Significant patterns of population genetic structure and limited gene flow in a threatened macropodid marsupial despite continuous habitat in southeast Queensland, Australia

Many endangered species worldwide are found in remnant populations, often within fragmented landscapes. However, when possible, an understanding of the natural extent of population structure and dispersal behaviour of threatened species would assist in their conservation and management. The brush-tailed rock-wallaby (Petrogale penicillata), a once abundant and widespread rock-wallaby species across southeastern Australia, has become nearly extinct across much of the southern part of its range. However, the northern part of the species' range still sustains many small colonies closely distributed across suitable habitat, providing a rare opportunity to investigate the natural population dynamics of a listed threatened species. We used 12 microsatellite markers to investigate genetic diversity, population structure and gene flow among brush-tailed rock-wallaby colonies within and among two valley regions with continuous habitat in southeast Queensland. We documented high and signifcant levels of population genetic structure between rock-wallaby colonies embedded in continuous escarpment habitat and forest. We found a strong and significant pattern of isolation-by-distance among colonies indicating restricted gene flow over a small geographic scale (< 10 km) and conclude that gene flow is more likely limited by intrinsic factors rather than environmental factors. In addition, we provide evidence that genetic diversity was significantly lower in colonies located in a more isolated valley region compared to colonies located in a valley region surrounded by continuous habitat. These findings shed light on the processes that have resulted in the endangered status of rock-wallaby species in Australia and they have strong implications for the conservation and management of both the remaining 'connected' brush-tailed rock-wallaby colonies in the northern parts of the species' range and the remnant endangered populations in the south.

The politics of Australian society: Political issues for the new century

The aim of this book is to assist those who want to understand and analyse social, political and economic issues. In this project we have drawn upon the resources of political science, which typically examines the interaction between political ideas, institutions and policies in its attempt to make sense of the society in which we live. The perspectives offered by political science are evident in the structure of contributions to the volume. The organising framework we have adopted emphasises the importance of political ideas in shaping the way we comprehend political issues; the centrality of political institutions in influencing the possibilities for and limits on politics; and how present and past policies determine the context and direction of the solutions to political problems. This second edition expands upon out original brief. Where we have retained certain topics, the chapters have all been revised and updated. There are also a number of new chapters in each section that deal with significant political doctrines, institutions and policies.