Genetic perspectives on the historical introduction of the European rabbit (Oryctolagus cuniculus) to Australia

The introduced European rabbit (Oryctolagus cuniculus) is one of Australia's most damaging invasive alien species, both in terms of ecological and economic impact. Biological control of rabbits using the myxoma and rabbit haemorrhagic disease viruses has been undertaken in Australia since the mid-1950s, and locally varying genetic resistance to these biocontrol viruses has been reported. The efficacy of biocontrol agents may be influenced, among several factors, by the genetic background of rabbit populations. Therefore, understanding the invasion process of rabbits in Australia, and their resultant population structure, remains crucial for enhancing future rabbit management strategies. Using reduced-representation sequencing techniques we genotyped 18 Australian rabbit populations at 7617 SNP loci and show that Australia's invasive rabbits form three broad geographic clusters representing different ancestral lineages, along with a number of highly localised, strongly differentiated lineages. This molecular data supports a history of multiple independent rabbit introductions across the continent followed by regional dispersal, and the resulting patchwork genetic structure may contribute to variation across the country in rabbit resistance to the viral biocontrols. Our study highlights the importance of using genome-wide molecular information to better understand the historical establishment process of invasive species as this may ultimately influence genetic variabilty, disease resistance and the efficacy of biocontrol agents.