Papua New Guinea (Tok Pisin: Papua Niugini) (PNG), officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands (the western portion of the island is a part of the Indonesian provinces of Papua and West Papua). It is located in the southwestern Pacific Ocean, in a region defined since the early 19th century as Melanesia. The capital is Port Moresby.

Papua New Guinea is one of the most culturally diverse countries on Earth, with over 850 indigenous languages and at least as many traditional societies, out of a population of just under seven million. It is also one of the most rural, as only 18% of its people live in urban centres. The country is one of the world's least explored, culturally and geographically, and many undiscovered species of plants and animals are thought to exist in the interior of Papua New Guinea.

The majority of the population live in traditional societies and practise subsistence-based agriculture. These societies and clans have some explicit acknowledgement within the nation's constitutional framework. The PNG Constitution (Preamble 5(4)) expresses the wish for "traditional villages and communities to remain as viable units of Papua New Guinean society", and for active steps to be taken in their preservation.

After being ruled by three external powers since 1884, Papua New Guinea gained its independence from Australia in 1975. It remains a Commonwealth realm of Her Majesty Elizabeth II, Queen of Papua New Guinea. Many people live in extreme poverty, with about one third of the population living on less than US$1.25 per day.

Human remains have been found which have been dated to about 50,000 BC although this is an estimate. These ancient inhabitants probably had their origins in Southeast Asia, themselves originating in Africa 50,000 to 70,000 years ago. New Guinea was one of the first landmasses after Africa and Eurasia to be populated by modern humans, with the first migration at approximately the same time as that of Australia.

Agriculture was independently developed in the New Guinea highlands around 7000 BC, making it one of the few areas of original plant domestication in the world. A major migration of Austronesian speaking peoples came to coastal regions roughly 500 BC, and this is correlated with the introduction of pottery, pigs, and certain fishing techniques. More recently, in the 18th century, the sweet potato entered New Guinea having been introduced to the Moluccas from South America by the locally dominant colonial power, Portugal. The far higher crop yields from sweet potato gardens radically transformed traditional agriculture; sweet potato largely supplanted the previous staple, taro, and gave rise to a significant increase in population in the highlands.

Although headhunting and cannibalism have been practically eradicated, in the past they occurred in many parts of the country. For example, in 1901, on Goaribari Island in the Gulf of Papua, a missionary, Harry Dauncey, found 10,000 skulls in the island’s Long Houses. According to the writer Marianna Torgovnick, "The most fully documented instances of cannibalism as a social institution come from New Guinea, where head-hunting and ritual cannibalism survived, in certain isolated areas, into the fifties, sixties, and seventies, and still leave traces within certain social groups."

Little was known in the West about the island until the nineteenth century, although Portuguese and Spanish explorers such as Dom Jorge de Meneses and Yñigo Ortiz de Retez respectively had encountered it as early as the sixteenth century. Traders from Southeast Asia had also been visiting New Guinea as long as 5,000 years ago collecting bird of paradise plumes. The country's dual name results from its complex administrative history before independence. The word papua is derived from pepuah, a Malay word describing the frizzy Melanesian hair, and "New Guinea" (Nueva Guinea) was the name coined by the Spanish explorer Yñigo Ortiz de Retez, who in 1545 noted the resemblance of the people to those he had earlier seen along the Guinea coast of Africa. The northern half of the country came into German hands in 1884 as German New Guinea.

During World War I, it was occupied by Australia, which had begun administering British New Guinea, the southern part, as the re-named Papua in 1904. After World War I, Australia was given a mandate to administer the former German New Guinea by the League of Nations. Papua, by contrast, was deemed to be an External Territory of the Australian Commonwealth, though as a matter of law it remained a British possession, an issue which had significance for the country's post-independence legal system. This difference in legal status meant that Papua and New Guinea had entirely separate administrations, both controlled by Australia.

The New Guinea campaign (1942–1945) was one of the major military campaigns of World War II. Approximately 216,000 Japanese, Australian and U.S. soldiers, sailors and airmen died during the New Guinea Campaign. The two territories were combined into the Territory of Papua and New Guinea after World War II, which later was simply referred to as "Papua New Guinea". However, certain statutes continued to have application only in one of the two territories, a matter considerably complicated today by the adjustment of the former boundary among contiguous provinces with respect to road access and language groups, so that such statutes apply on one side only of a boundary which no longer exists.

The administration of Papua became open to United Nations oversight and a peaceful independence from Australia occurred on September 16, 1975, and close ties remain (Australia remains the largest bilateral aid donor to Papua New Guinea). Papua New Guinea was admitted to membership in the United Nations on 10 October 1975.

A secessionist revolt in 1975–76 on Bougainville Island resulted in an eleventh-hour modification of the draft Constitution of Papua New Guinea to allow for Bougainville and the other eighteen districts to have quasi-federal status as provinces. The revolt recurred and claimed 20,000 lives from 1988 until it was resolved in 1997. Following the revolt, the autonomous Bougainville elected Joseph Kabui as president. He was succeeded by deputy John Tabinaman. who remained leader until the election of December 2008, with James Tanis emerging as the winner.

Anti-Chinese rioting, involving tens of thousands of people, broke out in May 2009. The initial spark for this was a fight between Chinese and Papua New Guinean workers at a nickel factory which was being built by a Chinese company; the underlying reason for the protest was a resentment against the number of small businesses being run by Chinese.

