No one knows exactly when man first set foot in PNG, but evidence of his early presence has been found at a number of locations. In New Ireland, stone tools indicate human habitation more than 30,000 years old. On the Huon Peninsula, axes excavated from volcanic ash attest a civilisation that reaches back a further 10,000 years.
At Kuk, just outside Mount Hagen, a recently discovered drainage and mounding system, for both wet and dry cultivation, bears witness to the sophisticated agricultural communities that must have been spread all across the highlands thousands of years before their European counterparts took to cultivating the land. Archeological investigations indicate that a constant flow of hardy, adaptable peoples have streamed into Papua New Guinea from various parts of Asia and that the complex process of displacement and assimilation have led to exceptional diversity in all areas of art and culture.
In the Eastern Highlands there is cave art, stone artifacts and large-scale terracing of hill slopes for agricultural gardening, dating back tens of thousands of years. In Enga and the Southern Highlands, stone mortars and pestles have been unearthed, probably used for crushing and powdering nuts. Coastal civilisations at Balof Cave and on New Ireland are more recent. Lapita pottery has been found on Mussau Island, New Ireland and Manus Province. However, the most obvious difference between the growth of civilisation in Papua New Guinea and that in many other parts of the world is that the former never developed into city-states. Paradoxically, the sophistication of agricultural techinques may have prohibited the growth of such intense masses of population since virtually none of the crops could be stored or transported over great distances. The result was highly developed but small and local agricultural units, optimising the cultivation of their own specific environments.
Many of these early agricultural practices may have been disappeared when the sweet potato was first introduced into the country. The ‘kaukau’ or sweet potato soon became a crucial part of the staple diet in the highland valley communities where it was readily adaptable to the temperate climate. By the time the Europeans first penetrated into the Highlands in the 1930s, the thriving population of that region was close to a million. Like the ancient cultures of Central and South America, the Papua New Guineans did not have the wheel. Nor did they have looms. But excavations reveal that they had a rich material culture. Chinese glass beads and the remains of bronze drums on Lou Island are testament to international trade links over 2,000 years old. Obsidian tools carved in Talasea in West New Britain in 1500 BC have been found nearly 4,000 kilometres away in Fiji. There were complex trading networks around the coast and between the coastal and highland regions. Often the goods travel led circuitous routes to their destinations since the tribes would only trade with their immediate neighbours. Valuable commodities such as salt, obsidian, shells, oil, pigments, pottery and stone were traded around the country.