Abstract
Habitat fragmentation can act to cause reproductive isolation between conspecifics and undermine species’ persistence, though most studies have reported the genetic condition of populations that have already declined to a very small size. We examined genetic diversity within the vulnerable, declining koala (Phascolarctos cinereus) population in Southeast Queensland, Australia to determine the genetic impact of ongoing threatening processes. Five hundred and twelve koalas from ten Southeast Queensland Local Government Areas on the mainland and one island were genotyped at six polymorphic microsatellite loci. Based on Bayesian cluster analysis incorporating spatial data, the regional koala population was subdivided into six clusters, with location of major roads and rivers appearing to be consistent with being barriers to gene flow. The distribution of mtDNA control region haplotypes identified distinct coastal and inland clades suggesting that historically there was gene flow between koalas along the coast (though little interchange between coastal and inland animals). In contrast, koalas from the Koala Coast (Brisbane City, Logan City and Redland Shire) were shown by microsatellite analysis to be genetically distinct from adjacent areas. It is likely, therefore, that more recent reductions in population size and restricted gene flow through urbanisation have contributed to the genetic differentiation of koalas in the Koala Coast region.
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Acknowledgments
This project was funded by an Australian Research Council Linkage Grant, LP0455785. Thanks to Camryn Allen for providing samples from Burbank and Greg Simmons for sharing Gold Coast samples collected by Steve Phillips. David Pavlacky provided assistance with ArcGIS and Simon Blomberg assisted with performing statistical analyses. Thanks to staff of Queensland Parks and Wildlife Service Moggill Koala Hospital and Australian Wildlife Hospital for collecting samples. Thanks to Cynthia Riginos and the genetics discussion group and two anonymous reviewers for helpful feedback and suggestions.
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Lee, K.E., Seddon, J.M., Corley, S.W. et al. Genetic variation and structuring in the threatened koala populations of Southeast Queensland. Conserv Genet 11, 2091–2103 (2010). https://doi.org/10.1007/s10592-009-9987-9
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DOI: https://doi.org/10.1007/s10592-009-9987-9