It is estimated that more than a thousand different cultural groups exist in Papua New Guinea. Because of this diversity, many different styles of cultural expression have emerged; each group has created its own expressive forms in art, dance, weaponry, costumes, singing, music, architecture and much more. Most of these different cultural groups have their own language. People typically live in villages that rely on subsistence farming. In some areas people hunt and collect wild plants (such as yam roots) to supplement their diets. Those who become skilled at hunting, farming and fishing earn a great deal of respect.

On the Sepik river, there is a tradition of wood carving, often in the form of plants or animals, representing ancestor spirits.

Sea shells are no longer the currency of Papua New Guinea, as they were in some regions – sea shells were abolished as currency in 1933. However, this heritage is still present in local customs; in some cultures, to get a bride, a groom must bring a certain number of golden-edged clam shells as a bride price. In other regions, the bride price is paid in lengths of shell money, pigs, cassowaries or cash. Elsewhere, it is brides who traditionally pay a dowry.

People of the highlands engage in colourful local rituals that are called "sing sings". They paint themselves and dress up with feathers, pearls and animal skins to represent birds, trees or mountain spirits. Sometimes an important event, such as a legendary battle, is enacted at such a musical festival.

Sport

Sport is an important part of Papua New Guinean culture and rugby league is by far the most popular sport. In a nation where communities are far apart and many people live at a minimal subsistence level, rugby league has been described as a replacement for tribal warfare as a way of explaining the local enthusiasm for the game (a matter of life and death). Many Papua New Guineans have become instant celebrities by representing their country or playing in an overseas professional league. Even Australian rugby league players who have played in the annual (Australian) State of Origin clash, which is celebrated feverishly every year in PNG, are among the most well known people throughout the nation.

State of Origin is a highlight of the year for most Papua New Guineans, although the support is so passionate that many people have died over the years in violent clashes supporting their team. The Papua New Guinea national rugby league team usually plays against the Australian Prime Minister's XIII (a selection of NRL players) each year, normally in Port Moresby.

Other major sports which have a part in the Papua New Guinea sporting landscape are Aussie rules, soccer (football), rugby union and, in eastern Papua, cricket. Its football team ranked worst on FIFA ranking of all countries.

At 462,840 km (178,704 sq mi), Papua New Guinea is the world's fifty-fourth largest country. Including all its islands, it lies between latitudes 0° and 12°S, and longitudes 140° and 160°E.

The country's geography is diverse and, in places, extremely rugged. A spine of mountains, the New Guinea Highlands, runs the length of the island of New Guinea, forming a populous highlands region mostly covered with tropical rainforest. Dense rainforests can be found in the lowland and coastal areas as well as very large wetland areas surrounding the Sepik and Fly rivers. This terrain has made it difficult for the country to develop transportation infrastructure. In some areas, airplanes are the only mode of transport. The highest peak is Mount Wilhelm at 4,509 metres (14,793 ft). Papua New Guinea is surrounded by coral reefs which are under close watch to preserve them.

The country is situated on the Pacific Ring of Fire, at the point of collision of several tectonic plates. There are a number of active volcanoes, and eruptions are frequent. Earthquakes are relatively common, sometimes accompanied by tsunamis.

The mainland of the country is the eastern half of New Guinea island, where the largest towns are also located, including the capital Port Moresby and Lae; other major islands within Papua New Guinea include New Ireland, New Britain, Manus and Bougainville.

Papua New Guinea is one of the few regions close to the equator that experience snowfall, which occurs in the most elevated parts of the mainland.

Ecology

Papua New Guinea is part of the Australasia ecozone, which also includes Australia, New Zealand, eastern Indonesia, and several Pacific island groups, including the Solomon Islands and Vanuatu.

Geologically, the island of New Guinea is a northern extension of the Indo-Australian tectonic plate, forming part of a single landmass Australia-New Guinea (also called Sahul or Meganesia). It is connected to the Australian segment by a shallow continental shelf across the Torres Strait, which in former ages had lain exposed as a land bridge – particularly during ice ages when sea levels were lower than at present.

Consequently, many species of birds and mammals found on New Guinea have close genetic links with corresponding species found in Australia. One notable feature in common for the two landmasses is the existence of several species of marsupial mammals, including some kangaroos and possums, which are not found elsewhere. Many of the other islands within PNG territory, including New Britain, New Ireland, Bougainville, the Admiralty Islands, the Trobriand Islands, and the Louisiade Archipelago, were never linked to New Guinea by land bridges, and they have their own flora and fauna, in particular they lack many of the land mammals and flightless birds that are common to New Guinea and Australia.

Australia and New Guinea are portions of the ancient supercontinent of Gondwana, which started to break into smaller continents in the Cretaceous era, 65-130 million years ago. Australia finally broke free from Antarctica about 45 million years ago. All the Australasian lands are home to the Antarctic flora, descended from the flora of southern Gondwana, including the coniferous podocarps and Araucaria pines, and the broadleafed southern beech (Nothofagus). These plant families are still present in Papua New Guinea.

As the Indo-Australian Plate (which includes landmasses of India, Australia, and the Indian Ocean floor in between) drifts north, it collides with the Eurasian Plate, and the collision of the two plates pushed up the Himalayas, the Indonesian islands, and New Guinea's Central Range. The Central Range is much younger and higher than the mountains of Australia, so high that it is home to rare equatorial glaciers. New Guinea is part of the humid tropics, and many Indomalayan rainforest plants spread across the narrow straits from Asia, mixing together with the old Australian and Antarctic floras.

PNG includes a number of terrestrial ecoregions:

At current rates of deforestation, more than half of the country's forests could be lost or seriously degraded by 2021, according to a new satellite study of the region. Nearly one quarter of Papua New Guinea's rainforests were damaged or destroyed between 1972 and 2002.