Disentangling the Genetic Relationships of Three Closely Related Bandicoot Species across Southern and Western Australia

Rujiporn Thavornkanlapachai,Margaret Byrne,Esther Levy,Kym Ottewell,Steven J B Cooper,You Li

doi:10.3390/d13010002

Disentangling the Genetic Relationships of Three Closely Related Bandicoot Species across Southern and Western Australia

Rujiporn Thavornkanlapachai, Margaret Byrne + Show 4 more

Open Access

https://doi.org/10.3390/d13010002

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Journal: Diversity	Publication Date: Dec 22, 2020
Citations: 2	License type: CC BY 4.0

Affiliation: University of Adelaide, South Australian Museum

Abstract

The taxonomy of Australian Isoodon bandicoots has changed continuously over the last 20 years, with recent genetic studies indicating discordance of phylogeographic units with current taxonomic boundaries. Uncertainty over species relationships within southern and western Isoodon, encompassing I. obesulus, I. auratus, and I. fusciventer, has been ongoing and hampered by limited sampling in studies to date. Identification of taxonomic units remains a high priority, as all are threatened to varying extents by ongoing habitat loss and feral predation. To aid diagnosis of conservation units, we increased representative sampling of I. auratus and I. fusciventer from Western Australia (WA) and investigated genetic relationships of these with I. obesulus from South Australia (SA) and Victoria (Vic) using microsatellite markers and mitochondrial DNA. mtDNA analysis identified three major clades concordant with I. obesulus (Vic), I. auratus, and I. fusciventer; however, I. obesulus from SA was polyphyletic to WA taxa, complicating taxonomic inference. Microsatellite data aided identification of evolutionarily significant units consistent with existing taxonomy, with the exception of SA I. obesulus. Further, analyses indicated SA and Vic I. obesulus have low diversity, and these populations may require more conservation efforts than others to reduce further loss of genetic diversity.

Highlights

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.Threatened species often require active management to ensure their persistence
All loci deviated from Hardy–Weinberg equilibrium (HWE) at least in one location, but none consistently deviated from HWE across all locations
Incorrect designation of species and subspecies could lead to inappropriate management decisions that can have detrimental effects such as outbreeding depression, maladaptation, or separating populations when genetic augmentation could benefit inbred populations [3,5,67]

Summary

Introduction

Threatened species often require active management to ensure their persistence. An important first step in threatened species conservation is identifying and defining appropriate units of management to direct conservation effort to where it is needed the most [1,2]. Confusion about taxonomic boundaries of subspecies and other conservation units has the potential to lead to inappropriate management decisions that may have detrimental consequences. Managing populations as separate units, when population sizes are small, may lead to increased levels of inbreeding and loss of adaptive potential due to random genetic drift [5]. Developing an appropriate taxonomic classification that reflects the actual nature of species or subspecies is essential to guide management decisions to improve conservation outcomes

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