New Guinea's lowland tropical forests are vast and are largely connected. Animal species living in lowland forests are often common and continuously distributed throughout these lowlands (in essentially a ring around the central mountain ranges of New Guinea). However, lowland forest species often show tremendous amounts of genetic or phenotypic variation. We hypothesize that this variation is due largely to geographic or geologic history, and we propose several testable hypotheses that might account for this variation (including specific historical events or dispersal barriers, habitat differences, and multiple competing evolutionary processes). We will use analyses of mitochondrial and nuclear DNA sequence variation from six common, widespread focal bird species to determine which evolutionary models best explain the pattern and sources of variation in New Guinea's lowland forests.
This study will be the first to employ modern genetic data and analyses to the phylogeography of lowland New Guinea. We expect these data to identify lowland biogeographic provinces heretofore unrecognized, and it will therefore have important implications for conservation planning. Our biological evidence will provide independent estimates of the timing of geologic events. In addition, this study will employ and critically examine new phylogeographic analyses that are still maturing. We hope to critically examine the assumptions and uses of these tests in complex geographical regions, such as New Guinea. Finally, the project will train 6-8 New Guinea biology students who will receive practical experience in field techniques, systematics, and evolutionary biology.
