Effects of quaternary climate change and rainforest diversity: insights from spatial analyses of species and genes in Australia’s wet tropics

Abstract

Biogeographic patterns are often used to generate hypotheses concerning the evolutionary and ecological processes that structure patterns of species distribution and diversity. However, biogeographic patterns alone are often insufficient to infer historical processes. In this chapter we illustrate how analyses of molecular population genetic variation combined with spatial analyses of species distribution and diversity can provide strong inference of historical processes shaping current patterns of diversity at several hierarchical levels. The strengths of these analyses are multiplied when independent paleoecological data exist. We illustrate this approach using endemic vertebrate species from the Wet Tropics of Australia. We demonstrate that Quaternary climatic fluctuations, and associated changes in rainforest distribution and extent, have left an identifiable footprint on local, landscape, and regional patterns of genetic diversity, species distribution and diversity, and community composition.