Genomic comparisons reveal biogeographic and anthropogenic impacts in the koala (Phascolarctos cinereus); a dietary-specialist species distributed across heterogeneous environments

The Australian koala is an iconic marsupial with specific dietary requirements distributed across heterogeneous environments, over a large geographic range. The distribution and genetic structure of koala populations has been heavily influenced by human actions, specifically habitat modification, hunting and translocation of koalas. There is currently limited information on population diversity and gene-flow at a species-wide scale, or with consideration to the potential impacts of local adaptation. Using species-wide sampling across heterogeneous environments, and high-density genome-wide markers (SNPs and PAVs), we show that most koala populations display levels of diversity comparable to other outbred species, except for those populations impacted by population reductions. Genetic clustering analysis and phylogenetic reconstruction reveals a lack of support for taxonomic classification of three koala sub-species, with only a single evolutionary significant unit supported. Furthermore...