Ancient DNA reveals complexity in the evolutionary history and taxonomy of the endangered Australian brush-tailed bettongs (Bettongia: Marsupialia: Macropodidae: Potoroinae)
MetadataShow full item record
© 2016 Springer Science+Business Media Dordrecht. The three surviving ‘brush-tailed’ bettong species—Bettongia gaimardi (Tasmania), B. tropica (Queensland) and B. penicillata (Western Australia), are all classified as threatened or endangered. These macropodids are prolific diggers and are recognised as important ‘ecosystem engineers’ that improve soil quality and increase seed germination success. However, a combination of introduced predators, habitat loss and disease has seen populations become increasingly fragmented and census numbers decline. Robust phylogenies are vital to conservation management, but the extent of extirpation and fragmentation in brush-tailed bettongs is such that a phylogeny based upon modern samples alone may provide a misleading picture of former connectivity, genetic diversity and species boundaries. Using ancient DNA isolated from fossil bones and museum skins, we genotyped two mitochondrial DNA (mtDNA) genes: cytochrome b (266 bp) and control region (356 bp). These ancient DNA data were combined with a pre-existing modern DNA data set on the historically broadly distributed brush-tailed bettongs (~300 samples total), to investigate their phylogenetic relationships. Molecular dating estimates the most recent common ancestor of these bettongs occurred c. 2.5 Ma (million years ago), which suggests that increasing aridity likely shaped their modern-day distribution. Analyses of the concatenated mtDNA sequences of all brush-tailed bettongs generated five distinct and well-supported clades including: a highly divergent Nullarbor form (Clade I), B. tropica (Clade II), B. penicillata (Clades III and V), and B. gaimardi (Clade IV). The generated phylogeny does not reflect current taxonomy and the question remains outstanding of whether the brush-tailed bettongs consisted of several species, or a single widespread species. The use of nuclear DNA markers (single nucleotide polymorphisms and/or short tandem repeats) will be needed to better inform decisions about historical connectivity and the appropriateness of ongoing conservation measures such as translocations and captive breeding.
Showing items related by title, author, creator and subject.
Effects of habitat fragmentation on population structure and long-distance gene flow in an endangered marsupial: The woyliePacioni, Carlo; Wayne, A.; Spencer, P. (2011)A deep understanding of population structures and of the relationships among populations is fundamental to guarantee adequate management of endangered species. We used a molecular approach (12 microsatellite loci and ...
Rong, J.; Bunce, Michael; Wayne, A.; Pacioni, C.; Ryan, U.; Irwin, P. (2012)The woylie or brush-tailed bettong (Bettongia penicillata) is a medium-sized native Australian marsupial that has undergone a dramatic decline in numbers in recent years. Trypanosome parasites have been identified in the ...
Pacioni, Carlo; Eden, P.; Reiss, A.; Ellis, T.; Knowles, G.; Wayne, A. (2015)© 2015 Ecological Society of Australia and Wiley Publishing Asia Pty Ltd. Disease is increasingly being recognised as a risk factor in declining wildlife populations around the globe. However, there are limited protocols ...