environmental issues, from the invasive species that are a threat to the native flora and fauna to climate change, which threatens to leave many of the islands underwater.
Besides Australia/New Guinea, which was first settled at least 48,000 years ago, most of Oceania was only settled by humans relatively recently, with even New Zealand only being inhabited somewhere between 1200 and 1300 CE. Yes, during the entire time the Roman Empire rose and fell, there were no humans living in New Zealand. Today, there are around 43 million people living in the region, or only about 0.5% of the world's population. As they were grouped together due to geography rather than anything else, this is understandably a very diverse region of the globe,[note 2] however, there are three things that most of the islands of this region have in common.
The history of this region cannot be disconnected from its colonial past, with no part of it remaining untouched. The first European visitors were circumnavigators such as Ferdinand Magellan. Magellan's expedition led to Spain taking Guam and the Northern Mariana Islands. Missionaries were sent all over these islands to spread Christianity; violent incidents involving them would lead to their home countries intervening. However, it wouldn't be until the main age of imperialism in the 19th century when colonialism would take this region by full force. France took over a number of islands between 1840 and 1880, while the Germans, Americans, and British would compete over much of Polynesia and Micronesia, and even the Dutch would get involved with New Guinea. The role of corporations in colonialization is also important; Hawaii was infamously taken over by the Dole Fruit Company while competing German and British corporations led to those countries being involved in Samoa. During WWI, Japan took Germany's colonies in the North Pacific while Britain would take the colonies in the South. The low point was probably WWII, where the Japanese, fueled by extreme nationalism, tried conquering the entire Pacific for themselves; this left millions dead. The colonial overlords largely used up a lot of the islands' few natural resources, especially the phosphate. To this day, many islands are still ruled by countries on the other side of the world, and even the ones that aren't are still heavily dependent on foreign aid. The situation in West Papua, which is ruled by Indonesia, is the most violent example of colonialism in this region that is still occurring today. In recent years, China has started to make inroads in this region as well.[2]
Oceania can be considered the Bible Belt of the world. Nearly every country has a percentage of Christians from the mid 80s to the 90s, with Polynesian countries approaching 100% Christian. And these aren't just ordinary denominations: the LDS has a considerable presence in Tonga and Samoa, and most countries also have Seventh-day Adventist populations. Although not Christian, the Baha'i faith has taken a hold on most islands. Roman Catholicism is extremely dominant in regions that were dominated by France or Spain, and evangelical Protestantism is dominant elsewhere. There are exceptions: Fiji has a significant Hindu population, and the Marianas have Buddhists due to immigration. Vanuatu is known for its cargo cults, while of course Australia and New Zealand have significant nonreligious populations as well as strong Church of England influence. But overall, this is one of the most aggressively Christian parts of the world.
With the exceptions of Australia, New Zealand, and Hawaii (and even in those three, the indigenous populations are still poor) and the semi-exception of Fiji (which is doing okay for itself as it has a decent amount of natural resources, although it's still not very impressive), Oceania is the poorest region of the world. This is because most of the islands have few natural resources. For the many of the smaller island nations, bird poop (a.k.a. phosphate), has been largely exhausted. Many of the islands are so remote and undeveloped that they can't make much money out of tourism or even being a tax haven. This makes these countries entirely dependent on foreign aid and having no power outside their own borders. This is why many have not broken away from their colonial overlords. Some of the countries have come up with creative ways to earn money. For example, Tuvalu cleverly registered its ccTLD as ".tv",[note 3] while Niue releases commemorative coins every year that have images of everything from Pokémon[3] to Star Wars[4] engraved on them; these coins are big with the collectors. However, most Oceanian nations are still extremely poor, which means that they will have few resources to deal with the impending threat that climate change poses to them.
Oceania is usually split into three or four somewhat arbitrary regions that help to better understand the ethnic and cultural history of the area. These regions are not perfect, as there is evidence of some cross-migration and interbreeding among the three main ethnic groups that the area is known for, however, they are useful for what they are.
This is probably the most arbitrary out of all of the subdivisions. It just contains Australia and New Zealand, which are just together because a bunch of white men thought they should be, as the indigenous people of Australia and New Zealand share very little in common culturally and ethnically. After all, why include Australia or New Zealand with any of those Third World countries? This haphazard categorization leaves it only useful as a category of the political reality of the present day and not for understanding the islands' culture and history.
This includes the islands directly to the north and northwest of Australia. This term came from the dark skin of the inhabitants of the islands; as you can probably guess, this was the subject of a lot of racial pseudoscience back in the day. Melanesians are partially descended from one of the first populations of Homo sapiens to leave Africa, dubbed "XOoA", which left Africa 120,000 years ago, and comprises about 2% of their ancestry. The majority of their ancestry, however, is similar to that of other non-Africans, from the same major migration out of Africa that occurred 50,000 to 60,000 years ago. They first arrived in what is today New Guinea and Australia (which at the time was one landmass, thanks to the ice age) over 48,000 years ago. The other islands in the region weren't settled until much later, the Lapita culture is believed to have settled them first with Melanesians arriving later. Notable regions of Melanesia include:
Micronesia consists of the islands that are north of Melanesia. They were settled by an Austronesian people likely from the Philippines, which became the ancestors of both the Micronesians and Polynesians. They first settled the Marianas around 1500 BCE and spread outward from there. Notable regions include:
Think of a triangle with New Zealand at one corner, Hawaii at another, and Rapa Nui (a.k.a. Easter Island) at the third. Polynesia is everything that is inside the triangle and is the largest of the regions. The Polynesians were incredibly skilled navigators, as evidenced by their ability to reach remote islands; some recent genetic evidence suggests that they may have even visited the Americas before Christopher Columbus.[5] Notable regions include: