As a geographical and cultural region, Southern New Guinea stretches from the Fly River in the east to the Maro river in the west. It takes in the Trans-Fly district of Western Province, PNG, plus adjacent parts of Indonesia around the district capital of Merauke. Our project will be confined to the PNG side.
The region stretches about 300 km from west to east and 150 km from north to south. Geographically it is like a broken-off piece of northern Australia pasted onto southern New Guinea: a realm of eucalyptus and melaleuca savannah, anthills, wallabies and bandicoots, alternating with dense rainforest in which swidden yam cultivation is practiced. It has had a dramatic geomorphological past: in the last 10,000 years it has variously been joined on to Australia, cut off by rising seas, formed a separate large island, and then been rebuilt by progradation with sediment brought south by the giant Fly River.
This dynamic geo-morphological history is one likely cause of the regions extreme linguistic diversity. A prima facie account would see the inner language families (Morehead/Maro, Marori and Pahoturi rivers and Eastern Trans-Fly) as representing early settlers, likely entering the region from various directions as it was built up.