https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47630 Acridotheres tristis). Methods: We used a reduced genome representation method (DArTseq) to generate thousands of single nucleotide polymorphism markers in 462 common mynas. We then applied population genomic techniques to identify the common myna's population attributes such as gene flow, genetic diversity, and effective dispersal, all of which are critical for understanding geographical range expansion of pest species. Results: We found significant genetic structuring across the common myna's Australian distribution, indicating limited levels of effective dispersal amongst the populations founded from historic introductions in the 19th century. The historic introduction points were found to be genetically distinct, such that in the region on the invasion front where admixture did occur, myna populations exhibited higher genetic diversity than in the source populations. Significant isolation by distance was evident amongst populations derived from the same founding population, with genetic diversity decreasing moving away from the point of colonization, and in general, higher levels of gene flow from source to front than vice versa. Main conclusions: This study indicates that despite a 150-year colonization history of mynas in Australia, contemporary genetic structure still largely reflects human-mediated dispersal. However, expanding populations are now connecting and the consequent increased genetic diversity may improve evolutionary potential. These results suggest that more management focus should be directed towards the invasion fronts, rather than the large, historic source populations.]]> Tue 24 Jan 2023 14:16:33 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:2405 Sat 24 Mar 2018 08:29:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:30556 Athrotaxis cupressoides D. Don (461 samples from 20 populations) and Diselma archeri Hook.f. (576 samples from 23 populations, 16 of which were for sites sampled for A. cupressoides), were genotyped using eight and nine EST nuclear microsatellites respectively. Genetic diversity and structure was compared between the two species and the factors underlying genetic patterns in both species were investigated by examining isolation by distance, correlations with Last Glacial Maximum modelled distributions and the fossil record, and a fire history index of the sampled stands. Results: The range-wide genetic structure of the two species was similar (F_st = 0.09 and F’_st = 0.21 for A. cupressoides versus D. archeri; F_st = 0.06 and F’_st = 0.24), and there were significant correlations between species for population-based expected heterozygosity, allelic richness, private allelic richness and pairwise genetic divergences. Furthermore, genetic diversity metrics decreased significantly with an index of fire history. Given fossil evidence and modelling evidence that both species occurred near their current ranges during the last glaciation and a lack of evidence for isolation by distance in either species, the plausible explanation for the patterns of diversity is genetic decline resulting from repeated Holocene fires. Main conclusions: Our study suggests that fire can have substantial impacts on genetic structure and diversity of plant species, particularly those without fire-tolerant traits, and that any increases in fire resulting from climate change may impose substantial threats to such species. In Tasmania, the observed increase in dry lightning in recent years, combined with periods of abnormally dry conditions, may therefore further degrade the range and genetic diversity of fire-intolerant palaeoendemic species.]]> Sat 24 Mar 2018 07:27:09 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3490 Sat 24 Mar 2018 07:20:34 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3429 Sat 24 Mar 2018 07:20:25 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51895 Fri 22 Sep 2023 09:29:03 AEST ]]>